Angina May Be More Prevalent among Stable CAD Patients than Physicians Suspect

A study on the prevalence of angina among outpatients with coronary artery disease (CAD) published recently in the Archives of Internal Medicine found that nearly one-third of patients with stable CAD experienced angina at least once a week.

According to a news release the authors of the study, titled “The Prevalence of Weekly Angina Among Patients With Chronic Stable Angina in Primary Care Practices,” measured angina frequency in the CAD in General Practice (CADENCE) Study, using the Seattle Angina Questionnaire (SAQ) in more than 2,000 patients in Australian primary care clinics. Among the patients studied who had stable CAD, 29% of patients reported having weekly angina, defined as “one or more episodes per week over the preceding four weeks.” This was associated with “greater physical limitations and worse quality of life (24% and 27% lower SAQ scores, respectively),” compared with patients who had “minimal angina” (defined in the study abstract as “angina less than once a week over the preceding 4 weeks”).

Female patients, patients with a history of heart failure, and patients with peripheral artery disease were more likely to experience more frequent angina. The study also found that physicians tended to underestimate the severity of the problem—primary care physicians “considered patients’ angina to be optimally controlled in 80% of cases overall, and in 48% and 37% of patients reporting weekly and daily angina, respectively.”

Another interesting finding from the study was the “marked variability” of angina control and prevalence across participating practices. Some practices had zero patients who reported weekly angina, whereas some had 100% of patients reporting that they experienced weekly angina—“Twenty-nine (14%) clinics had no patients with weekly angina, while at least half of patients reported weekly angina at 35 (18%) clinics, and all of the patients at eight (4%).”

The study authors said that clinicians should “take heed and closely assess angina frequency and its impact on their patients,” because the “prevalence, consequences, and variability (with presumed opportunity for improvement), argue strongly that reproducible estimates of angina could be a valuable outcome measure of quality for outpatients with CAD.”