TEMPORAL PATTERN OF THE EFFECT OF VERAPAMIL ON MYOCARDIAL REINFARCTION

The purpose of this study was to compare the effects of verapamil on e arly versus late reinfarction after an index myocardial infarction. A total of 1775 consecutive patients <76 years of age, with acute myocar dial infarction, included in the Danish Verapamil Infarction Trial II, were followed for 18 months. Reinfarctions during the observation per iod were retrospectively divided into the 50% earliest occurring and t he 50% latest occurring (early and late reinfarction, respectively). C ox regression analysis was applied to assess the significance of clini cal baseline variables and treatment group (verapamil vs. placebo) on early, late, and total reinfarction. One hundred and ninety-one reinfa rctions were registered during the 18-month observation: 96 in the fir st 5 months (early) and 95 in the last 13 months (late). On univariate analysis verapamil significantly reduced the rate of total reinfarcti on (P = 0.04, hazard ratio [HR] = 0.77; 95% confidence Interval [CI] 0 .58-1.03) and early reinfarction (P = 0.007, HR 0.56; 95% CI 0.37-0.86 ), but not late reinfarction (P = 0.99, HR = 1.05; 95% CI 0.70-1.56). In a multivariate model, only the rate of early reinfarction was reduc ed by verapamil (P = 0.012, HR = 0.59, 95% CI 0.39-0.90). Additionally , predictors of early and late reinfarction were quite different in th is model. After an index myocardial infarction verapamil reduces the r ate of early but not late reinfarction.