The prognostic significance of post-infarction angina pectoris and the effect of verapamil on the incidence of angina pectoris and prognosis

The prognostic sign of angina pectoris and the effect of interventionwith verapamil on the incidence of angina pectoris were studiedin patients recovering from myocardial infarction and includedin the Danish Verapamil Infarction Trial II. During the secondweek after admission patients were double-blindly randomizedto treatment with verapamil 360 mg. day^–1 or placebo.Treatment was continued for up to 18 months. At discharge anginapectoris was reported in 11% of 869 patients randomized to verapamiland in 12% of 888 randomized to placebo (ns). One month afterdischarge a significantly increase in the prevalance of anginapectoris was reported in both the verapamil (33%) (P<0·001)and the placebo groups (39%) (P <0·001). The one monthprevalence of angina pectoris (P=0·03) and the 18 monthsoverall incidence of angina pectoris (P= 0·002) wereboth .sigificant lower in the verapamil group compared withplacebo. Stable angina pectoris during the first month of follow-upwas a significant predictor of major events (i.e. death or reinfarction)(hazard ratio = 1·45; 95% confidence limits: 1·101·89). As verapamil significantly reduced the incidenceof angina pectoris during daily activities, and thereby thenumber of patients at high risk, the beneficial effect of verapamilin reducing major events in patients recovering from myocardialinfarction is likely to be due to abolishing myocardial ischaemia.