Heart rate and the use of beta-blockers in stable outpatients with coronary artery disease: Polish baseline results of the CLARIFY registry

Background: Heart rate (HR) is an important risk factor in coronary artery disease (CAD). However, there is little contemporary data on HR and the use of HR-lowering medications, particularly beta-blockers, among patients with stable CAD in routine clinical practice. Aim: To describe HR in the Polish population of the CLARIFY registry, overall and in relation to beta-blocker use, and to assess the determinants of HR. Methods and results: CLARIFY is an international, prospective, observational, longitudinal registry of outpatients with stable CAD, defined as either prior myocardial infarction or revascularisation procedure, or evidence of coronary stenosis of at least 50%, or chest pain associated with proven myocardial ischaemia. A total of 33,438 patients from 45 countries in Europe, the Americas, Africa, the Middle East, and Asia/Pacific were enrolled between November 2009 and July 2010. In Poland, 1,004 patients were enrolled between February and June 2010, which was the largest population among countries from Eastern Europe. Most patients were men (72.8%). Mean +/- standard deviation age was 62.1 +/- 9.1 years. HR determined by pulse was 69.3 +/- 9.4 bpm and by electrocardiogram was 68.2 +/- 10.6 bpm. Beta-blockers were used in 89.9% of patients. Resting HR >= 70 bpm was noted in 49.3% of all patients and in 48.6% of patients on beta-blockers. Resting HR >= 70 bpm was significantly more frequent among younger patients, and in those with diabetes, those being treated for arterial hypertension, and who lacked regular physical activity. Patients with HR >= 70 bpm at rest had more frequent symptoms of angina and more frequently needed hospitalisation due to heart failure. Conclusions: Despite a very high rate of beta-blocker use, almost 50% of patients with stable CAD had a resting HR >= 70 bpm, which was associated with more frequent angina and ischaemia. Further HR lowering is possible in many patients with CAD. Whether or not this will improve symptoms and outcomes is under investigation.