Treatment of angina pectoris with calcium antagonists: long-term follow-up.

Abstract

This study was designed to investigate the association of calcium channel blocker (CCB) use with subsequent mortality in a group of patients with chronic stable angina. CCBs have been proven effective in the treatment of angina pectoris. Recently, the safety of CCBs in hypertensive and coronary artery disease patients has been challenged. New prospective controlled studies with nifedipine are under way that may help define the long-term safety of CCBs in the treatment of these patients. Until these studies are concluded, long-term data on mortality among CCB users may be informative. From 1990 to 1992, 11,575 patients with coronary heart disease were screened but not included in a secondary prevention study with bezafibrate conducted in 18 cardiac departments in Israel. Of these patients, 2390 had chronic angina without a history of myocardial infarction and were followed for subsequent mortality over 4-6 years (mean 5.2 years). From this patient population, 1366 (57%) reported receiving a CCB. They included more women and hypertensives, and a greater proportion of them exhibited a higher severity of anginal class than counterparts not treated with a CCB (n = 1024). The mortality in patients treated with CCBs was similar to those not treated with CCBs (11.5% vs. 11.6%; P = 0.53). A multivariate analysis accounting for differences in age, sex, and other clinical parameters associated with increased risk evaluated the estimated hazard ratio (HR) of death of patients treated with CCBs compared with those not treated with CCBs (HR = 0.89; 95% CI = 0.68-1.16). In Cox regression analysis, the adjusted HR of death of patients treated with nifedipine or diltiazem, together with a beta-blocker, was 0.85 (95% CI = 0.47-1.54) and 0.47 (95% CI = 0.24-0.90), respectively. After a follow-up of 4-6 years (mean 5.2) there was no evidence of increased mortality risk associated with CCB use among coronary heart disease patients with chronic stable angina. However, due to wide confidence intervals and possible confounding factors, randomized control studies are required to provide definitive information.