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PLOS Medicine logoLink to PLOS Medicine
. 2021 Jun 1;18(6):e1003599. doi: 10.1371/journal.pmed.1003599

Blood pressure-lowering treatment for the prevention of cardiovascular events in patients with atrial fibrillation: An individual participant data meta-analysis

Ana-Catarina Pinho-Gomes 1, Luis Azevedo 2, Emma Copland 3, Dexter Canoy 3,4, Milad Nazarzadeh 3, Rema Ramakrishnan 3, Eivind Berge 5,6, Johan Sundström 7, Dipak Kotecha 8, Mark Woodward 9,10,11, Koon Teo 12, Barry R Davis 13, John Chalmers 9, Carl J Pepine 14, Kazem Rahimi 3,4,*; on behalf of the Blood Pressure Lowering Treatment Trialists’ Collaboration
Editor: Gregory Lip15
PMCID: PMC8168843  PMID: 34061831

Abstract

Background

Randomised evidence on the efficacy of blood pressure (BP)-lowering treatment to reduce cardiovascular risk in patients with atrial fibrillation (AF) is limited. Therefore, this study aimed to compare the effects of BP-lowering drugs in patients with and without AF at baseline.

Methods and findings

The study was based on the resource provided by the Blood Pressure Lowering Treatment Trialists’ Collaboration (BPLTTC), in which individual participant data (IPD) were extracted from trials with over 1,000 patient-years of follow-up in each arm, and that had randomly assigned patients to different classes of BP-lowering drugs, BP-lowering drugs versus placebo, or more versus less intensive BP-lowering regimens. For this study, only trials that had collected information on AF status at baseline were included. The effects of BP-lowering treatment on a composite endpoint of major cardiovascular events (stroke, ischaemic heart disease or heart failure) according to AF status at baseline were estimated using fixed-effect one-stage IPD meta-analyses based on Cox proportional hazards models stratified by trial. Furthermore, to assess whether the associations between the intensity of BP reduction and cardiovascular outcomes are similar in those with and without AF at baseline, we used a meta-regression. From the full BPLTTC database, 28 trials (145,653 participants) were excluded because AF status at baseline was uncertain or unavailable. A total of 22 trials were included with 188,570 patients, of whom 13,266 (7%) had AF at baseline. Risk of bias assessment showed that 20 trials were at low risk of bias and 2 trials at moderate risk. Meta-regression showed that relative risk reductions were proportional to trial-level intensity of BP lowering in patients with and without AF at baseline. Over 4.5 years of median follow-up, a 5-mm Hg systolic BP (SBP) reduction lowered the risk of major cardiovascular events both in patients with AF (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.83 to 1.00) and in patients without AF at baseline (HR 0.91, 95% CI 0.88 to 0.93), with no difference between subgroups. There was no evidence for heterogeneity of treatment effects by baseline SBP or drug class in patients with AF at baseline. The findings of this study need to be interpreted in light of its potential limitations, such as the limited number of trials, limitation in ascertaining AF cases due to the nature of the arrhythmia and measuring BP in patients with AF.

Conclusions

In this meta-analysis, we found that BP-lowering treatment reduces the risk of major cardiovascular events similarly in individuals with and without AF. Pharmacological BP lowering for prevention of cardiovascular events should be recommended in patients with AF.


In an individual patient data meta-analysis, Ana-Catarina Pinho-Gomes and colleagues investigate prevention of cardiovascular events with blood pressure-lowering treatment in those with and without atrial fibrillation.

Author summary

Why was this study done?

  • Atrial fibrillation (AF) is the most common cardiac arrhythmia across the world and is strongly associated with future vascular disease, particularly stroke.

  • Blood pressure (BP) lowering is an established strategy for prevention of vascular disease, but whether patients with AF benefit similarly from pharmacological BP reduction is not well understood.

What did the researchers do and find?

  • We compared the preventive effect of BP-lowering treatment on cardiovascular outcomes in patients with and without AF at baseline.

  • We conducted an individual participant data meta-analysis using published and unpublished data from large randomised clinical trials (22 trials involving 188,570 patients).

  • We showed that BP-lowering treatment reduced the risk of a major cardiovascular events with no evidence that effects differed according to the presence or absence of AF at baseline.

  • The relative risk reductions were proportional to the intensity of BP reduction in individuals with and without AF.

  • In individuals with AF, the relative risk reduction was comparable irrespective of whether baseline systolic BP was under or over the conventional treatment threshold of 140 mm Hg.

What do these findings mean?

  • BP-lowering treatment reduces the risk of major cardiovascular events in patients with AF to a similar extent to that of patients without AF.

  • Pharmacological BP-lowering treatment for prevention of cardiovascular events should be recommended as part of care for patients with AF.

Introduction

Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia and its incidence and prevalence are on the rise across the globe [1,2], mainly due to population ageing and an increase in other cardiometabolic risk factors [3]. In observational studies, AF has been associated with an approximately 90% higher risk of a fatal vascular event, such as stroke, ischaemic heart disease, heart failure (HF), and vascular dementia [4]. Although the risk of stroke, in particular, can be mitigated by anticoagulation, the majority of deaths in contemporary anticoagulated AF patients are due to cardiovascular causes other than stroke, such as myocardial infarction and HF [5,6]. Yet, there is no proven pharmacological intervention other than anticoagulation for effective reduction of such risks [7].

Although high blood pressure (BP) is the most common cardiovascular risk factor in patients with AF [8,9], whether BP lowering reduces the risk of cardiovascular events in patients with AF remains uncertain. As BP-lowering treatment significantly decreases cardiovascular risk in high-risk populations [10], a similar effect could be expected in patients with preexisting AF. However, the complex structural, neurohumoral, and metabolic changes in the cardiovascular system that underpin the development and progression of AF may interfere with BP-lowering treatment [11]. This uncertainty is further compounded by the fact that the only randomised controlled trial (RCT) specifically conducted in patients with AF failed to detect a risk reduction in cardiovascular events using an angiotensin receptor blocker [12]. Several other major BP-lowering trials have included patients with known AF, but the low prevalence of AF rendered them individually underpowered to perform subgroup analysis according to AF status at baseline. We have sought to extract previously published and unpublished data to compare the effect of BP-lowering treatment on fatal and nonfatal cardiovascular outcomes in patients with and without AF overall and by major drug classes.

Methods

Study design

We conducted individual participant data (IPD) meta-analyses of BP-lowering RCTs that investigated treatment effects on cardiovascular outcomes by presence or absence of AF at randomisation. The study was based on the resource provided by the Blood Pressure Lowering Treatment Trialists’ Collaboration (BPLTTC). RCTs are eligible for inclusion in BPLTTC if they have randomised participants to BP-lowering drugs versus placebo or alternative classes of BP-lowering drugs, or between more versus less intensive regimens, and have at least 1,000 patient-years of follow-up in each randomised arm. To date, 50 RCTs have shared data. Details of the methods underlying the latest cycle of the BPLTTC have been recently published and are described in S1 Methods [13]. A separate ethical approval was not required for this study. This analysis followed a prespecified protocol that is available as Supporting information (S1 Protocol).

In this study, only trials that had collected information on AF status at baseline were included. Three types of trials were identified: (1) trials that included both patients with and without AF at baseline; (2) trials that included only patients with AF at baseline; and (3) trials that excluded patients with AF at baseline. We excluded trials in which the presence of AF was not explicitly assessed at baseline or in which AF status at baseline was not clear.

Definition of outcomes

The primary outcome was total cardiovascular events, defined as the first occurrence of (1) fatal or nonfatal stroke; (2) fatal or nonfatal myocardial infarction or ischaemic heart disease; or (3) HF causing death or requiring hospitalisation. Secondary outcomes were the individual elements of the composite endpoint as well as cardiovascular death and all-cause death.

Treatment comparisons

For the main analysis, intervention and control groups were compared. For placebo-controlled trials, the placebo arm was considered as the “comparator” and the active treatment was considered as the “intervention.” For trials with two or more active treatment arms, the arm in which the BP reduction was higher was considered as “intervention” and the other treatment arm(s) as “comparator.” Treatment arms were grouped together whenever required to avoid double counting of participants. S1 Table summarises the treatment comparisons considered in each trial and the difference in systolic BP (SBP) reduction between trial arms.

Risk of bias assessment

We used the Rob2 tool from the Cochrane Collaboration for assessing risk of bias of individual trials. (S2 Table) [14].

Statistical analysis

Our main analyses aimed to address 4 questions: (q1) whether the effect of BP-lowering treatment on CVD outcomes differs between those with and without AF; (q2) whether the associations between the intensity of BP reduction and outcomes are similar in those with and without AF at baseline; (q3) whether in patients with AF, treatment effects vary by baseline SBP; and (q4) whether in patients with AF, treatment effects vary by classes of antihypertensives. Intention-to-treat analysis was adopted using the data provided by each trial, after internal quality checks had been carried out to ensure that data were accurate and transferred without error. Our method for investigating these questions was a one-stage approach that uses IPD from all trials simultaneously and applying a single statistical model. The one-stage approach has more power and flexibility than a two-stage approach to test for treatment-covariate interactions even when few studies are available [15,16]. We used fixed-effect one-stage IPD meta-analysis models for time-to-event data by applying Cox proportional hazard models stratified by trial [17]. The average SBP reduction between arms among all included trials was 3.7 mm Hg (due to inclusion of “head-to-head” comparisons trials) (S1 Table). Thus, we adjusted the estimates for each subgroup (with and without AF) for a 5-mm Hg reduction in SBP. Furthermore, to assess whether the associations between the intensity of BP reduction and cardiovascular outcomes is similar in those with and without AF at baseline (q2), we used analytical and graphical representations of the full meta-regression model with additional terms for AF status and interactions between treatment, difference in SBP, and AF status. This model describes the effects on outcomes for each level of intensity of SBP lowering and for each of the subgroups with and without AF at baseline. Finally, to assess in patients with AF whether treatment effects vary by baseline SBP and by classes of BP-lowering drugs (q3 and q4), we used models only for AF patients with additional terms for these potential moderators and interactions between treatment, difference in SBP, and moderators (S3 and S4 Tables). Further details on our statistical modelling approach, subgroup analyses, and sensitivity analyses are provided in S1 Methods. Statistical analyses were performed using R version 3.6.1. This study is reported as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline (S1 PRISMA Checklist).

Results

From the full BPLTTC database, 28 trials (145,653 participants) were excluded because AF status at baseline was uncertain or unavailable. Twenty-two trials were eligible and provided data for the IPD meta-analyses (S5 and S6 Tables and Fig 1). Seven of these trials had previously published data about AF status at baseline. The 22 trials included 188,570 individuals, of whom 13,266 (7%) had AF at baseline [12,1833]. Seven trials explicitly excluded participants with AF at baseline (N = 13,170, 7% of the participants without AF at baseline) [21,3437], and one trial included only those with prevalent AF (N = 9,016, 67% of the participants with AF at baseline) [12]. The remaining 14 trials included a mixed population of participants with and without AF at baseline (4,249 with AF and 153,198 without AF). All trials contributed data for all the outcomes of interest, with the exception of 2 trials that did not report the HF outcome [19,23] and one trial that did not report cardiovascular death [35]. Risk of bias assessment showed that 20 trials had low risk of bias and 2 trials had moderate risk (S2 Table). There was no evidence of acquisition bias based on funnel plot and Egger’s regression test (S1 Fig).

Fig 1. PRISMA diagram for included trials.

Fig 1

AF, atrial fibrillation; BPLTTC, Blood Pressure Lowering Treatment Trialists’ Collaboration; IPD, individual participant data; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Patients with AF were older than those without AF (mean age 70 versus 65 years, respectively) (Table 1). A lower baseline SBP and diastolic BP (DBP) was evident in patients with AF, who were more commonly prescribed diuretics, angiotensin-converting enzyme inhibitors, beta-blockers, and alpha-blockers: 143/84 mm Hg (SD 21/12 mm Hg) versus 155/88 mm Hg (SD 21/13 mm Hg) in patients without AF, respectively. Cerebrovascular disease was more common in patients with AF, while ischaemic heart disease, diabetes mellitus, and chronic kidney disease were more common in patients without AF. The prevalence of smoking was higher in patients with AF than in those without AF (9.3% versus 24.3%, respectively).

Table 1. Baseline characteristics of participants by atrial fibrillation status at baseline.

Atrial fibrillation (N = 13,266) No atrial fibrillation (N = 175,304) Total (N = 188,570)
Age (years) 70.19 (9.12) 65.36 (9.05) 65.70 (9.14)
Sex (Female) 5,052 (38.1) 73,182 (41.7) 78,235 (41.5)
Ischaemic heart disease 3,923 (29.6) 56,759 (32.4) 60,682 (32.2)
Cerebrovascular disease 2,395 (18.5) 21,788 (15.5) 24,183 (15.7)
Diabetes mellitus 3,569 (26.9) 54,209 (32.2) 57,778 (31.8)
Chronic kidney disease 163 (20.3) 15,600 (25.4) 15,763 (25.3)
Heart failure 2,882 (31.9) 0 (0) 2,882 (31.9)
Smoking (current) 1,224 (9.3) 38,283 (24.3) 39,507 (23.1)
Body mass index (kg/m2) 28.78 (5.60) 28.12 (9.67) 28.16 (9.44)
Total cholesterol (mmol/L) 5.3 (1.2) 5.6 (1.2) 5.6 (1.2)
Systolic blood pressure (mm Hg) 142.8 (20.9) 154.6 (21.6) 153.82 (21.72)
Diastolic blood pressure (mm Hg) 83.6 (11.7) 87.8 (12.6) 87.49 (12.58)
Pharmacological treatment
 Diuretic 6,082 (50.8) 19,196 (23.8) 25,278 (27.3)
 Alpha-blocker 1,134 (10.7) 2,813 (4.4) 3,947 (5.2)
 Beta-blocker 6,133 (51.3) 29,013 (36.0) 35,146 (38.0)
 Angiotensin-converting enzyme inhibitor 6,846 (59.6) 32,290 (44.0) 39,136 (46.1)
 Angiotensin receptor blocker 568 (5.4) 6,420 (15.0) 6,988 (13.1)
 Calcium channel blocker 3,557 (29.7) 29,566 (36.7) 33,123 (35.8)
 Anticoagulant 4,418 (37.8) 1,823 (3.1) 6,241 (8.9)
 Antiplatelet 6,443 (56.1) 35,539 (49.3) 41,982 (50.2)
 Lipid-lowering drug 3,742 (32.8) 31,100 (42.6) 34,842 (41.3)

All categorical variables are summarised as N (% yes); all continuous variables as mean (standard deviation).

In placebo-controlled trials (8 trials), the difference in SBP reduction between arms was 7.2 (SD 3.9) mm Hg; in drug–drug comparisons (12 trials), it was 2.3 (SD 0.9) mm Hg; and in more versus less intensive BP lowering (2 trials), it was 10.9 (SD 3.0) mm Hg. Overall, the mean difference in SBP reduction between intervention and control arms was 3.7 (SD 3.2) mm Hg, and that was similar in patients with and without AF (3.3 (SD 2.0) mm Hg versus 3.7 (SD 3.3) mm Hg for patients with and without AF, respectively).

Meta-regression showed that there was a linear association between the degree of SBP lowering and the reduction in the hazard ratio (HR) for major cardiovascular events both in patients with and without AF at baseline (Fig 2).

Fig 2. Hazard ratio of major cardiovascular events related to the 1-year difference blood pressure reduction aggregated at trial level.

Fig 2

Risk of major cardiovascular events, for patients with (dashed line) and without (solid line) atrial fibrillation at baseline, regressed against the systolic blood pressure difference between trial arms, plotted on the log scale. Shapes represent the hazard ratio for each trial with the size inversely proportional to the respective standard error. Trials are coded by shape according to the type of patients: atrial fibrillation only (triangle), no atrial fibrillation only (square), and mix of both (circles). Trials are also coded by colour according to type of intervention: placebo-controlled trials (red), drug class comparison trials (blue), and more versus less intense treatment trials (green). Systolic blood pressure difference between trial arms in mm Hg.

Over a median follow up of 4.5 years (interquartile range 3.8 to 5.3), 3,674 (27.8%) and 21,380 (12.2%) patients with and without AF, respectively, developed a major cardiovascular event. This translates into a rate of major cardiovascular events of 73 and 28 per 1,000 patient-years for patients with and without AF, respectively (Fig 3). Each 5 mm Hg SBP lowering reduced the risk of major cardiovascular events by about 10% in patients with and without AF at baseline (HR 0.91, 95% confidence interval (CI) [0.83 to 1.00] versus HR 0.91, 95% CI [0.88 to 0.93] for patients with and without AF at baseline, respectively) (Figs 3 and 4). Furthermore, there was no evidence that the risk reduction for any of the primary and secondary outcomes achieved by BP-lowering treatment was different between patients with and without AF (Fig 4). Adjustment for the average reduction in SBP of 3.7 mm Hg was consistent with our main adjustment to 5 mm Hg SBP reduction and showed no difference between patients with and without AF (S2 Fig).

Fig 3. Cumulative event rates for the primary outcome (major cardiovascular events) by treatment arm, stratified by presence of atrial fibrillation at baseline.

Fig 3

Shown are estimates of the proportions of patients with major cardiovascular events (primary composite endpoint) according to treatment arm (intervention versus comparator as defined in treatment comparisons in the methods) for patients with atrial fibrillation (top lines) and without atrial fibrillation at baseline (bottom lines). These curves were created for the overall population included in this study without accounting for stratification by trial.

Fig 4. Effect of blood pressure lowering treatment on primary and secondary outcomes, stratified by presence of atrial fibrillation at baseline.

Fig 4

Forest plot displays the HRs and 95% CIs for each outcome adjusted for a 5-mm Hg systolic blood pressure reduction. Further details on adjustment provided in the Methods. P values for test of difference between subgroups. CI, confidence interval; HR, hazard ratio.

Subgroup analysis in patients with AF showed no evidence that the relative risk reduction in major cardiovascular events varied according to baseline SBP (test for linear trend P = 0.992). There was also no difference in treatment effects between patients with baseline SBP below and above 140 mmHg (P = 0.792) (Fig 5).

Fig 5. Effect of blood pressure-lowering treatment on major cardiovascular events stratified by baseline systolic blood pressure in patients with atrial fibrillation.

Fig 5

Forest plot displays the HRs and 95% CIs for major cardiovascular events for a 5-mm Hg systolic blood pressure reduction in patients with atrial fibrillation with baseline systolic blood pressure below or above 140 mm Hg. P value for test of difference between subgroups. CI, confidence interval; HR, hazard ratio.

Six trials were included in the comparison of renin-angiotensin-aldosterone system (RAAS)-inhibitors versus placebo or standard treatment (i.e., beta-blocker and/or diuretic), including 56,649 participants. Four trials were included in the comparison of calcium channel blockers (CCB)-based regimens versus placebo or standard treatment (i.e., beta-blocker and/or diuretic), including 44,288 participants. There was no evidence of a difference in the effects of treatment regimens based on RAAS inhibitors or CCB between patients with and without AF at baseline (P = 0.245 and P = 0.909 for RAAS-based and CCB-based regimens, respectively) (Fig 6). However, the CIs were wide due to the relatively small number of AF participants.

Fig 6. Effect of blood pressure-lowering treatment on major cardiovascular events stratified by drug class.

Fig 6

Forest plot displays the HRs and 95% CIs for major cardiovascular events for a 5-mm Hg systolic blood pressure reduction for RAAS inhibitors-based and CCB-based regimens in comparison with placebo or BB with or without Diu. P values for test of difference between subgroups. BB, beta-blocker; CCB, calcium channel blocker; CI, confidence interval; Diu, diuretic; HR, hazard ratio; RAAS, renin-angiotensin-aldosterone system.

Sensitivity analysis using only trials that contributed to both subgroups, that is the 14 trials that included both participants with and without AF at baseline and thus allowed estimation of the within-trial interaction between treatment and AF at baseline, showed broadly similar results to those from the main analyses. However, the smaller sample size meant that the CIs were wider, particularly in patients with AF at baseline (S7 Table). Sensitivity analysis using a two-stage approach yielded similar estimates to the one-stage approach overall and for subgroup analysis according to AF status at baseline (S8 Table). Several additional sensitivity analyses were requested by the reviewers which were conducted and broadly supported our main findings: We reran the models using an unadjusted approach for SBP and found no material change in our results (S9 Table). The results of fixed and random effects two-stage models were consistent and further supported the robustness of the main model (S8 Table). To rule out the effects of treatment in ACTIVE-I trial were driven by inclusion of patients with HF, we conducted a sensitivity analysis in which we excluded the patients with a diagnosis of HF at baseline in ACTIVE-I trial. As shown in S10 Table, results were consistent with our main analysis. Additional adjustment for baseline SBP, cardiovascular disease status, and diabetes at baseline had no impact on our main findings (S11 Table). Finally, no material change was also seen after excluding the trials with moderate risk of bias (S12 Table).

Discussion

This study showed that BP-lowering treatment affords a similar relative risk reduction in major cardiovascular events in patients with and without AF, with no evidence that treatment effects differed between those subgroups for any of the primary and secondary outcomes. Overall, each 5-mm Hg reduction in SBP resulted in an approximately 10% lower risk of major cardiovascular events both in patients with and without AF at baseline. Furthermore, there was no evidence that in patients with AF the relative risk reduction varied according to baseline SBP [38].

Although absolute risks are better estimated from population-based observational studies, the almost 3-fold higher event rate that we observed in patients with AF at baseline compared with those without AF reflects their higher cardiovascular risk. This is in keeping with previous observational studies which reported that AF was associated with a 2- to 5-fold higher risk of major cardiovascular events in comparison with patients without AF [4,39,40]. Therefore, the same relative risk reduction afforded by BP-lowering treatment would most likely achieve a greater absolute risk reduction in patients with AF than in patients without AF at baseline.

It is thus a paradox that much of the focus of AF-related research has been on anticoagulation for stroke prevention, and strategies for rate-control or restoration of sinus rhythm, when the relative and absolute risk for cardiovascular events like HF and ischaemic heart disease is greater than that of stroke in patients with AF [40]. In addition, even with optimal anticoagulation and rate or rhythm control, the risk of stroke in patients with AF remains high (about 1.5% per year) [41] and it seems to result from associated risk factors rather than treatment failure [42,43]. Therefore, management of associated cardiovascular risk factors, among which high BP with an estimated prevalence of 70% is the most common, seems a priority to improve cardiovascular outcomes and survival in the high-risk group of patients with AF [44]. In this context, our study provides compelling evidence that pharmacological BP-lowering treatment is an effective strategy to prevent cardiovascular events overall as well as to address the residual risk of stroke.

Although the most recent AF guidelines issued by the European Society of Cardiology state that “good blood pressure control should form an integral part of the management of AF patients,” randomised evidence has been lacking to support those recommendations [7]. This uncertainty underpins the cautious AF guidelines of the American College of Cardiology, which despite mentioning that “appropriate control of risk factors like hypertension substantially reduces stroke risk,” make no specific recommendations about BP management in patient with AF [9]. Thus far, evidence on potential importance of BP reduction in patients with AF comes from observational studies, wherein the ideal SBP target for the prevention of cardiovascular events was found to be in the range of 120 to 129 mmHg [4]. Our study fills this gap in randomised evidence. We found that patients with AF included in trials had a relatively low baseline SBP, with almost half of them having a SBP of less than 140 mmHg prior to randomisation, commonly not recommended for treatment [38].

Hypertension guidelines recommend that drugs with shared rate- and BP-lowering properties (e.g., non-dihydropyridine CCBs and beta-blockers) should be preferred in patients with AF and high BP [38,45]. However, those recommendations are based on the indication of those drugs for rate control as thus far whether pharmacological BP lowering decreases cardiovascular risk in patients with AF has not been demonstrated. In addition, the lack of evidence for class-specific effects together with the linear association between the HR for major cardiovascular events and the intensity of SBP reduction showed in this study suggest that the intensity of BP lowering is more important than the specific drugs used to achieve it when it comes to prevention cardiovascular events. Therefore, until further research clarifies whether any drug class can achieve superior risk reduction for equivalent BP reduction, BP lowering irrespective of the drug class should be viewed as an effective strategy to decrease the high cardiovascular risk of patients with AF.

The main strength of this IPD meta-analysis is the analysis of the effects of BP-lowering treatment in a large number of patients with baseline AF included into RCTs, their comparison with patients without AF, the long follow-up time, and the more than 20,000 major cardiovascular events. The robustness of the main conclusions to sensitivity analyses and the consistency of the estimates provided by different methods further support the conclusions drawn. However, some limitations deserve to be acknowledged. First, there is a possibility of selection bias, as IPD was not obtainable for all the trials eligible for inclusion in the BPLTTC. While it remains uncertain whether those trials had collected data on AF status at baseline, it seems unlikely that lack of contribution to the BPLTTC has biased our estimates. This is supported by the consistency of the effects of BP reduction on cardiovascular outcomes in our set of studies with the estimates in a more comprehensive, albeit tabular meta-analysis (roughly 10% relative risk reduction per 5 mm Hg SBP reduction) [10]. Second, the number of participants with AF was modest considering the total number of participants in the BPLTTC dataset because only a fraction of the trials reported AF at baseline and the relatively low rate of AF in the trial populations. On the other hand, this means that even if a degree of misclassification is present due to omitted disclosure or the paroxysmal nature of the arrhythmia, a material impact on treatment effect estimates would be unlikely. Third, although it would have been interesting to compare the effects of other drug classes, particularly in head-to-head comparisons, only a small fraction of the trials included in the BPLTTC reported AF at baseline and were thus eligible for this study. Fourth, although concerns have been raised about the variability of BP measurement in patients with AF, which could have biased our estimates, there was no evidence of this in our population [46]. Finally, much of the weight of the analysis in the current report was driven by the ACTIVE-I trial, which included about 30% of patients with HF. However, excluding the HF patients from the analysis did not have a material impact on our findings of no interaction between AF status at baseline and the effect of BP lowering treatment.

In conclusion, this study demonstrated that BP-lowering treatment reduces the risk of major cardiovascular events in patients with AF to a similar extent to that of patients without AF, with no evidence that treatment effects varied according to baseline SBP or drug class. Owing to their higher absolute cardiovascular risk, treatment in patients with AF is likely to result in greater absolute risk reduction than in patients without AF. Clinical guidelines should be updated to recommend pharmacological BP lowering for prevention of cardiovascular events in patients with AF.

Supporting information

S1 Fig. Funnel plot for assessment of publication (acquisition) bias on the effect of blood pressure reduction and risk of major cardiovascular event.

(DOCX)

S2 Fig. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by presence of atrial fibrillation at baseline and adjusted for a 3.7-mm Hg systolic blood pressure reduction.

(DOCX)

S1 Table. Difference in systolic blood pressure reduction between arms for each trial.

(DOCX)

S2 Table. Assessment of risk of bias.

(DOCX)

S3 Table. Number of trials available for drug class comparisons.

(DOCX)

S4 Table. Treatment comparisons for subgroup analyses by drug class.

(DOCX)

S5 Table. Summary of included trials.

(DOCX)

S6 Table. Baseline characteristics of the participants included in atrial fibrillation meta-analyses stratified by trial.

(DOCX)

S7 Table. Sensitivity analyses including only trials that included patients with and without atrial fibrillation at baseline.

(DOCX)

S8 Table. Fixed and random effects two-stage meta-analyses.

(DOCX)

S9 Table. Unadjusted effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline.

(DOCX)

S10 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, excluding the patients with the diagnosis of heart failure at baseline in ACTIVE-I trial.

(DOCX)

S11 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, after adjustment for baseline systolic blood pressure, cardiovascular disease status, and diabetes status at baseline.

(DOCX)

S12 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, excluding the trials with moderate risk of bias.

(DOCX)

S1 Methods

(DOCX)

S1 PRISMA Checklist

(DOCX)

S1 Protocol

(DOCX)

Acknowledgments

Writing group: Ana-Catarina Pinho-Gomes (King’s College London, London, United Kingdom), Luis Azevedo (Centre for Health Technology and Services Research, University of Porto, Porto, Portugal), Emma Copland (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom), Dexter Canoy (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom), Milad Nazarzadeh (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom), Rema Ramakrishnan (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom), Eivind Berge (Department of Cardiology, Oslo University Hospital, Oslo, Norway),†Johan Sundström (Department of Medical Sciences, Uppsala University, Sweden),7 Dipak Kotecha (Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom), Mark Woodward (The George Institute for Global Health, University of New South Wales, Sydney, Australia), Koon Teo (Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada), Barry R Davis (The University of Texas School of Public Health, Houston, Texas, United States),13 John Chalmers (The George Institute for Global Health, University of New South Wales, Sydney, Australia),9 Carl J. Pepine (Department of Medicine, University of Florida, Gainesville, Florida, United States),14 Kazem Rahimi (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom))3,4.

† Deceased.

Core analytic group: Zeinab Bidel, Milad Nazarzadeh, Emma Copland and Dexter Canoy (Deep Medicine, Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford, United Kingdom).

Steering Committee: Kazem Rahimi (Chair) (Deep Medicine, University of Oxford, Oxford, United Kingdom), Koon Teo (Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada) Barry R Davis (The University of Texas School of Public Health, Houston, Texas, USA), John Chalmers (The George Institute for Global Health, University of New South Wales, Sydney, Australia), Carl J. Pepine (Department of Medicine, University of Florida, Gainesville, Florida, USA).

Collaborating Trialists: A Adler (UKPDS [UK Prospective Diabetes Study]), L Agodoa (AASK [African-American Study of Kidney Disease and Hypertension]), A Algra (Dutch TIA Study [Dutch Transient Ischemic Attack Study]), F W Asselbergs (PREVEND-IT [Prevention of Renal and Vascular End- stage Disease Intervention Trial]), N Beckett (HYVET [Hypertension in the Very Elderly Trial]), E Berge (deceased) (VALUE trial [Valsartan Antihypertensive Long-term Use Evaluation trial]), H Black (CONVINCE [Controlled Onset Verapamil Investigation of Cardiovascular End Points]), F.P.J. Brouwers (PREVEND-IT), M Brown (INSIGHT [International Nifedipine GITS Study: Intervention as a Goal in Hypertension]), C J Bulpitt (HYVET), B Byington (PREVENT [Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial]), J Chalmers (ADVANCE [Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation]), WC Cushman ((ACCORD [Action to Control Cardiovascular Risk in Diabetes], ALLHAT, SPRINT [Systolic Blood Pressure Intervention Trial]), J Cutler (ALLHAT [Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial]), B R Davis (ALLHAT), R B Devereaux (LIFE [Losartan Intervention For Endpoint reduction in hypertension]), D Dwyer (IDNT [Irbesartan Diabetic Nephropathy Trial]), R Estacio (ABCD [Appropriate Blood Pressure Control in Diabetes]), R Fagard (SYST-EUR [SYSTolic Hypertension in EURope]), K Fox (EUROPA [European trial on Reduction Of cardiac events with Perindopril among patients with stable coronary Artery disease]), T Fukui (CASE-J [Candesartan Antihypertensive Survival Evaluation in Japan]), A K Gupta (ASCOT [Anglo-Scandinavian Cardiac Outcomes Trial]), R R Holman (UKPDS [UK Prospective Diabetes Study]), Y Imai (HOMED-BP [Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure]), M Ishii (JMIC-B [Japan Multicenter Investigation for Cardiovascular Diseases-B]), S Julius (VALUE), Y Kanno (E-COST [Efficacy of Candesartan on Outcome in Saitama Trial]), S E Kjeldsen (VALUE, LIFE), J Kostis (SHEP [Systolic Hypertension in the Elderly Program]) K Kuramoto (NICS-EH [National Intervention Cooperative Study in Elderly Hypertensives]), J Lanke (STOP2 [Swedish Trial in Old Patients with Hypertension-2], NORDIL [Nordic Diltiazem]), E Lewis (IDNT), J B Lewis (IDNT) M Lievre (DIABHYCAR [Non-insulin-dependent diabetes, hypertension, microalbuminuria or proteinuria, cardiovascular events, and ramipril study]), L H Lindholm (CAPPP [Captopril Prevention Project], STOP2, NORDIL), S Lueders (MOSES [The Morbidity and Mortality After Stroke, Eprosartan Compared With Nitrendipine for Secondary Prevention]), S MacMahon (ADVANCE), G Mancia (INSIGHT), M Matsuzaki (COPE [The Combination Therapy of Hypertension to Prevent Cardiovascular Events]), M H Mehlum (VALUE), S Nissen (CAMELOT [Comparison of Amlodipine vs Enalapril to Limit Occurrences of Thrombosis]), H Ogawa (HIJ-CREATE [Heart Institute of Japan Candesartan Randomized Trial for Evaluation in Coronary Heart Disease]), T Ogihara (CASE-J), T Ohkubo (HOMED-BP), C Palmer (INSIGHT), A Patel (ADVANCE), C J Pepine (INVEST [International Verapamil SR-Trandolapril Study]), M Pfeffer (PEACE [Prevention of Events With Angiotensin- Converting Enzyme Inhibition]), B Pitt (PREVENT), N R Poulter (ASCOT [Anglo-Scandinavian Cardiac Outcomes Trial]), H Rakugi (VALISH [Valsartan in Elderly Isolated Systolic Hypertension Study], CASE-J), G Reboldi (Cardio-Sis [CARDIOvascolari del Controllo della Pressione Arteriosa SIStolica]), C Reid (ANBP2 [The Second Australian National Blood Pressure Study]), G Remuzzi (BENEDICT [BErgamo NEphrologic DIabetes Complications Trial]), P Ruggenenti (BENEDICT), T Saruta (CASE-J), J Schrader (MOSES), R Schrier (deceased) (ABCD), P Sever (ASCOT), P Sleight (deceased) (CONVINCE, HOPE [Heart Outcomes Prevention Evaluation], TRANSCEND [Telmisartan Randomised AssessmeNt Study in ACE iNtolerant subjects with cardiovascular Disease], ONTARGET [Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial]), J A Staessen (SYST-EUR [Systolic Hypertension in Europe]), H Suzuki (ECOST), L Thijs (Syst-Eur), K Ueshima (VALISH, CASE-J), S Umemoto (COPE), W H van Gilst (PREVEND-IT), P Verdecchia (Cardio-Sis [CARDIOvascolari del Controllo della Pressione Arteriosa SIStolica]), K Wachtell (LIFE), P Whelton (SPRINT), L Wing (ANBP2 [The Second Australian National Blood Pressure Study]), M Woodward (ADVANCE, PROGRESS), Y Yui (JMIC-B), S Yusuf (HOPE, ONTARGET, TRANSCEND), A Zanchetti (deceased) (VHAS [Verapamil in Hypertension and Atherosclerosis Study], ELSA [European Lacidipine Study on Atherosclerosis]), Z Y Zhang (Syst-Eur).

Other members: C Anderson, C Baigent, BM Brenner, R Collins, D de Zeeuw, J Lubsen, E Malacco, B Neal, V Perkovic, A Rodgers, P Rothwell, G Salimi-Khorshidi, J Sundström, F Turnbull, G Viberti, J Wang.

Abbreviations

AF

atrial fibrillation

BP

blood pressure

BPLTTC

Blood Pressure Lowering Treatment Trialists’ Collaboration

CCB

calcium channel blockers

CI

confidence interval

DBP

diastolic BP

HF

heart failure

HR

hazard ratio

IPD

individual participant data

PRISMA

Preferred Reporting Items for Systematic Reviews and Meta-Analyses

RAAS

renin-angiotensin-aldosterone system

RCT

randomised controlled trial

SBP

systolic BP

Data Availability

The governance of BPLTTC and policies on data access and sharing policies are described elsewhere (Rahimi K, et al. BMJ Open 2019;9:e028698). Our data sharing agreements with our collaborators limit us from sharing the original data to third parties. However, a governance framework exists for collaborative projects with external research investigators. For further queries, please check www.bplttc.org for our contact details.

Funding Statement

The following authors are supported by grants from the British Heart Foundation “ACPG, KR & DC (grant number: FS/19/64/34673), KR & DC (grant number: PG/18/65/33872), MN, KR & DC (grant number FS/19/36/34346); KR is also in receipt of funding from the UKRI’s Global Challenges Research Fund (Grant Ref ES/P011055/1), the Oxford NIHR Biomedical Research Centre, and the Oxford Martin School at University of Oxford. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR or the Department of Health and Social Care. This manuscript was prepared using ACCORD, ALLHAT and SHEP Research Materials obtained from the NHLBI Biologic Specimen and Data Repository Information Coordinating Centre and does not necessarily reflect the opinions or views of the ACCORD, ALLHAT and SHEP, or the NHLBI.

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Decision Letter 0

Adya Misra

1 May 2020

Dear Dr Rahimi,

Thank you for submitting your manuscript entitled "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" for consideration by PLOS Medicine.

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Senior Editor

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Decision Letter 1

Emma Veitch

15 Jul 2020

Dear Dr. Rahimi,

Thank you very much for submitting your manuscript "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" (PMEDICINE-D-20-01625R1) for consideration at PLOS Medicine.

Your paper was evaluated by a senior editor and discussed among all the editors here. It was also discussed with an academic editor with relevant expertise, and sent to independent reviewers, including a statistical reviewer. The reviews are appended at the bottom of this email and any accompanying reviewer attachments can be seen via the link below:

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We expect to receive your revised manuscript by Aug 05 2020 11:59PM. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

We ask every co-author listed on the manuscript to fill in a contributing author statement, making sure to declare all competing interests. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. If new competing interests are declared later in the revision process, this may also hold up the submission. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT. You can see our competing interests policy here: http://journals.plos.org/plosmedicine/s/competing-interests.

Please use the following link to submit the revised manuscript:

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Your article can be found in the "Submissions Needing Revision" folder.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see http://journals.plos.org/plosmedicine/s/submission-guidelines#loc-methods.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

We look forward to receiving your revised manuscript.

Sincerely,

Emma Veitch, PhD

PLOS Medicine

On behalf of Clare Stone, PhD, Acting Chief Editor,

PLOS Medicine

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Requests from the editors:

*Although two reviewers are relatively positive about the paper, one reviewer (reviewer 2) raises substantial concerns about the selectivity of inclusion of data in this IPD meta, among other issues - for the paper to be considered potentially publishable in PLOS Medicine, the authors would need to come up with a convincing rebuttal to those points. In addition although the authors' Discussion limitations section mentions some aspects of the analyses, the exact point raised by this reviewer does not seem to be mentioned there.

*Some minor style changes (to be addressed alongside the reviewers' points) - In the last sentence of the Abstract Methods and Findings section, please include a brief note about any key limitation(s) of the study's methodology.

*At this stage, we ask that you include a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract. Please see our author guidelines for more information: https://journals.plos.org/plosmedicine/s/revising-your-manuscript#loc-author-summary

*We would ask that the authors state clearly in the Methods section of the paper whether the analysis presented here corresponds to one laid out in a prospectively-specified protocol or analysis plan? Please state this (either way) early in the Methods section.

a) If a prospective analysis plan (from your funding proposal, IRB or other ethics committee submission, study protocol, or other planning document written before analyzing the data) was used in designing the study, please include the relevant prospectively written document with your revised manuscript as a Supporting Information file to be published alongside your study, and cite it in the Methods section. A legend for this file should be included at the end of your manuscript.

b) If no such document exists, please make sure that the Methods section transparently describes when analyses were planned, and when/why any data-driven changes to analyses took place.

c) In either case, changes in the analysis-- including those made in response to peer review comments-- should be identified as such in the Methods section of the paper, with rationale.

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Comments from the reviewers:

Reviewer #1: See attachment

Michael Dewey

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Reviewer #2: Dear Editors of PLOS Medicine,

Thank you for the opportunity to review this manuscript by Prof. Kazem Rahimi and colleagues. This is an individual-participant data meta-analysis from the Blood Pressure Treatment Trialists Collaboration (BPLTTC), aiming to assess if the effect of blood pressure (BP) lowering treatment differs between people with and without atrial fibrillation (AF), and if treatment effect in people with AF differs by baseline BP level and choice of antihypertensive agent.

Firstly, the authors should be complemented for the effort to update of the BPLTTC database. This will surely be of great importance to the field for years to come. Further, the manuscript is well written, with clear graphs and tables.

Unfortunately, I have several major concerns that needs to be addressed. Firstly, this meta-analysis does not build on a systematic review of the literature. This is problematic, because inclusion of certain (not all of the available) trials may provide biased results, not representative of the totality of the available evidence. For example, the five-year-old meta-analysis by Ettehad et al.1, with similar inclusion criteria, included 123 trials, whereas the updated BPLTTC database includes 50 trials, of which 22 are included in this analysis. Without an underlying systematic review, it is not possible to assess the generalizability of the reported findings. When undertaking such a massive effort as updating the BPLTTC dataset, it would be a small thing to perform an updated systematic review, trying to find all available trials, thereby being able to assess the representativeness of the trials providing IPD.

Secondly, also relating to the fact that this is not a systematic review, the authors present no risk of bias assessment of the included trials. This is a major concern, primarily because it makes it impossible for the reader to appraise the validity of the results from the meta-analysis (a meta-analysis is only as good as the included trials, and this is not reported), but also because it is a deviation from the meta-analysis protocol, published last year.2

Thirdly, the main advantage of IPD in a meta-analysis setting is to better be able to select and group participants, based on individual characteristics. Used correctly, this will minimize ecological bias and confounding by differences in baseline covariates between groups. This paper hasn't used the available IPD as efficient as possible. For example, in the ACTIVE-I trial (I'll come back to that), contributing with 67% of AF participants in this meta-analysis, one third of participants had heart failure (HF) at baseline.3 These participants likely had lower BP and benefited more from treatment compared to non-HF participants; and would have been managed according to HF guidelines (not hypertension guidelines) in clinical practice. Including such participants in an IPD meta-analysis on the effects of blood pressure lowering treatment will I) bias the results towards more positive findings in people with AF and low BP, II) impair the clinical usefulness of the results because they do not necessarily apply to non-HF patients.

Fourthly, inclusion of trials in which all participants had AF, and trials where none of the included participants had AF, greatly increases the risk of ecological bias. If only trials including both AF and non-AF participants would have been included, AF and non-AF participants would have been judged according to the same eligibility criteria, received the same intervention and control, and the same follow-up procedures, including event adjudication etc. Differences in baseline characteristics would still have been present, but these would have been small, and at least trial-level factors would have been similar. In the current analysis, the majority of participants in the AF group comes from one trial (ACTIVE-I), which was limited to AF participants only. This results in massive differences in age, baseline BP level, and concomitant treatment between groups. Further, it means AF and non-AF participants in the meta-analysis have been judged according to different eligibility criteria (trial level), received different interventions, and different follow-up.

Fifthly, several decisions and interpretations relating the statistical methods are questionable.

1. The authors (correctly) state that "Due to different settings and patient populations, the trials included in a meta-analysis are likely to have different baseline hazard functions…" as a motivation for why they stratified their Cox model. In the next sentence they go on stating they chose fixed-effects model for their meta-analysis. This makes no sense, given that the fixed-effects model builds on the assumption of one common treatment effect in all trials. This seems careless rather than "parsimonious", which is the argument used in the supplementary methods section. Cornell et al. discuss how to estimate uncertainty in case of heterogeneity (which was present in the current analysis).4

2. The authors "standardize" the results of each trial to 5 mmHg BP difference between groups. In the best-case scenario, this exaggerates the estimated treatment effect by about 30% (because the actual difference was 3.7 mmHg). In the worst-case scenario, this causes biased results due to shifts in weight between trials, as shown by Brunström et al. and discussed by Thomopoulos.5, 6

3. At several occasions, the authors use underpowered analyses to motivate their choices of statistical methods, and to draw conclusions about possible interactions. For example, heterogeneity analyses should never be used to decide whether to use fixed- or random-effects model.7 Especially in situations like this, when the sample size of AF patients is relatively small, the test for heterogeneity will fail to detect fairly large differences in treatment effects because of the large standard error in the AF groups. Further, research question 3 and 4, regarding the possible interaction between baseline BP and treatment effect, and choice of agent and treatment effect, cannot be answered by the available data. As is evident from Figure 4 and 5, confidence intervals are wide, e.g. spanning from 0.76 to 1.06 for the <140 mmHg group in the BP analysis, reflecting the low number of participants and events. Indeed "no evidence for an association" is not the same as "evidence for no association"; this is not reflected in the authors' interpretations. Specifically, the conclusion that BP lowering is beneficial in AF patients, even below SBP 140 mmHg, stated in the abstract as well as the full text conclusion, is not supported by the data.

Minor issues:

- Inclusion criteria are different in abstract and methods; 1000 patient-years per trial or treatment arm?

- Numbers in fig 4 does not add up. 2982+3566 ≠ 6837; 3091+3615 ≠ 6429 etc. Numbers in BP strata are not compatible with numbers in Fig 3.

1. Ettehad D, Emdin CA, Kiran A, et al. Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis. Lancet 2016; 387: 957-67.

2. Rahimi K, Canoy D, Nazarzadeh M, et al. Investigating the stratified efficacy and safety of pharmacological blood pressure-lowering: an overall protocol for individual patient-level data meta-analyses of over 300 000 randomised participants in the new phase of the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC). BMJ Open 2019; 9: e028698.

3. Yusuf S, Healey JS, Pogue J, et al. Irbesartan in Patients with Atrial Fibrillation. New England Journal of Medicine 2011; 364: 928-38.

4. Cornell JE, Mulrow CD, Localio R, et al. Random-Effects Meta-analysis of Inconsistent Effects: A Time for Change. Annals of Internal Medicine 2014; 160: 267-70.

5. Brunström M, Carlberg B. Standardization according to blood pressure lowering in meta-analyses of antihypertensive trials: comparison of three methodological approaches. J Hypertens 2018; 36: 4-15.

6. Thomopoulos C, Michalopoulou H. Outcome standardization to blood pressure reduction in meta-analyses: sailing in uncharted waters. J Hypertens 2018; 36: 31-3.

7. Cornell JE, Mulrow CD, Localio R, et al. Random-effects meta-analysis of inconsistent effects: a time for change. Ann Intern Med. 2014; 160(4):267-270.

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Reviewer #3: this study aimed to compare the effects of blood pressure (BP)-lowering drugs in patients with and without atrial fibrillation (AF) at baseline. The authors conclude that BP-lowering treatment reduces the risk of major cardiovascular events similarly in individuals with and without AF. Pharmacological BP lowering for prevention of cardiovascular events should be recommended in patients with AF even if BP is below the conventional 140-mmHg threshold.

This paper is generally nicely written and analysed

While there has not been a specific RCT in AF, some large observational studies on the optimal BP targets have been published eg from the Yonsei group in S Korea (Joung B and team).

These should be discussed in the Discusion, notwithstanding that observational cohorts are not a substitute for RCTs

Figure 4 is simplistic - BP is not a yes/no parameter - show the impact on outcomes with BP as a continuous variable, for stroke, major CV events, all cause mortality etc

Figure 5 should how lump together 'placebo or BB/Diu'

Ideally show a summary forrest plot of the different drug classes vs placebo, even to illustrate the effect sizes

Forest plot can also show inter-drug class comparisons

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Any attachments provided with reviews can be seen via the following link:

[LINK]

Decision Letter 2

Adya Misra

26 Oct 2020

Dear Dr. Rahimi,

Thank you very much for submitting your manuscript "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" (PMEDICINE-D-20-01625R2) for consideration at PLOS Medicine.

Your paper was evaluated by a senior editor and discussed among all the editors here. It was also discussed with an academic editor with relevant expertise, and sent to independent reviewers, including a statistical reviewer. The reviews are appended at the bottom of this email and any accompanying reviewer attachments can be seen via the link below:

[LINK]

In light of these reviews, I am afraid that we will not be able to accept the manuscript for publication in the journal in its current form, but we would like to consider a revised version that addresses the reviewers' and editors' comments. Obviously we cannot make any decision about publication until we have seen the revised manuscript.

In revising the manuscript for further consideration, your revisions should address the specific points made by each reviewer and the editors. Regarding comments from reviewer 2, we ask that you include additional covariates in your model/sensitivity analyses to alleviate the concerns noted by the reviewer or clearly outline the assumptions made and their limitations.

Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments, the changes you have made in the manuscript, and include either an excerpt of the revised text or the location (eg: page and line number) where each change can be found. Please submit a clean version of the paper as the main article file; a version with changes marked should be uploaded as a marked up manuscript.

In addition, we request that you upload any figures associated with your paper as individual TIF or EPS files with 300dpi resolution at resubmission; please read our figure guidelines for more information on our requirements: http://journals.plos.org/plosmedicine/s/figures. While revising your submission, please upload your figure files to the PACE digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at PLOSMedicine@plos.org.

We expect to receive your revised manuscript by Nov 16 2020 11:59PM. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

We ask every co-author listed on the manuscript to fill in a contributing author statement, making sure to declare all competing interests. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. If new competing interests are declared later in the revision process, this may also hold up the submission. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT. You can see our competing interests policy here: http://journals.plos.org/plosmedicine/s/competing-interests.

Please use the following link to submit the revised manuscript:

https://www.editorialmanager.com/pmedicine/

Your article can be found in the "Submissions Needing Revision" folder.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see http://journals.plos.org/plosmedicine/s/submission-guidelines#loc-methods.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

We look forward to receiving your revised manuscript.

Sincerely,

Adya Misra, PhD

Senior Editor

PLOS Medicine

plosmedicine.org

-----------------------------------------------------------

Requests from the editors:

Comments from the reviewers:

Reviewer #1: The authors have addressed my points. I still think it is a shame that we do not know whether there is a threshold below which further BP reduction is pointless but their data shows that this is only a minority interest.

Michael Dewey

Reviewer #2: Dear Editors of PLOS Medicine,

It is with great interest that I read the revised version of "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" by Prof. Rahimi et al.

Firstly, I must emphasize that I think this meta-analysis is of huge importance clinically. Before, guidelines have only had the ACITVE-I trial and observational data to lean on, giving advice on BP lowering in atrial fibrillation. Thus, the current BPLTTC analysis will have huge impact, and therefore it needs to be great. For simplicity, I will follow the same structure as in my previous set of comments.

1) Ok, so it builds on a systematic literature search (not the same as systematic review). This should be reported in the manuscript (or appendix), not only referred to the published protocol. The authors should consider a PRISMA flowchart like the one in the protocol, but with an additional level below the 100 trials eligible for consideration, explaining what they explained in text in their response. Also, the funnel plot they use as an argument against acquisition bias should be added to the appendix. A systematic review needs to be 100% transparent.

2) I´m very happy that the authors decided to perform risk of bias assessments. However, these are not included in the appendix submitted. It does sound strange, though, that all trials were judged to be at low risk of bias. For example, randomization in the CAPPP trial is known to have failed, as pointed out elegantly by Richard Peto in a letter to the editor few months after the original publication (https://doi.org/10.1016/S0140-6736(05)75340-X). In EWPHE, 36% of participants stopped the double-blind phase early; 15% of participants were lost to follow-up for non-mortality outcomes. The number of participants lost to follow-up widely exceeded the number of participants with cerebrovascular events (all in the original Lancet publication). How do the authors motivate "low risk of bias" in these circumstances? I really hope I´ll get to see the full risk of bias table, including judgements for each domain, in a future submission.

3) It is very unfortunate that HF data has not been shared since the HF is such an important confounder in BP lowering trials. The authors have done what they can with this comment, although the sensitivity analysis presented in this response must also be added to the appendix.

4) This is still my main concern, which I seem to be sharing with reviewer 1 (statistical reviewer). Of course, it is possible to include trials without AF participants in the statistical model, but including them will inevitably make AF and non-AF participants in the meta-analysis more different, as I explained in my previous comment. The authors state that this is accounted for, because the model assumes different baseline hazards for each trial, and because treatment arm, trial-level BP differences between treatment arms, and treatment-BP difference interaction, were included as covariates. For such a model to be valid, baseline hazard and BP difference would have to be the only two determinants of treatment effect beyond AF status, under study here. This implicitly assumes that no other trial or patient characteristics are important per se; everything is summarized in the baseline hazard function. This is a quite strong assumption, which, although the authors have argued for it previously, is not agreed upon by all in the hypertension community. For example, Thomopoulos et al (DOI:10.1097/HJH.0000000000001276 ) have found differences in treatment effect between people with and without diabetes, and Brunström et al have found differences between different baseline BP levels in primary prevention, and differences between primary and secondary preventive participants at low baseline BPs (doi:10.1001/jamainternmed.2017.6015). These meta-analyses are of course trial-level analyses, with potential for ecological bias, but nonetheless they are potential arguments for why other things (like DM, baseline BP, and previous CVD), beyond baseline hazard and BP difference, would be important to consider in a model accounting for differences between AF and non-AF participants.

Based on the difficulties described above, which would be much less severe had non-AF trials been excluded, I think the main analysis should be restricted to trials including both AF and non-AF participants. I completely disagree with the authors´ statement that their one-stage model "did not lead to bias, but improved precision". In my view, that improved precision is false because it comes from trials not including people with the condition under study. This, in turn, is very important because the evidence for AF participants is in fact weaker than suggested by this study.

If the authors persist including non-AF trials, and the editors chose to accept this (against my recommendation), I would recommend including more covariates (at least the ones mentioned above) in their model to fully account for potential differences in treatment effect between AF and non-AF participants. If the authors persist with the same model, and the editors chose to accept this (against my recommendation), they need to be very explicit about the assumptions that comes with that model, and discuss this under the limitations section.

5) Again, the argument that population/setting is accounted for by different baseline hazard functions depends on the assumption that no trial or population characteristics interact with the treatment effect. This, quite simplistic, view is also reflected in the argument concerning fixed- and random-effects model. However, I do think that the sensitivity analysis using both types of models is reassuring, as expected when statistical heterogeneity is low. Results from the I2-analyses and the sensitivity analysis should be presented to the readers in the appendix and commented in the article.

6) Ok, needs to be included in the appendix.

7) Great, but the conclusion in the main article needs to be toned down as well. "…even when baseline BP is below recommended treatment thresholds" should be removed or rephrased. Although the analysis >/< 140 mm Hg did not find evidence for an interaction, the analysis had low power and the results in each group was not significant on its own. Phrasing in abstract "no evidence that treatment effects varied according to baseline systolic BP or drug class" is more correct.

One additional minor note is that the Ettehad reference now appears twice.

Reviewer #3: No additional comments

Any attachments provided with reviews can be seen via the following link:

[LINK]

Decision Letter 3

Artur Arikainen

19 Jan 2021

Dear Dr. Rahimi,

Thank you very much for re-submitting your manuscript "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" (PMEDICINE-D-20-01625R3) for review by PLOS Medicine.

I have discussed the paper with my colleagues and the academic editor, and it was also seen again by one of the reviewers. I am pleased to say that provided the remaining editorial and production issues are dealt with we are planning to accept the paper for publication in the journal.

The remaining issues that need to be addressed are listed at the end of this email. Any accompanying reviewer attachments can be seen via the link below. Please take these into account before resubmitting your manuscript:

[LINK]

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

In revising the manuscript for further consideration here, please ensure you address the specific points made by each reviewer and the editors. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments and the changes you have made in the manuscript. Please submit a clean version of the paper as the main article file. A version with changes marked must also be uploaded as a marked up manuscript file.

Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. If you haven't already, we ask that you provide a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract.

We expect to receive your revised manuscript within 1 week. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

We ask every co-author listed on the manuscript to fill in a contributing author statement. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

Please note, when your manuscript is accepted, an uncorrected proof of your manuscript will be published online ahead of the final version, unless you've already opted out via the online submission form. If, for any reason, you do not want an earlier version of your manuscript published online or are unsure if you have already indicated as such, please let the journal staff know immediately at plosmedicine@plos.org.

If you have any questions in the meantime, please contact me or the journal staff on plosmedicine@plos.org.  

We look forward to receiving the revised manuscript by Jan 26 2021 11:59PM.   

Sincerely,

Artur Arikainen,

Associate Editor 

PLOS Medicine

plosmedicine.org

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Requests from Editors:

1. Please address reviewer #2’s final comment regarding HF patients at baseline.

2. Financial Disclosure: Please write in full sentences and also add “The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”; or explain otherwise.

3. Competing Interests: Please update to use our standard text: “KR is an Academic Editor on PLOS Medicine's editorial board."

4. Data Availability Statement: Since the data are not freely available, please describe/reiterate briefly the ethical, legal, or contractual restriction that prevents you from sharing it. Please also include an appropriate contact (web or email address) for inquiries (note: this cannot be a study author).

5. Abstract:

a. Line 29: No need to define BP once more.

b. Please report your abstract according to PRISMA for abstracts, following the PLOS Medicine abstract structure (Background, Methods and Findings, Conclusions) http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001419. Specifically, please describe how trials were identified/searched for, including database names, search date(s), inclusion criteria, method of quality/bias assessment.

c. Please mention a summary of trial numbers by country/region, and overall study quality/bias.

d. Please include p values, and also quantify your results further for these data: “Meta-regression showed that relative risk reductions were proportional to trial-level intensity of BP lowering in patients with and without AF at baseline.”

e. In the limitations, "difficulty in ascertaining AF cases" could be made more explicit (i.e., did the original investigators have heterogeneous criteria for AF, or did the authors of the present paper have difficulty extracting the information from study reports, or both).

f. Conclusions: Please begin with “In this meta-analysis, we found that…” (or similar)

6. Please move citations to before punctuation, eg: “…[1,2].”

7. Methods: Please mention that separate ethical approval was not required for your study.

8. Results and Figures: Please present p values for comparisons.

9. Lines 346-349: Please delete Funding information from here.

10. Please delete “(London, England)” from the journal name for Lancet references.

11. Please upload each item of Supplementary Information as a separate file, with no tracked changes. Please then include a citation to the supplementary methods in the main Methods section.

12. Please move S1 Figure to be a main Figure.

13. Please report your SR/MA according to the PRISMA guidelines provided at the EQUATOR site: http://www.equator-network.org/reporting-guidelines/prisma/

Please provide the completed PRISMA checklist. When completing the checklist, please use section and paragraph numbers, rather than page numbers. Please also add the following statement, or similar, to the Methods: "This study is reported as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline (S1 Checklist)."

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Comments from Reviewers:

Reviewer #2: Thank you for the opportunity to review this third version of the BPLTTC manuscript on antihypertensive treatment in patients with atrial fibrillation, with Prof Rahimi as the corresponding author.

Since the previous version, the manuscript has improved significantly. The authors have carefully addressed all my comments. They have extracted additional data (heart failure data from the ACTIVE-I trial), of crucial importance to ascertain the validity of the study findings, and they have performed several additional analyses, reported in the supplement and commented in the main text, with reassuring results. Also, the methods are more transparent, as the supplementary text has been expanded. The authors should be commended for their efforts.

Regarding point 4 in the previous set of comments, where we seem to disagree on the optimal analytical approach, the authors argue for leaving out several covariates of possible interest, because the aim was, quote: "to answer the question of whether a typical patient with AF as included in the trials would benefit similarly from BP lowering treatment as someone without AF. By contrast, the proposed approach by the reviewer is to ensure that patients with AF and no-AF are as similar as possible, which presumably will help understand the independent effect of AF on effect modification". In the methods section, paragraph on statistical analysis, they write, quote "Our main analyses aimed to address four questions: (q1) whether AF status at baseline modifies treatment effects…". Thus, it seems to me we agree that the adjusted analyses would be meaningful to answer the first research question. I see no real problem in using different primary models to address different research questions, and the authors could consider elevating this in relation to q1 in the results.

One additional comment is that it is stated on row 274 that patients with HF at baseline were excluded from all studies. However, there is also a sensitivity analysis, excluding HF patients from ACTIVE-I. This should be clarified.

Finally, I would like to congratulate the authors on an interesting and important paper.

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Any attachments provided with reviews can be seen via the following link:

[LINK]

Decision Letter 4

Caitlin Moyer

24 Feb 2021

Dear Dr. Rahimi,

Thank you very much for re-submitting your manuscript "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" (PMEDICINE-D-20-01625R4) for review by PLOS Medicine.

I apologize for the delay responding to your recent inquiry, and thank you for submitting the revised version addressing the editor and reviewer comments. There are a few remaining editorial issues to address, but provided these are resolved and production issues are dealt with we are planning to accept the paper for publication in the journal.

The remaining issues that need to be addressed are listed at the end of this email. Any accompanying reviewer attachments can be seen via the link below. Please take these into account before resubmitting your manuscript:

[LINK]

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

In revising the manuscript for further consideration here, please ensure you address the specific points made by each reviewer and the editors. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments and the changes you have made in the manuscript. Please submit a clean version of the paper as the main article file. A version with changes marked must also be uploaded as a marked up manuscript file.

Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. If you haven't already, we ask that you provide a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract.

We expect to receive your revised manuscript within 1 week. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

We ask every co-author listed on the manuscript to fill in a contributing author statement. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript.

Please note, when your manuscript is accepted, an uncorrected proof of your manuscript will be published online ahead of the final version, unless you've already opted out via the online submission form. If, for any reason, you do not want an earlier version of your manuscript published online or are unsure if you have already indicated as such, please let the journal staff know immediately at plosmedicine@plos.org.

If you have any questions in the meantime, please contact me or the journal staff on plosmedicine@plos.org.  

We look forward to receiving the revised manuscript by Mar 03 2021 11:59PM.   

Sincerely,

Caitlin Moyer, Ph.D.

Associate Editor 

PLOS Medicine

plosmedicine.org

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Requests from Editors:

1. Similarity with published abstract: It appears that there is some overlap between the content of the manuscript and your published abstract.

Regarding the text overlap, please slightly reword any directly replicated text, if possible, to avoid copyright issues.

For example:

In the abstract: "The hazard ratio for major cardiovascular events was 0.91 in patients with AF (95% confidence interval 0.83 to 1.00) and 0.91 without AF (95% confidence interval 0.88 to 0.93) for each 5-mmHg reduction in systolic BP, with no difference between subgroups. In patients with AF, there was no evidence that treatment effects varied according to baseline systolic BP or drug class."

The final sentence of the Discussion/Conclusion: "Guidelines should be updated to give clear recommendations for pharmacological BP lowering for prevention of cardiovascular events in patients with AF."

In addition, Figure 4 is reproduced from the published abstract: (https://doi.org/10.1093/ehjci/ehaa946.0672). If you would like to include the figure in the manuscript, please contact OUP to obtain their agreement to it being published under our license. An alternative would be to remove the figure and present the data in a different format (e.g. as a table).

2. Data Availability Statement: Thank you for your response "We have now added the data availability statement as requested and explained how the interested authors could ask for BPLTTC dataset." Please update the data availability statement of the manuscript submission form with the information provided on Page 16 Lines 363-366.

3. Please remove the highlighting in the final "clean" version submitted.

4. Methods: Page 6: Lines 126-127: Please provide a reference to the supporting information file for the protocol (e.g. S1_Protocol).

5. Discussion: Line 302: Please revise this sentence, as there may be a word missing here: "...ideal SBP target for prevention of cardiovascular was found..."

6. Page 16: Please remove the Financial Disclosure and Data Availability Statement sections from the main text, and ensure the information is entered in the appropriate section of the manuscript submission form.

7. References: Please double check the formatting of references, using NLM journal title abbreviations where appropriate (e.g. JAMA Intern Med instead of JAMA Internal Medicine). Please use the "Vancouver" style for reference formatting, and see our website for other reference guidelines: https://journals.plos.org/plosmedicine/s/submission-guidelines#loc-references

Any attachments provided with reviews can be seen via the following link:

[LINK]

Decision Letter 5

Caitlin Moyer

25 Mar 2021

Dear Dr Rahimi, 

On behalf of my colleagues and the Academic Editor, Gregory Lip, I am pleased to inform you that we have agreed to publish your manuscript "Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis" (PMEDICINE-D-20-01625R5) in PLOS Medicine.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. Please be aware that it may take several days for you to receive this email; during this time no action is required by you. Once you have received these formatting requests, please note that your manuscript will not be scheduled for publication until you have made the required changes.

In the meantime, please log into Editorial Manager at http://www.editorialmanager.com/pmedicine/, click the "Update My Information" link at the top of the page, and update your user information to ensure an efficient production process. 

PRESS

We frequently collaborate with press offices. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximise its impact. If the press office is planning to promote your findings, we would be grateful if they could coordinate with medicinepress@plos.org. If you have not yet opted out of the early version process, we ask that you notify us immediately of any press plans so that we may do so on your behalf.

We also ask that you take this opportunity to read our Embargo Policy regarding the discussion, promotion and media coverage of work that is yet to be published by PLOS. As your manuscript is not yet published, it is bound by the conditions of our Embargo Policy. Please be aware that this policy is in place both to ensure that any press coverage of your article is fully substantiated and to provide a direct link between such coverage and the published work. For full details of our Embargo Policy, please visit http://www.plos.org/about/media-inquiries/embargo-policy/.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols

Thank you again for submitting to PLOS Medicine. We look forward to publishing your paper. 

Sincerely, 

Caitlin Moyer, Ph.D. 

Associate Editor 

PLOS Medicine

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 Fig. Funnel plot for assessment of publication (acquisition) bias on the effect of blood pressure reduction and risk of major cardiovascular event.

    (DOCX)

    S2 Fig. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by presence of atrial fibrillation at baseline and adjusted for a 3.7-mm Hg systolic blood pressure reduction.

    (DOCX)

    S1 Table. Difference in systolic blood pressure reduction between arms for each trial.

    (DOCX)

    S2 Table. Assessment of risk of bias.

    (DOCX)

    S3 Table. Number of trials available for drug class comparisons.

    (DOCX)

    S4 Table. Treatment comparisons for subgroup analyses by drug class.

    (DOCX)

    S5 Table. Summary of included trials.

    (DOCX)

    S6 Table. Baseline characteristics of the participants included in atrial fibrillation meta-analyses stratified by trial.

    (DOCX)

    S7 Table. Sensitivity analyses including only trials that included patients with and without atrial fibrillation at baseline.

    (DOCX)

    S8 Table. Fixed and random effects two-stage meta-analyses.

    (DOCX)

    S9 Table. Unadjusted effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline.

    (DOCX)

    S10 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, excluding the patients with the diagnosis of heart failure at baseline in ACTIVE-I trial.

    (DOCX)

    S11 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, after adjustment for baseline systolic blood pressure, cardiovascular disease status, and diabetes status at baseline.

    (DOCX)

    S12 Table. Sensitivity analysis for the effect of blood pressure-lowering treatment on primary and secondary outcomes, stratified by the presence of atrial fibrillation at baseline, excluding the trials with moderate risk of bias.

    (DOCX)

    S1 Methods

    (DOCX)

    S1 PRISMA Checklist

    (DOCX)

    S1 Protocol

    (DOCX)

    Attachment

    Submitted filename: Answers_reviewers_PLOS_final.docx

    Attachment

    Submitted filename: AF reviewer comment_Final_KR.docx

    Attachment

    Submitted filename: Response.docx

    Attachment

    Submitted filename: Requests from Editors.docx

    Data Availability Statement

    The governance of BPLTTC and policies on data access and sharing policies are described elsewhere (Rahimi K, et al. BMJ Open 2019;9:e028698). Our data sharing agreements with our collaborators limit us from sharing the original data to third parties. However, a governance framework exists for collaborative projects with external research investigators. For further queries, please check www.bplttc.org for our contact details.


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