Skip to main content
PLOS One logoLink to PLOS One
. 2023 Jun 8;18(6):e0286307. doi: 10.1371/journal.pone.0286307

Specialized heart failure clinics versus primary care: Extended registry-based follow-up of the NorthStar trial

Morten Malmborg 1,*, Ali Assad Turky Al-Kahwa 2, Lars Kober 3,4, Christian Torp-Pedersen 5,6, Jawad H Butt 3, Deewa Zahir 2, Christian D Tuxen 7, Mikael K Poulsen 8, Christian Madelaire 2, Emil Fosbol 3, Gunnar Gislason 1,2,4,9, Per Hildebrandt 10,11, Charlotte Andersson 12, Finn Gustafsson 3,4, Morten Schou 2
Editor: Giuseppe Gargiulo13
PMCID: PMC10249840  PMID: 37289772

Abstract

Background

Whether continued follow-up in specialized heart failure (HF) clinics after optimization of guideline-directed therapy improves long-term outcomes in patients with HF with reduced ejection fraction (HFrEF) is unknown.

Methods and results

921 medically optimized HFrEF patients enrolled in the NorthStar study were randomly assigned to follow up in a specialized HF clinic or primary care and followed for 10 years using Danish nationwide registries. The primary outcome was a composite of HF hospitalization or cardiovascular death. We further assessed the 5-year adherence to prescribed neurohormonal blockade in 5-year survivors. At enrollment, the median age was 69 years, 24,7% were females, and the median NT-proBNP was 1139 pg/ml. During a median follow-up time of 4.1 (Q1-Q3 1.5–10.0) years, the primary outcome occurred in 321 patients (69.8%) randomized to follow-up in specialized HF clinics and 325 patients (70.5%) randomized to follow-up in primary care. The rate of the primary outcome, its individual components, and all-cause death did not differ between groups (primary outcome, hazard ratio 0.96 [95% CI, 0.82–1.12]; cardiovascular death, 1.00 [0.81–1.24]; HF hospitalization, 0.97 [0.82–1.14]; all-cause death, 1.00 [0.83–1.20]). In 5-year survivors (N = 660), the 5-year adherence did not differ between groups for angiotensin-converting enzyme inhibitors (p = 0.78), beta-blockers (p = 0.74), or mineralocorticoid receptor antagonists (p = 0.47).

Conclusions

HFrEF patients on optimal medical therapy did not benefit from continued follow-up in a specialized HF clinic after initial optimization. Development and implementation of new monitoring strategies are needed.

Introduction

It is well-established that in patients with heart failure (HF) with reduced left ventricular ejection fraction (HFrEF), an integrated HF clinic program including implementation of disease-modifying drugs and devices, patient education in self-care, and referral for physical training improves long-term clinical outcomes [1]. However, after the completion of such a program, it is unclear whether patients should be followed in specialized HF clinics, by their general practitioner only, or both [2]. The decision may depend on the patient’s risk of deterioration and the organization of the healthcare system in the respective countries.

In The NorthStar study, patients with HFrEF receiving optimal medical therapy did not benefit from continued follow-up in a specialized HF clinic compared with follow-up in primary care during a median follow-up of 2.5 years, even in high-risk patients, defined as patients with an N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) ≥1000 pg/ml [2]. These initial results were in accordance with a pharmacy intervention study in primary care in the United Kingdom [3] and an HF clinic intervention trial (COACH 2) from The Netherlands [4]. However, since the NorthStar study was conducted, the prognosis of HFrEF patients has improved, and long-term data evaluating the organization of care are lacking. During such a long period new drugs and devices may be developed and adherence to HF guideline therapy may decline in case of lack of continued focus on this area.

Therefore, in a posthoc analysis of the NorthStar study, we evaluated the effect of extended follow-up in a specialized HF clinic, compared with follow-up in the primary care, on the long-term risk of HF hospitalization and cardiovascular death, and adherence to the neurohormonal blockade, in medically optimized HFrEF patients.

Methods

Study design

This is an extended registry-based follow-up study of patients randomized in The NorthStar Study. The NorthStar Study was an investigator-initiated, multi-center, randomized, open-labeled, blinded endpoint trial (PROBE) [2, 5]. HFrEF patients from 18 out of 40 HF clinics (HFC) in Denmark were educated in self-care and optimized in medical therapy according to contemporary guidelines in HFC. Next, patients were randomized to either continued follow-up in a specialized HFC or discharge to primary care (PC). Patients allocated to usual care arranged an individual follow-up program with their general practitioner, whereas patients allocated to an extended follow-up in the HFC with visits at 1–3-month intervals, in which adherence to treatment, symptoms, risk factors, and comorbidities were monitored and controlled. In the trial, the median follow-up period was 2.5 years (up to 5 years of follow-up) and the intervention did not affect the primary outcome (the composite of death from any cause or admission for a protocol-specified CV cause), cardiovascular hospitalization, or death of any cause [2].

Data sources

All residents in Denmark receive a unique and permanent civil registration number at birth or immigration that enables individual-level linkage between nationwide registries and the electronic case report from the NorthStar study. Baseline data including demographic variables, clinical biochemistry, left ventricular ejection fraction, and NT-proBNP levels were available from the trial’s electronic case report form. For this extended follow-up analysis, we further obtained data from 1) the Danish Civil Registration System registry (sex, date of birth, immigration, emigration, and vital status), 2) the Danish National Patient Registry (discharge diagnoses coded according to the International Classification of Diseases (ICD)-10 since 1994), and 3) the Danish National Causes of Death Registry (date of death and underlying causes of death from death certificates). All registries have been validated previously [68].

Study population

Patients with HFrEF (left ventricular ejection fraction ≤0.45) were included between 2005 to 2009 from 18 out of 40 public HF clinics in Denmark according to the inclusion and exclusion criteria (S1 Methods). Patients were educated in self-care and HF disease and were on optimal medical therapy at the study baseline. Up-titration of renin-angiotensin-system inhibitors (RASi), beta-blockers (BB), and mineralocorticoid receptor antagonists (MRA) was performed according to international guidelines, and devices were implanted if considered indicated [9]. At the time of randomization, patients with a left ventricular ejection fraction ≤ 0.45 were considered to have HFrEF in Denmark.

Study outcomes

The primary outcome was the composite of HF hospitalization (defined as an overnight stay with one of the following hospital discharge codes for HF: ICD-10-codes I110, I130, I132, I420, I426-429, I500-503, I508-509) or cardiovascular (CV) death as the underlying cause of death (ICD-10-codes I00-99), whichever came first. The secondary outcomes were the components of the primary outcome and death of any cause. A discharge diagnosis of HF has been validated with a positive predictive value of 81% [10].

Dose and treatment duration

The National Prescription Registry does not include information on the prescribed daily dosage of the medication, but rather the date of dispensing, strength, and quantity. Among 5-year survivors, we created an algorithm, in which a minimum, maximum, and typical daily dosage of used medication was defined for each RASi, BB, and MRA dispensed between 1 January 2004 and 31 December 2018. Based on methods described previously [11], we calculated whether patients at any time had tablets available or not. We defined a patient as receiving treatment if tablets were available.

Statistical analyses

All individuals were followed from the date of randomization until the first event of interest, death, or emigration, whichever came first.

The baseline characteristics from Schou et al. [2] have been presented in the study (Table 1). In 5-year survivors, we estimated the prevalence of patients with an implantable cardioverter-defibrillator (ICD-10 codes BFCB) and a cardiac resynchronization therapy device (ICD-10 codes BFCA4-6, BFCA21, BFCB03, BFCB21). In the main analysis, we estimated the absolute 10-year risk of the primary and secondary endpoints using the Aalen-Johansen estimator, which incorporates competing risks of death. For the primary outcome and CV death, the competing risk was non-CV death, and all-cause death for the HF hospitalization outcome. We used a Cox regression model to calculate hazard ratios with 95% confidence intervals of the primary and secondary outcomes comparing the PC and HFC groups. In subgroup analyses, we used a Cox regression model to calculate the hazard ratio of the primary outcome comparing the PC and HFC groups in subgroups of risk factors (NT-proBNP ≥1,000/<1,000, age ≥70/<70, left ventricular ejection fraction <30/≥30, The New York Heart Association functional class 3/1-2, atrial fibrillation yes/no, estimated glomerular filtration rate <60/≥60, anemia yes/no (yes: <7.4 mmol/L for women, <8.1 mmol/L for men), hyponatremia yes/no, Minnesota score ≥25/<25, previous myocardial infarction yes/no, diabetes yes/no, use of aldosterone antagonists yes/no, use of ≥80 mg furosemide/24h yes/no).

Table 1. Population characteristics at the time of randomization.

Characteristics Heart failure clinic (n = 460) Primary care (n = 460)
Demographic 
 Age (years, median)  69 (47–86)  69 (43–86) 
 Female (sex)  106 (23)  122 (27) 
Clinical 
 NYHA class I–II  411 (89)  410 (88) 
 Blood pressure (mmHg) 
  Systolic  127 (90–177)  124 (90–166) 
  Diastolic  75 (50–92)  73 (50–100) 
 Heart rate (b.p.m.)  65 (49–92)  66 (48–95) 
 Left ventricular ejection fraction  0.32 (0.15–0.45)  0.30 (0.15–0.45) 
 Atrial fibrillation  152 (33)  146 (32) 
 LBBB in non-paced ECG  76 (19)  92 (23) 
 Body mass index (kg/m2 26 (20–37)  26 (19–40) 
 Heart failure etiology 
  Non-ischaemic  188 (41)  193 (43) 
  Ischaemic  268 (59)  255 (57) 
 Minnesota Living with Heart Failure Questionnaire Score  25 (0–75)  22 (0–73) 
 Duration of the basic HFC program, months  9 (2–61)  9 (2–63) 
Medical history 
 Admission within 12 months  188 (41)  207 (45) 
 Hypertension  193 (43)  183 (40) 
 Myocardial infarction  238 (52)  219 (48) 
 Previous PCI/CABG  190 (41)  188 (41) 
 Stroke or TCI  53 (12)  56 (12) 
 Peripheral vascular disease  37 (8)  42 (9) 
 Stable angina pectoris  36 (8)  41 (9) 
 Diabetes  85 (18)  85 (18) 
 Chronic obstructive pulmonary disease  62 (13)  73 (16) 
Laboratory tests 
 NT-proBNP (pg/mL)  793 (63–6720)  803 (58–7517) 
 Haemoglobin (mmol/L)  8.6 (6.6–10.3)  8.5 (6.70–10.4) 
 Anemia  94 (21)  102 (23) 
 Sodium (mmol/L)  140 (131–145)  140 (130–145) 
 Hyponatremia  76 (17)  72 (16) 
 Potassium (mmol/L)  4.3 (3.5–5.1)  4.3 (3.5–5.2) 
 Creatinine (μmol/L)  88 (62–185)  91 (62–193) 
 Estimated GFRMDRD –mL/min/1.73 m2  69 (30–118)  66 (30–121) 
 Estimated GFRMDRD ≤ 60 mL/min/1.73 m2  152 (33)  179 (39) 
Medication 
 ACE-I/ARB  392 (85)  408 (89) 
 ACE-I/ARB, max. target dose  306 (66)  313 (68) 
 BB  388 (84)  391 (85) 
 BB, at the target dose  243 (53)  226 (49) 
 MRA/ARA  143 (31)  153 (33) 
 Loop diuretics  259 (56)  272 (59) 
 Furosemide doses (mg/24 h)  40 (0–240)  40 (0–290) 
 Thiazide  42 (9)  30 (7) 
 Digoxin  71 (15)  66 (14) 
 Lipid-lowering agents  296 (64)  303 (66) 
 Antiplatelets  322 (70)  338 (73) 
 Anticoagulants  142 (31)  117 (25) 
 Nitrates  29 (6)  40 (9) 
 Gout medication  35 (8)  26 (6) 
 Antidepressants  32 (7)  26 (6) 
 Amiodarone  14 (3)  17 (4) 
Device therapy 
 ICD  42 (9)  32 (7) 
 CRT  7 (2)  7 (2) 

Abbreviations: NYHA class, New York Heart Association; LBBB, left bundle branch block; HFC, heart failure clinic; PCI, percutaneous intervention; CABG, coronary artery bypass graft; TCI, transitory cerebral ischemia; NT-proBNP, amino-terminal-pro-brain-natriuretic-peptide; estimated GFRMDRD, estimated glomerular filtration rate (modification of diet in renal disease formula); ACE-I, angiotensin-converting enzyme inhibitors; ARB, angiotensin receptor blocker; BB, beta-blocker; ARA, aldosterone receptor antagonist; MRA, mineralocorticoid receptor antagonists; ICD, implantable cardiac defibrillator; CRT, cardiac resynchronization therapy. aAnaemia was defined according to WHO: <7.4 mmol/L for females and <8.1 mmol/L for males. hyponatremia was defined as plasma sodium <136 mmol/L.

In supplementary analyses, we included an analysis comparing groups based on the number of HF rehospitalizations. In 2-year survivors, patients were followed from 2 years following randomization until the event of interest, death, or 10 years following randomization. The absolute 8-year risk of the primary and secondary endpoints was estimated in groups defined by the number of HF hospitalizations (0, 1, or >1) within the first 2 years following randomization using the Aalen-Johansen estimator, incorporating the competing risks of death (Kaplan-Meier for all-cause death). We used a Cox regression model adjusted for numbers of prior HF hospitalizations to calculate hazard ratios with 95% confidence intervals of the primary and secondary outcomes comparing the PC and HFC groups. To analyze the main exposure in groups by the number of prior HF hospitalization, the interaction between the main exposure (PC vs HFC) and the number of prior HF hospitalizations was analyzed in the same Cox models.

Lastly, we used consecutive claimed prescriptions to calculate the drug adherence level as a proportion of days covered (PDC) for RASi, BB, and MRA among 5-year survivors. PDC was calculated for each drug group separately as days exposed to the medication within the five years following randomization (PDC = days covered / 365.25*5). Zero one inflated beta-regression was used to calculate differences in means of PDC for each drug group between the PC and HF clinic groups.

The significance level for all analyses was set to 5% (two-sided). All statistical analyses were conducted using R version 3.6.1 [12].

Ethics

The trial was approved by the Danish Ethics Committee (KF 01/2724936), and all the patients provided written informed consent. Retrospective register studies do not need ethical approval in Denmark. The extended register-based follow-up was approved by the Danish Data Protection Agency (Approval number P-2019-396).

Results

A total of 6,180 patients had at least one visit to one of the HFCs during the randomization period, of which 1,640 fulfilled the criteria for stability and were eligible (S1 Fig). 54 patients were excluded due to the presence of exclusion criteria, 103 declined to participate in a scientific project, 107 wanted to be followed by their general practitioner, 256 patients had an NT-proBNP <1000 pg/mL after allocation in this group was completed, and 199 consenting patients were randomly assigned for a parallel study. The remaining 921 patients were enrolled, of which 461 were randomly assigned to undergo follow-up in the HFC, and 460 to receive usual care. The baseline characteristics of the patients were similar between the two groups (Table 1). On average, all patients had been followed already for 9 (2–63) months in the HFC at the time of randomization.

After 5 years of follow-up, 335 (72.7%) patients in the HFC group and 325 (70.7%) patients in the PC group were still alive. At 5 years following randomization, 64 (19.1%) and 62 (19.1%) patients had an implantable cardioverter-defibrillator in the HFC and PC group, respectively (chisq test p-value = 1.00), and 25 (7.5%) and 30 (9.2%) patients had a cardiac resynchronization therapy device in the HFC and PC group, respectively (chisq test p-value = 0.50).

10-year risks of primary and secondary outcomes

After 10 years of follow-up, CV death or an HF hospitalization occurred in 321 patients from the HFC group and 325 patients from the PC group, corresponding to a 10-year risk of 70.5% (CI 66.0–74.4) and 69.8% (CI 65.3–73.7), respectively (Fig 1). We observed no difference between the PC and HFC groups (Hazard ratio 0.96 (0.82–1.12), p-value 0.59; Fig 1). Similarly, we observed no difference in the absolute 10-year risk of all-cause death (HFC: n = 238, 51.7% [CI 46.9–56.1]; PC: n = 233, 50.7% [CI 45.9–55.1]), CV death (HFC: n = 174, 40.4% [CI 35.5–44.9]; PC: n = 171, 40.7% [CI 35.7–45.3]) and HF hospitalization (HFC: n = 297, 69.2% [CI 64.3–73.4]; PC: n = 293, 68.6% [CI 45.9–72.9]) (Fig 1). Among the most common causes of rehospitalization during follow-up, a rehospitalization for HF was the most common cause of any rehospitalization (S1 Table).

Fig 1. 10-year absolute risk of all-cause death, cardiovascular death, discharge for heart failure, and cardiovascular death or discharge for heart failure.

Fig 1

Abbreviations: PC = primary care, HFC = heart failure clinic, HR = hazard ratio.

Subgroup analyses

Patients randomized to follow-up in HF clinics did not have a significantly different risk of the primary composite outcome in any of the predefined subgroups compared with those randomized to follow-up in primary care (Fig 2). Of note, atrial fibrillation was non-significantly associated with a higher hazard rate in the HFC group compared to the PC group (HR 0.78 [0.60–1.02], p = 0.07). However, due to a low number of patients and outcomes, the non-significant result may be due to power issues.

Fig 2. Occurrence of cardiovascular death or discharge for heart failure in subgroups.

Fig 2

Abbreviations: PC = primary care, HFC = heart failure clinic, n = the number of events of the primary outcome, N = the number of patients in the PC or HFC group, CI = confidence interval, NT_proBNP = N-terminal Pro-B-Type Natriuretic Peptide, LVEF = Left ventricular ejection fraction, NYHA = New York Heart Association functional classification, AF = atrial fibrillation, eGFR = estimated glomerular filtration rate, MI = myocardial infarction.

Supplementary analyses

At 2 years following randomization, 415 (HF = 0, 304 patients; HF = 1, 64 patients; HF >1, 47 patients) and 408 patients (HF = 0, 317 patients; HF = 1, 46 patients; HF >1, 45 patients) were alive in the HFC and PC group, respectively. We observed that the number of prior HF hospitalizations was strongly associated with the primary and secondary outcomes in both the PC and HFC groups (S2 Fig and S2 Table). In the interaction analyses, no differences were observed between the PC and HFC groups in subgroups of the number of HF hospitalization regardless of the outcome of interest (S2 Table). However, since the numbers of both patients and outcomes were low, particularly in the groups of patients with prior HF hospitalizations within the first 2 years following randomization, these results should be interpreted with caution.

Coverage and drug adherence in 5-year survivors

In 5-year survivors, a low proportion had not been covered by RASi (HFC: 3.0%; PC: 2.2%) and BB (HFC: 2.1%; PC: 3.1%) during the 5 years of follow-up, and among individuals covered with RASi or BB the PDC-level for both drugs was high (Fig 3). In contrast, approximately half of the patients had not been covered by MRA (HFC: 51.9%; PC: 52.0%). We observed no difference in means of PDC between the HFC and the PC group (RASi: p = 0.78; BB: p = 0.74; MRA: p = 0.47).

Fig 3. Adherence to mineralocorticoid receptor antagonists, beta-blockers, and renin-angiotensin system inhibitors in 5-year survivors during the first 5 years of follow-up.

Fig 3

Abbreviations: MRA = mineralocorticoid receptor antagonists, BB = beta blocker, RASi = renin-angiotensin receptor system inhibitors, PC = primary care, HFC = heart failure clinic.

Discussion

Main findings

We observed that HFrEF patients on optimal medical therapy did not benefit from additional years of extended follow-up in a specialized HF clinic. The risk of relevant HF endpoints and adherence to neurohormonal blockade did not differ between patients followed in an HFC compared to PC. Our results underscore the need for the development of improved monitoring programs to improve outcomes for patients receiving guideline-directed therapy.

Other studies and subgroups

In contrast to our study, two recent studies using observational data from the Swedish HF Registry observed a lower mortality rate and a higher rate of HF hospitalizations in the HFC compared to the PC group [13, 14]. However, their results may have been affected by residual confounding and imputed data. Secondly, the Swedish HF Registry uses a broad inclusion criterion, and it is not fully clear whether all patients were included following fully optimized medical treatment in an HFC, both factors limiting the comparison to our study. According to our knowledge, no previous trials have evaluated 10 years of follow-up in two different parts of a public health care system in a randomized clinical trial setting. We did not observe any additional effect of follow-up in a specialized HF clinic. This may be explained by several factors. First, there is a possibility of selection bias at enrolment. Patients included in a randomized clinical trial are generally healthier than patients in general [15], and it cannot be ruled out that a sicker population would have benefitted from continued follow-up. Second, the intervention was too weak considering that the patients were already receiving optimal medical therapy before randomization leaving only little room for further optimization. Third, cross over between the two arms. Within the original study period, only minor cross-over occurred [2] but during a 10 years period with a high proportion of HF re-hospitalizations, it may have occurred over time. Finally, no statistical interactions between treatment allocation and traditional subgroups on the risk of the primary outcome were observed, supporting the overall neutral result. Therefore, more sophisticated risk stratification than the identification of subgroups is probably needed in the future to identify patients that need specialized care for years [16].

Adherence to guideline therapy

In patients who were alive after 5 years, we evaluated the 5-year adherence to HF therapy. Here we did not observe any difference between groups. Considering that specialized HF clinics are designed to improve adherence, this finding was surprising. However, it supports the overall neutral result considering the lack of effect of patient education per se observed in the COACH trial [17]. It may be further explained by the fact that the patients were already on optimal medical therapy and all patients were educated in self-care and disease management. It should be noted that adherence to MRAs was poor in both groups. MRAs improve life expectancy considerably [18, 19] and more focus on adherence to MRA is needed in future studies together with the implementation of sacubitril-valsartan [20] and sodium-glucose inhibitors [21, 22]. Somewhat surprisingly, the proportion of patients with a PDC level>80% appeared to be slightly higher BB compared to RASi. However, it should be mentioned that the patients in the present study were made sure to tolerate the HF medication to the max tolerable dose before randomization, which may have ensured relatively high adherence to BB. Additionally, medications that are prescribed more than once daily complicate the calculation of PDC. Thus, calculations of PDC and differences in adherence between drugs should be interpreted with caution.

Clinical perspectives

We observed that although the patients were on optimal medical treatment, the mortality risk and HF hospitalization remained high for both patients followed in the PC and specialized HF clinics. Therefore, it may be suggested that improvement in monitoring HFrEF patients on already optimal medical therapy is needed. Follow-up by highly educated doctors and nurses who only treat HF patients compared to follow-up by nurses and doctors in primary care who treat several diseases daily did not result in an improvement in HF outcomes. Whether e.g the use of a CardioMems system can improve outcomes in less symptomatic patients is under investigation [23, 24]. Within the last years, new drugs have been developed–Sacubitril-Valsartan [20] and Sodium-dependent glucose cotransporters [21]–and implementation of these is also needed to improve clinical outcomes for HFrEF patients. Patients followed in the PC should be referred to specialized HF clinics to initiate these treatments and during a re-admission for worsening HF cardiologists should be ready to initiate new treatments to avoid delay in the initiation of new drug discoveries when endorsed into clinical guidelines [2528].

Methodological considerations

The strengths of this multicenter, open-labeled sub-study of 921 patients include a long and nearly complete follow-up period and a large number of events ensured by the comprehensive Danish registries. However, important limitations need to be addressed. First, patients were selected using a list of criteria, including HFrEF patients as well as excluding patients with NYHA-class 4, malignant disease, and an expected lifetime of < 5 years. Although the excluded group of patients may have had a larger number of events, this does not contradict our conclusion. However, the generalizability is limited to NYHA-class 1–3 HFrEF patients without recent malignant disease in a universal healthcare system such as Denmark. Additionally, the majority of the Danish population is Caucasian, thus our results may not be generalizable to non-Caucasian individuals. Secondly, cross-over after the follow-up end of the Northstar trial is a possibility, particularly given the numerous HF hospitalizations across the total follow-up period. However, for patients followed in the PC, we observed no gap in adherence to evidence-based medical treatment nor in survival during the first 5 years after follow-up. Furthermore, the results of this study depend on the quality of data including the discharge diagnosis. In this regard, it is important to note that the discharge diagnosis of HF has a low sensitivity [10], which could have underestimated the risk of HF hospitalization in both groups. Lastly, although type 2 errors cannot be excluded, we consider it unlikely given the robustness of our results in both primary and secondary outcomes.

Conclusions

HFrEF patients on optimal medical therapy did not benefit from extended follow-up in a specialized HF clinic. The risk of HF hospitalization and cardiovascular death, and adherence to the neurohormonal blockade, did not differ between patients followed in an HFC compared to PC. Given the high HF hospitalization and mortality rates, our results underscore the need for the development of improved monitoring programs including new technologies to improve outcomes for patients on guideline-directed therapy.

Clinical perspectives

Competency in medical knowledge

We observed that although the patients were on optimal medical treatment, the mortality risk and HF hospitalization remained high for both patients followed in the PC and specialized HF clinics. Therefore, it may be suggested that improvement in monitoring HFrEF patients on already optimal medical therapy is needed. Follow-up by highly educated doctors and nurses who only treat HF patients compared to follow-up by nurses and doctors in primary care who treat several diseases daily did not result in an improvement in HF outcomes.

Translational outlook

Whether e.g the use of a CardioMems system can improve outcomes in less symptomatic patients is under investigation [23, 24]. Within the last years, new drugs have been developed–Sacubitril-Valsartan [20] and Sodium-dependent glucose cotransporters [21]–and implementation of these is also needed to improve clinical outcomes for HFrEF patients.

Supporting information

S1 Methods. Inclusion and exclusion criteria.

(PDF)

S1 Table. Three most common primary causes of rehospitalizations (overnight stays only) during follow-up according to the type of disease.

(PDF)

S2 Table. The 8-year hazard rate of all-cause death, cardiovascular death, cardiovascular death or heart failure, and heart failure among 2-year survivors in groups defined by the number of prior hospitalizations for heart failure within the first two years following randomization.

(PDF)

S1 Fig. Flowchart.

(PDF)

S2 Fig. The 8-year absolute risk of all-cause death, cardiovascular death, discharge for heart failure, and cardiovascular death or discharge for heart failure in 2-year survivors in groups defined by the number of prior discharge diagnoses for heart failure.

(PDF)

Acknowledgments

The technical assistance from the staff at the Department of Clinical Chemistry, Frederiksberg University Hospital is deeply acknowledged. M. Malmborg and M. Schou had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

List of abbreviations

ARA

Aldosterone receptor antagonist

HF

Heart failure

HFrEF

Heart failure with reduced left ventricular ejection fraction

NT-proBNP

N-terminal pro-B-type Natriuretic Peptide

HFC

Heart failure clinic

PC

Primary care

RASi

Renin-angiotensin-system inhibitors

BB

beta-blockers

MRA

mineralocorticoid receptor antagonists

CV

Cardiovascular

PDC

proportion of days covered

Data Availability

Due to restrictions related to Danish law and protecting patient privacy, the combined set of data utilized in this present study can only be made available through a trusted third party, Statistics Denmark. Requests for data may be sent to Statistics Denmark at: http://www.dst.dk/en/OmDS/organisation/TelefonbogOrg.aspx?kontor=13&tlfbogsort=sektion or the Danish Data Protection Agency: https://www.datatilsynet.dk/english/contact-us.

Funding Statement

This work was funded by the Danish Heart Foundation (Grant number: 18-R121-A8218). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

References

  • 1.McDonagh TA, Metra M, Adamo M, Gardner RS, Baumbach A, Böhm M, et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J. 2021;42: 3599–3726. doi: 10.1093/eurheartj/ehab368 [DOI] [PubMed] [Google Scholar]
  • 2.Schou M, Gustafsson F, Videbaek L, Tuxen C, Keller N, Handberg J, et al. Extended heart failure clinic follow-up in low-risk patients: a randomized clinical trial (NorthStar). Eur Heart J. 2013;34: 432–442. doi: 10.1093/eurheartj/ehs235 [DOI] [PubMed] [Google Scholar]
  • 3.Lowrie R, Mair FS, Greenlaw N, Forsyth P, Jhund PS, McConnachie A, et al. Pharmacist intervention in primary care to improve outcomes in patients with left ventricular systolic dysfunction. Eur Heart J. 2012;33: 314–324. doi: 10.1093/eurheartj/ehr433 [DOI] [PubMed] [Google Scholar]
  • 4.Luttik MLA, Jaarsma T, van Geel PP, Brons M, Hillege HL, Hoes AW, et al. Long-term follow-up in optimally treated and stable heart failure patients: primary care vs. heart failure clinic. Results of the COACH-2 study. Eur J Heart Fail. 2014;16: 1241–1248. doi: 10.1002/ejhf.173 [DOI] [PubMed] [Google Scholar]
  • 5.Schou M, Gustafsson F, Videbaek L, Markenvard J, Ulriksen H, Ryde H, et al. Design and methodology of the NorthStar Study: NT-proBNP stratified follow-up in outpatient heart failure clinics—a randomized Danish multicenter study. Am Heart J. 2008;156: 649–655. doi: 10.1016/j.ahj.2008.06.007 [DOI] [PubMed] [Google Scholar]
  • 6.Pedersen CB. The Danish Civil Registration System. Scand J Public Health. 2011;39: 22–25. doi: 10.1177/1403494810387965 [DOI] [PubMed] [Google Scholar]
  • 7.Lynge E, Sandegaard JL, Rebolj M. The Danish National Patient Register. Scand J Public Health. 2011;39: 30–33. doi: 10.1177/1403494811401482 [DOI] [PubMed] [Google Scholar]
  • 8.Helweg-Larsen K. The Danish Register of Causes of Death. Scand J Public Health. 2011;39: 26–29. doi: 10.1177/1403494811399958 [DOI] [PubMed] [Google Scholar]
  • 9.Swedberg K, Cleland J, Dargie H, Drexler H, Follath F, Komajda M, et al. Guidelines for the diagnosis and treatment of chronic heart failure: executive summary (update 2005): The Task Force for the Diagnosis and Treatment of Chronic Heart Failure of the European Society of Cardiology. Eur Heart J. 2005;26: 1115–1140. doi: 10.1093/eurheartj/ehi204 [DOI] [PubMed] [Google Scholar]
  • 10.Kümler T, Gislason GH, Kirk V, Bay M, Nielsen OW, Køber L, et al. Accuracy of a heart failure diagnosis in administrative registers. Eur J Heart Fail. 2008;10: 658–660. doi: 10.1016/j.ejheart.2008.05.006 [DOI] [PubMed] [Google Scholar]
  • 11.Gerds TA. tagteam/heaven. 2023. Available: https://github.com/tagteam/heaven/blob/2ada3aa02b861f13b7e4a538c3e786304723201c/worg/medicin-macro.pdf [Google Scholar]
  • 12.R: The R Project for Statistical Computing. [cited 26 May 2023]. Available: https://www.r-project.org/
  • 13.Kapelios CJ, Canepa M, Benson L, Hage C, Thorvaldsen T, Dahlström U, et al. Non-cardiology vs. cardiology care of patients with heart failure and reduced ejection fraction is associated with lower use of guideline-based care and higher mortality: Observations from The Swedish Heart Failure Registry. Int J Cardiol. 2021;343: 63–72. doi: 10.1016/j.ijcard.2021.09.013 [DOI] [PubMed] [Google Scholar]
  • 14.Lindberg F, Lund LH, Benson L, Schrage B, Edner M, Dahlström U, et al. Patient profile and outcomes associated with follow-up in specialty vs. primary care in heart failure. ESC Heart Fail. 2022;9: 822–833. doi: 10.1002/ehf2.13848 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Rothwell PM. External validity of randomised controlled trials: “to whom do the results of this trial apply?” Lancet. 2005;365: 82–93. doi: 10.1016/S0140-6736(04)17670-8 [DOI] [PubMed] [Google Scholar]
  • 16.Rich JD, Burns J, Freed BH, Maurer MS, Burkhoff D, Shah SJ. Meta-Analysis Global Group in Chronic (MAGGIC) Heart Failure Risk Score: Validation of a Simple Tool for the Prediction of Morbidity and Mortality in Heart Failure With Preserved Ejection Fraction. J Am Heart Assoc. 2018;7: e009594. doi: 10.1161/JAHA.118.009594 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Jaarsma T, van der Wal MHL, Lesman-Leegte I, Luttik M-L, Hogenhuis J, Veeger NJ, et al. Effect of moderate or intensive disease management program on outcome in patients with heart failure: Coordinating Study Evaluating Outcomes of Advising and Counseling in Heart Failure (COACH). Arch Intern Med. 2008;168: 316–324. doi: 10.1001/archinternmed.2007.83 [DOI] [PubMed] [Google Scholar]
  • 18.Vaduganathan M, Claggett BL, Jhund PS, Cunningham JW, Pedro Ferreira J, Zannad F, et al. Estimating lifetime benefits of comprehensive disease-modifying pharmacological therapies in patients with heart failure with reduced ejection fraction: a comparative analysis of three randomised controlled trials. Lancet. 2020;396: 121–128. doi: 10.1016/S0140-6736(20)30748-0 [DOI] [PubMed] [Google Scholar]
  • 19.Ferreira JP, Docherty KF, Stienen S, Jhund PS, Claggett BL, Solomon SD, et al. Estimating the Lifetime Benefits of Treatments for Heart Failure. JACC Heart Fail. 2020;8: 984–995. doi: 10.1016/j.jchf.2020.08.004 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20.McMurray JJV, Packer M, Desai AS, Gong J, Lefkowitz MP, Rizkala AR, et al. Angiotensin-neprilysin inhibition versus enalapril in heart failure. N Engl J Med. 2014;371: 993–1004. doi: 10.1056/NEJMoa1409077 [DOI] [PubMed] [Google Scholar]
  • 21.McMurray JJV, Solomon SD, Inzucchi SE, Køber L, Kosiborod MN, Martinez FA, et al. Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction. N Engl J Med. 2019;381: 1995–2008. doi: 10.1056/NEJMoa1911303 [DOI] [PubMed] [Google Scholar]
  • 22.Packer M, Anker SD, Butler J, Filippatos G, Pocock SJ, Carson P, et al. Cardiovascular and Renal Outcomes with Empagliflozin in Heart Failure. N Engl J Med. 2020;383: 1413–1424. doi: 10.1056/NEJMoa2022190 [DOI] [PubMed] [Google Scholar]
  • 23.Abraham WT, Stevenson LW, Bourge RC, Lindenfeld JA, Bauman JG, Adamson PB, et al. Sustained efficacy of pulmonary artery pressure to guide adjustment of chronic heart failure therapy: complete follow-up results from the CHAMPION randomised trial. Lancet. 2016;387: 453–461. doi: 10.1016/S0140-6736(15)00723-0 [DOI] [PubMed] [Google Scholar]
  • 24.Lindenfeld J, Zile MR, Desai AS, Bhatt K, Ducharme A, Horstmanshof D, et al. Haemodynamic-guided management of heart failure (GUIDE-HF): a randomised controlled trial. Lancet. 2021;398: 991–1001. doi: 10.1016/S0140-6736(21)01754-2 [DOI] [PubMed] [Google Scholar]
  • 25.Fang JC. Heart-Failure Therapy—New Drugs but Old Habits? N Engl J Med. 2019;381: 2063–2064. doi: 10.1056/NEJMe1912180 [DOI] [PubMed] [Google Scholar]
  • 26.Bhatt DL, Szarek M, Steg PG, Cannon CP, Leiter LA, McGuire DK, et al. Sotagliflozin in Patients with Diabetes and Recent Worsening Heart Failure. N Engl J Med. 2021;384: 117–128. doi: 10.1056/NEJMoa2030183 [DOI] [PubMed] [Google Scholar]
  • 27.Velazquez EJ, Morrow DA, DeVore AD, Duffy CI, Ambrosy AP, McCague K, et al. Angiotensin-Neprilysin Inhibition in Acute Decompensated Heart Failure. N Engl J Med. 2019;380: 539–548. doi: 10.1056/NEJMoa1812851 [DOI] [PubMed] [Google Scholar]
  • 28.Ponikowski P, Kirwan B-A, Anker SD, McDonagh T, Dorobantu M, Drozdz J, et al. Ferric carboxymaltose for iron deficiency at discharge after acute heart failure: a multicentre, double-blind, randomised, controlled trial. Lancet. 2020;396: 1895–1904. doi: 10.1016/S0140-6736(20)32339-4 [DOI] [PubMed] [Google Scholar]

Decision Letter 0

Giuseppe Gargiulo

22 Nov 2022

PONE-D-22-18899Specialized heart failure clinics versus primary care: Extended registry-based follow-up of the NorthStar TrialPLOS ONE

Dear Dr. Malmborg,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jan 06 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Giuseppe Gargiulo, MD, PhD

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at 

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and 

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match. 

When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section.

3. Thank you for stating the following financial disclosure: 

"This work was funded by the Danish Heart Foundation (Grant number: 18-R121-A8218). "

  

Please state what role the funders took in the study.  If the funders had no role, please state: "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript." 

If this statement is not correct you must amend it as needed. 

Please include this amended Role of Funder statement in your cover letter; we will change the online submission form on your behalf.

4. We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For more information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. 

In your revised cover letter, please address the following prompts:

a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially sensitive information, data are owned by a third-party organization, etc.) and who has imposed them (e.g., an ethics committee). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent.

b) If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings as either Supporting Information files or to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories.

We will update your Data Availability statement on your behalf to reflect the information you provide.

Additional Editor Comments:

This is an interesting study.

It would be interesting to account for additional events during follow-up. Please include an additional analysis comparing groups based on number of HF re-hospitalizations.

Please check figure 1, the titles on the KM curves seem not corresponding to the figure caption.

Please better comment on the borderline P for interaction for AF in Fig 2. Statistical significance could be missing simply due to power issues.

Can the authors provide more information on the reasons for re-hospitalizations during the follow-up?

The rates of device therapy at randomization is very low. It would be important to have info during follow-up.

Please add more details on the initial trial. The paper must be self-standing and the readers/reviewers should not go searching for other info from different prior publications.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: PONE-D-22-18899: statistical review

This study compares long-term survival between heart failure patients who have been randomly assigned to follow-up in a specialized HF clinic or primary care. 5-year adherence to prescribed neurohormonal blockade in 5-year survivors is also assessed. Traditional survival analysis methods are correctly exploited to compare the survival trajectories between the two groups and beta regression is correctly considered for comparing adherence proportions. I have nothing to say about this paper: the research question is well posed, statistical methods are appropriate, results are correctly interpreted and possible limitations of the study are nicely remarked in the discussion.

Reviewer #2: In this manuscript, authors report findings from the extended follow-up of a trial conducted in Denmark (NorthStar) that randomized patients with heart failure with reduced ejection fraction (HFrEF) to be followed up in primary care or in a specialized HF clinic once treatment had been optimized.

FU data were obtained using linked electronic health records.

Overall, the manuscript is clear and easy to read till the end.

However, I think that the main limitation of this study, as acknowledged by the authors, is that during a period of up to 10 years many bad things can happen to patients with heart failure, and a substantial proportion of those randomized to a primary care clinic follow-up would have received specialist input due to clinical deterioration which, in my opinion, limits the relevance of these findings.

Authors might add a comment to adherence to beta-blockers, which seems higher that that to RASi.

Reviewer #3: The authors present a very interesting study on the value of specialized heart failure clinics versus primary care. It is a relevant study, but I have some comments:

- Although an NT-proBNP > 1000 pg/mL might identify high-risk patients, an HF hospitalization (43% in the initial study) the previous year might be a marker of higher risk than NTproBNP values.

- The authors use both MRA and ARA. ARA is not defined in the Abbreviation nor Table 1. Interestingly, the use of MRA appears to increase from randomization (33%) to the 5-year follow-up MRA (HFC: 51.9%; PC: 52.0%). It may be associated with the publication of pivotal MRA trials in HF. However, it is surprising that PC prescribed MRA at a relatively high percentage.

- Was CRT or ICD different at 5-year follow-up? The use at baseline is surprisingly low.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (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. Registration is free. 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 PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Decision Letter 1

Giuseppe Gargiulo

6 Mar 2023

PONE-D-22-18899R1Specialized heart failure clinics versus primary care: Extended registry-based follow-up of the NorthStar TrialPLOS ONE

Dear Dr. Malmborg,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Apr 20 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Giuseppe Gargiulo, MD, PhD

Academic Editor

PLOS ONE

Additional Editor Comments:

The authors provided a properly revised version of the manuscript with almost all points addressed.

There is still 1 of my previous points to be addressed, specifically point 1.4 in which I did not ask for specific new analyses but simply a table or text reporting reasons of re-hospitalizations during follow-up (new acute coronary syndrome, infections, diuretic resistance, worsening of renal function etc.).

Also few points from reviewer 4 should be addressed.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: No

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: Authors performed additional analyses but I still think that the main limitation of this study remains a (very likely) high rate of cross over: as acknowledged, a substantial proportion of those randomized to a primary care clinic follow-up had been admitted with heart failure and would have received specialist input due to clinical deterioration. This, in my opinion, limits

the relevance of these findings that could be, eventually, summarised in a much shorter research letter.

Reviewer #3: All comments have been addressed by the authors. I believe the manuscript can be published in the current form.

Reviewer #4: In this manuscript, Dr. Malmborg and colleagues tried to assess if there is a difference in hospitalization for heart failure or cardiovascular mortality comparing specialized heart failure clinics versus primary care through an extended post-hoc registry-based follow-up study of a randomized controlled trial.

Overall, this is a quite nicely written article, greatly improved already by previous revisions, with a clinical relevance.

However, some relevant issues need to be addressed by the authors:

- Albeit the study was conducted rigorously, the result is in contrast to recent results from registry studies involving far larger numbers of patients (https://onlinelibrary.wiley.com/doi/full/10.1002/ehf2.13848; https://www.internationaljournalofcardiology.com/article/S0167-5273(21)01334-6/fulltext). This should be expanded upon in the discussion section, pointing out why there may be this discrepancy.

- Table 1: The authors report an haemoglobin mean level of 8.6, but only about 20% of patients with anemia. How is this possible? What are the upper letter a in anemia and upper letter b in hyponatremia for?

- Figure 2: On the bottom near the hazard ratio should be specified whether left or right is in favour of HFC or PC

- Please note that the text requires a careful proofreading, since there are several grammar lapses

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

Reviewer #3: No

Reviewer #4: Yes: Christian Basile

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (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. Registration is free. 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 PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PLoS One. 2023 Jun 8;18(6):e0286307. doi: 10.1371/journal.pone.0286307.r004

Author response to Decision Letter 1


27 Apr 2023

Dear Giuseppe Gargiulo and reviewers

The current study has previously been under review twice by Plos One and was ultimately encouraged to be resubmitted with positive reviews and minor comments. We thank you for your previous constructive criticism of our manuscript. The manuscript has undergone a revision according to the suggestions by the reviewers, and we think the manuscript has been improved, and we kindly ask you to consider the manuscript for publication in Plos One. We have addressed the comments by the editor and reviewers, and we hope that with these changes, the manuscript will be acceptable for consideration in Plos One.

On behalf of the authors,

Yours sincerely,

Morten Malmborg, MD

Corresponding author

Attachment

Submitted filename: Response ot reviewers2.docx

Decision Letter 2

Giuseppe Gargiulo

15 May 2023

Specialized heart failure clinics versus primary care: Extended registry-based follow-up of the NorthStar Trial

PONE-D-22-18899R2

Dear Dr. Malmborg,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Giuseppe Gargiulo, MD, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

All comments were addressed. The manuscript is improved and can now be accepted for publication.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #4: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #4: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #4: The manuscript was greatly improved, the images are now clearer and as it is I have no further comment.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #4: Yes: Basile Christian

**********

Acceptance letter

Giuseppe Gargiulo

31 May 2023

PONE-D-22-18899R2

Specialized heart failure clinics versus primary care: Extended registry-based follow-up of the NorthStar Trial

Dear Dr. Malmborg:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Giuseppe Gargiulo

Academic Editor

PLOS ONE

Associated Data

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

    Supplementary Materials

    S1 Methods. Inclusion and exclusion criteria.

    (PDF)

    S1 Table. Three most common primary causes of rehospitalizations (overnight stays only) during follow-up according to the type of disease.

    (PDF)

    S2 Table. The 8-year hazard rate of all-cause death, cardiovascular death, cardiovascular death or heart failure, and heart failure among 2-year survivors in groups defined by the number of prior hospitalizations for heart failure within the first two years following randomization.

    (PDF)

    S1 Fig. Flowchart.

    (PDF)

    S2 Fig. The 8-year absolute risk of all-cause death, cardiovascular death, discharge for heart failure, and cardiovascular death or discharge for heart failure in 2-year survivors in groups defined by the number of prior discharge diagnoses for heart failure.

    (PDF)

    Attachment

    Submitted filename: Response ot reviewers.docx

    Attachment

    Submitted filename: Response ot reviewers2.docx

    Data Availability Statement

    Due to restrictions related to Danish law and protecting patient privacy, the combined set of data utilized in this present study can only be made available through a trusted third party, Statistics Denmark. Requests for data may be sent to Statistics Denmark at: http://www.dst.dk/en/OmDS/organisation/TelefonbogOrg.aspx?kontor=13&tlfbogsort=sektion or the Danish Data Protection Agency: https://www.datatilsynet.dk/english/contact-us.


    Articles from PLOS ONE are provided here courtesy of PLOS

    RESOURCES