The prognostic significance of post-infarction angina pectoris and the effect of verapamil on the incidence of angina pectoris and prognosis. The Danish Study Group on Verapamil in Myocardial Infarction.

The prognostic significance of angina pectoris and the effect of intervention with verapamil on the incidence of angina pectoris were studied in patients recovering from myocardial infarction and included in the Danish Verapamil Infarction Trial II. During the second week after admission patients were doubly-blindly randomized to treatment with verapamil 360 mg.day-1 or placebo. Treatment was continued for up to 18 months. At discharge angina pectoris was reported in 11% of 869 patients randomized to verapamil and in 12% of 888 randomized to placebo (ns). One month after discharge a significant increase in the prevalance of angina pectoris was reported in both the verapamil (33%) (P < 0.001) and the placebo groups (39%) (P < 0.001). The one month prevalence of angina pectoris (P = 0.03) and the 18 months overall incidence of angina pectoris (P = 0.002) were both significantly lower in the verapamil group compared with placebo. Stable angina pectoris during the first month of follow-up was a significant predictor of major events (i.e. death or reinfarction) (hazard ratio = 1.45; 95% confidence limits: 1.10, 1.89). As verapamil significantly reduced the incidence of angina pectoris during daily activities, and thereby the number of patients at high risk, the beneficial effect of verapamil in reducing major events in patients recovering from myocardial infarction is likely to be due to abolishing myocardial ischaemia.