The prevalence of weekly angina among patients with chronic stable angina in primary care practices: The Coronary Artery Disease in General Practice (CADENCE) Study.

BACKGROUND Angina, the cardinal symptom of coronary artery disease (CAD), is amenable to a range of therapies, and its routine assessment is considered a performance measure of quality. However, the prevalence of frequent angina among outpatients with CAD is unknown. METHODS The Coronary Artery Disease in General Practice (CADENCE) Study utilized a cluster-stratified, cross-sectional design to examine angina frequency in patients with stable angina attending Australian primary care practices. The 207 participating primary care practitioners recruited 2031 consecutive patients, irrespective of the purpose of their visit. Angina frequency was quantified with the Seattle Angina Questionnaire (SAQ), and weekly angina was defined as having 1 or more episodes per week over the preceding 4 weeks [hereinafter, "weekly (> or =1) angina"]. RESULTS Among primary care practice patients with stable angina, 29% (95% confidence interval [CI], 26%-31%) experienced weekly (> or =1) angina, which was associated with greater physical limitations and worse quality of life (24% and 27% lower SAQ scores, respectively; P < .05) compared with those with minimal angina (angina less than once a week over the preceding 4 weeks). The proportion of patients with weekly (> or =1) angina within a clinic ranged from none (14% of clinics) to more than 50% (18% of clinics). Patient characteristics associated with weekly (> or =1) angina included female sex (odds ratio [OR], 1.42; 95% CI, 1.13-1.78), a history of heart failure (OR, 1.59; 95% CI, 1.22-2.08), and peripheral artery disease (OR 1.89; 95% CI, 1.42-2.51; P < .001 for all comparisons). CONCLUSIONS Almost 1 in 3 patients with stable angina attending primary care practices had angina at least once a week, which was associated with worse quality of life. Moreover, weekly (> or =1) angina varied considerably across clinics, possibly reflecting variability in the identification and management of angina. The potential role of an angina performance measure to improve patients' outcomes, including symptom control, warrants further consideration.