The prevalence and management of angina among patients with chronic coronary artery disease across US outpatient cardiology practices: insights from the Angina Prevalence and Provider Evaluation of Angina Relief (APPEAR) study

Abstract

Although eliminating angina is a primary goal in treating patients with chronic coronary artery disease (CAD), few contemporary data quantify prevalence and severity of angina across US cardiology practices. The authors hypothesized that angina among outpatients with CAD managed by US cardiologists is low and its prevalence varies by site. Among 25 US outpatient cardiology clinics enrolled in the American College of Cardiology Practice Innovation and Clinical Excellence (PINNACLE) registry, we prospectively recruited a consecutive sample of patients with chronic CAD over a 1‐ to 2‐week period at each site between April 2013 and July 2015, irrespective of the reason for their appointment. Eligible patients had documented history of CAD (prior acute coronary syndrome, prior coronary revascularization procedure, or diagnosis of stable angina) and ≥1 prior office visit at the practice site. Angina was assessed directly from patients using the Seattle Angina Questionnaire Angina Frequency score. Among 1257 patients from 25 sites, 7.6% (n = 96) reported daily/weekly, 25.1% (n = 315) monthly, and 67.3% (n = 846) no angina. The proportion of patients with daily/weekly angina at each site ranged from 2.0% to 24.0%, but just over half (56.3%) were on ≥2 antianginal medications, with wide variability across sites (0%–100%). One‐third of outpatients with chronic CAD managed by cardiologists report having angina in the prior month, and 7.6% have frequent symptoms. Among those with frequent angina, just over half were on ≥2 antianginal medications, with wide variability across sites. These findings suggest an opportunity to improve symptom control.

1. INTRODUCTION

Unlike patients with acute coronary syndromes (ACS), patients with chronic coronary artery disease (CAD) are predominantly managed in the outpatient setting, with therapies directed toward preventing cardiovascular events, improving survival, and controlling angina symptoms.1, 2, 3 Although the prevalence and treatment patterns for ACS are well known,4, 5, 6 data about the prevalence and management of angina among outpatients with chronic CAD are sparse.7, 8, 9, 10, 11, 12, 13 The American College of Cardiology outpatient Practice Innovation and Clinical Excellence (PINNACLE) registry (a national practice‐based cardiovascular quality‐improvement program sponsored by the National Cardiovascular Data Registry)14 has provided an important opportunity to better understand current treatment patterns and the opportunity to improve the outpatient management of cardiovascular diseases, particularly with respect to secondary prevention.15, 16 Although PINNACLE includes the potential to capture patient‐reported health status (angina symptoms, functional limitations, and quality of life) using the Seattle Angina Questionnaire (SAQ), this is rarely done.17, 18 Accordingly, no patient‐reported assessments of angina are currently collected in PINNACLE, which is a substantial gap in knowledge, given that symptom control is a primary goal of stable ischemic heart disease management.19

To address this gap in knowledge, we prospectively surveyed patients presenting to US cardiology practices participating in PINNACLE to better understand the prevalence and management of angina among US outpatients with CAD. Examining the prevalence of angina among outpatients with CAD and the intensity of its management by cardiovascular specialists is the first step toward evaluating the potential of symptom control to serve as a measure of healthcare quality.

2. METHODS

The Angina Prevalence and Provider Evaluation of Angina Relief (APPEAR) study was a cross‐sectional, multicenter survey investigating the burden and management of angina among patients with chronic CAD in outpatient cardiology clinics across the United States. Sites were recruited from those participating in the PINNACLE registry between April 2013 and July 2015. A total of 25 US sites were enrolled in the study and prospectively recruited 25 to 70 consecutive patients with chronic CAD over a 1‐ to 2‐week period, irrespective of the reason for their appointment (ie, no effort was made to recruit patients presenting for angina management, per se). Eligible patients were those age >18 years with a documented history of CAD (documented prior ACS, prior coronary revascularization procedure, or diagnosis of stable angina), ≥1 prior office visit at the practice site, and prior receipt of prn nitrate therapy for symptomatic angina relief. Patients were excluded if they were unable or unwilling to fill out the patient questionnaire. Comprehensive data regarding baseline patient demographics, comorbidities, medications, health status, and provider management decisions were obtained through patient, nurse, and provider case‐report forms filled out during each office visit. Each participating site obtained institutional research board approval, and all patients provided written informed consent for study enrollment and data collection. All investigations were in accordance with the Declaration of Helsinki.

Patient‐reported angina was assessed using the SAQ, a disease‐specific instrument consisting of 19 items that measures 5 clinically relevant domains of health status in patients with CAD.18 It has been shown to be valid, reproducible, and responsive to changes in health status of patients with CAD. The SAQ Angina Frequency (SAQ AF) domain, the primary outcome of this study, quantifies the frequency of angina over the prior 4 weeks and has been shown to correlate well with patient‐reported daily diaries of angina.20 Congruent with prior work, SAQ AF scores were categorized as daily/weekly angina (scores ≤60), monthly angina (scores 61–99), and no angina (score = 100).18, 20 Patients reporting daily or weekly angina were considered to have frequent angina.

Antianginal pharmacologic therapy for this study included β‐blockers, calcium channel blockers, long‐acting nitrates (oral and dermal therapies), and ranolazine. Congruent with the Appropriate Use Criteria,21 optimal antianginal therapy was defined as being on ≥2 of the above medications. Medication adherence was assessed by responses to questions from the Medications Discussion Questionnaire (MedDQ).22

Univariate statistics were used to describe the characteristics of the study population, with mean (SD) for continuous variables, and counts and percentages for categorical variables overall and by categories of angina frequency: daily/weekly (SAQ AF ≤60), monthly (SAQ AF = 61–99), and none (SAQ AF = 100). To examine the variability across sites, we assessed the proportion of patients with daily/weekly (frequent) angina at each site. Last, to evaluate the intensity of antianginal therapy among patients with frequent angina, we looked at the proportion treated with optimal medical antianginal therapy (≥2 antianginal medications) by site. This was done to describe the intensity of antiangina management in highly symptomatic patients, a potential opportunity to improve symptom control. All analyses were conducted with SAS version 9.4 (SAS Institute Inc., Cary, North Carolina) and R version 2.15.3 (R Foundation for Statistical Computing, http://www.r‐project.org).

3. RESULTS

Among 1259 outpatients with CAD seen by 155 cardiologists across 25 US sites, 1257 (99.8%) had available SAQ AF domain scores and a complete medication list and were included in our analytic cohort. Mean age (SD) of the patient cohort was 71.1 ± 11.1 years, 68.4% were men, 89.7% were white, and the majority reported compliance with medications (Table 1). The diagnosis of CAD was made by a diagnosis of prior myocardial infarction in 38.4%, prior percutaneous coronary intervention in 62.4%, and prior coronary artery bypass grafting surgery in 37.4%. Dyslipidemia (84.4%) and hypertension (79.8%) were common, and 35.4% had diabetes mellitus. The majority of patients were taking aspirin (87%) and a statin (86.2%).

Table 1.

Analytic cohort patient characteristics

	Total, N = 1257
Age, y, mean (SD)	71.1 (11.1)
Male sex, n (%)	860 (68.4)
Race, n (%)
White	1128 (89.7)
Black	53 (4.2)
Other	76 (6.0)
Married, n (%)	822 (66.1)
Insurance, n (%)
Private	607 (48.6)
Medicare (fee‐for‐service)	601 (48.1)
Medicare (managed care)	257 (20.6)
Medicaid	48 (3.8)
None	8 (0.6)
Insurance coverage for medications, n (%)	1197 (96.1)
How often did you forget your medications? n (%)
Never	673 (53.8)
Once in the past month	278 (22.2)
2 to 3 times in the past month	212 (17.0)
Once per week	51 (4.1)
Several times per week	21 (1.7)
Every day or nearly every day	15 (1.2)
How often did you skip your medications? n (%)
Never	1074 (85.5)
Once in the past month	73 (5.8)
2 to 3 times in the past month	56 (4.5)
Once per week	19 (1.5)
Several times per week	20 (1.6)
Every day or nearly every day	14 (1.1)
Smoking status, n (%)
Never smoked	363 (29.3)
Prior smoker	135 (10.9)
Stopped >1 year ago	577 (46.6)
Stopped within past 12 months	38 (3.1)
Smoked within past 30 days	125 (10.1)
Medications, n (%)
ASA	1094 (87.0)
Statin	1083 (86.2)
P2Y12 inhibitor	431 (34.3)
Medical history, n (%)
PVD	313 (24.9)
AF	290 (23.1)
HF	231 (18.4)
Dyslipidemia	1060 (84.4)
DM	444 (35.4)
HTN	1002 (79.8)
Stroke/TIA	96 (7.6)
CKD	157 (12.5)
Lung disease	127 (10.1)
Patient‐reported angina based on SAQ‐AF, n (%)
None	846 (67.3)
Monthly	315 (25.1)
Daily/weekly	96 (7.6)
SAQ domain scores, mean (SD)
QoL	79.3 (20.3)
Angina frequency	91.6 (15.8)
Physical limitation	71.6 (25.4)

Abbreviations: AF, atrial fibrillation; ASA, aspirin; CKD, chronic kidney disease; DM, diabetes mellitus; HF, heart failure; HTN, hypertension; PVD, peripheral vascular disease; QoL, quality of life; SAQ AF, Seattle Angina Questionnaire Angina Frequency; SD, standard deviation; TIA, transient ischemic attack.

Of the 1257 patients with CAD, 411 patients (32.7%) reported ≥1 episode of angina over the 4 weeks prior to their visit, with the remaining reporting being angina‐free (Figure 1). Among those reporting angina, 23.3% (n = 96) reported symptoms occurring on a daily/weekly basis, whereas the remainder (76.7%) had monthly angina. Among patients with daily/weekly angina, 56.3% were on optimal antianginal therapy (≥2 antianginal medications; Figure 2).

Figure 1.

Frequency of patient reported angina as measured by the SAQ AF domain score among stable CAD patients (n = 1257). Abbreviations: CAD, coronary artery disease; SAQ AF, Seattle Angina Questionnaire Angina Frequency.

Figure 2.

Intensity of antianginal pharmacologic management for patients with frequent (daily/weekly) angina (n = 96).

There was substantial variability in the prevalence of frequent (daily/weekly) angina and in the intensity of antianginal therapy across practice sites (Figure 3). The proportion of patients with frequent angina at each site ranged from 2.0% to 24.0%. Among these, the proportion of patients at each practice on optimal antianginal therapy ranged from 0 to 100%. Only 6 of the 25 sites treated all of their daily/weekly angina patients with ≥2 antianginal medications.

Figure 3.

Proportion of patients with CAD and frequent (daily/weekly) angina (n = 96) and the proportion of frequent angina patients treated with optimal medical antianginal therapy (≥2 medications) by site. Abbreviations: CAD, coronary artery disease.

4. DISCUSSION

This is the first study, of which we are aware, to document the frequency of angina in US cardiology practices. Among a cohort of 1257 outpatients with CAD managed by 155 cardiologists across 25 US sites, we found that a third of patients reported angina in the month prior to their clinic visit, with 8% having frequent symptoms that occurred every day or every week. Among those with frequent symptoms, only 56% were on optimal antianginal medications. Moreover, we noted wide variability in frequent angina and optimal antianginal medications across sites. These findings suggest an important opportunity to better identify and treat angina symptoms in outpatients with CAD.

Although therapeutic options for the management of angina have evolved over time, literature on contemporary patterns of the burden and management of angina in outpatients with CAD is limited. We found only 2 contemporary multicenter studies, conducted outside of the United States, which evaluated the prevalence, frequency, and management of angina in stable CAD outpatients using a validated, disease‐specific health status measure. The first study, Coronary Artery Disease in General Practice (CADENCE), was a cross‐sectional study that enrolled 2031 consecutive patients with a diagnosis of stable angina among 207 primary‐care practitioners in Australia between the years 2006 and 2007.7 Frequent angina, assessed by the SAQ, was noted in 29% of patients, with wide variability across practices (range, 0–100%) Although the intensity of antianginal therapy was not explored, it was noted that only 54% of frequent angina patients were on either a β‐blocker or nitrate. The second study was a cross‐sectional, multicenter study in Spain that enrolled 2039 stable angina outpatients cared for by 419 cardiologists between the years 2009 and 2010.8 Angina was also assessed with the SAQ, and nearly half (49.7%) of patients reporting frequent angina symptoms. Our results differ from these studies in that we found a much lower prevalence of frequent angina, which may reflect differences in the recognition and management by provider type (eg, cardiologist vs general practitioner) or by country (eg, more frequent use of revascularization in the United States). Nonetheless, our results and those of these prior studies underscore the need for further work on defining and disseminating best‐practice patterns for identifying and managing CAD outpatients’ angina.

One potential means to improve treatment of angina would be to routinely and systematically quantify patients’ angina at each clinic visit. Several organizations have already made calls for using patient‐reported outcomes as a foundation for quality assessment and improvement in patients with CAD.23, 24, 25 Such efforts offer the potential to better evaluate and document control of angina, support quality‐improvement efforts, and enable the sharing of best practices, all of which may improve the symptoms and quality of life of patients with chronic CAD. In the current era of electronic medical records and the growing use of patient portals, integrating formal angina assessments with the SAQ seems feasible, but future work is needed to integrate such assessments into routine clinical care.

Our study should be interpreted in the context of the following potential limitations. First, although we were able to enroll a large number of patients seen by cardiologists across a geographically broad range of US practices, our patient population was predominantly white, male, and insured. Accordingly, the angina frequency and management of patients across a broader cohort of patients in the US may differ from our study. Second, participation in APPEAR was limited to cardiology practices already participating in PINNACLE, a national cardiovascular quality‐improvement registry. Accordingly, it is possible that our observed rates of angina and management intensity are better than that of patients being cared for by practices not enrolled in quality‐improvement registries or initiatives. Third, as there are no risk‐adjustment models available for angina control, we were unable to account for patient factors that may have contributed to the variability in frequent angina across sites. However, given the low threshold for defining optimal medical management of angina used in this study, it is unlikely that patient factors that would vary by site would preclude more aggressive efforts at symptom control.

5. CONCLUSION

In a contemporary, multicenter study of outpatient cardiology practices, we found that a third of outpatients with CAD reported angina in the month prior to the clinic visit. Among patients with frequent angina, 44% were on suboptimal antianginal pharmacologic therapy, with wide variability across sites. These findings suggest that continued efforts toward establishing a foundation and framework for quantifying, interpreting, and managing symptom control may be an important opportunity to improve care in chronic CAD.

Conflicts of interest

Faraz Kureshi and Ali Shafiq received support from the National Heart, Lung, and Blood Institute of the National Institutes of Health under award no. T32HL110837. Dr. Spertus received funding from Gilead Sciences to conduct this study, although the sponsor had no input on the design, analysis, interpretation, or decision to publish these results. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Kureshi F, Shafiq A, Arnold SV, Gosch K, Breeding T, Kumar AS, Jones PG and Spertus JA. The prevalence and management of angina among patients with chronic coronary artery disease across US outpatient cardiology practices: insights from the Angina Prevalence and Provider Evaluation of Angina Relief (APPEAR) study, Clin Cardiol, 2017;40(1):6–10.