Abstract
We retrospectively compared the incidence of cardiac events in myocardial infarction (MI) patients treated in our departments between 1990 and 1999 with pravastatin or without cholesterol-lowering agents. Our aim was to evaluate the efficacy of pravastatin in the secondary prevention of MI. Cardiac events -defined as fatal or nonfatal recurrent MI, sudden cardiac death, and death from congestive heart failure -occurred in 8 (2.2%) of 356 MI patients treated with pravastatin (17.1 cases/1,000 person • year) and in 39 (5.6%) of 700 MI patients not treated with cholesterol-lowering agents (54.3 cases/1,000 person • year), which represented a significant decline among those taking pravastatin (P < 0.05, odds ratio : 0.39, 95% CI: 0.18-0.84). Likewise, total mortality was significantly lower among patients treated with pravastatin (18 cases, 5.1% ; 38.4 cases/1,000 person • year vs 77 cases, 11.0% ; 107.2 cases/1,000 person • year, P < 0.01, odds ratio : 0.43, 95% CI: 0.25-0.73). Subgroup analysis revealed a significantly lower incidence of cardiac events in the pravastatin group for 6 of the items among 53 patient characteristics, and was lower but not significant for 45 items and was greater but not significant only for 2 items. Furthermore, multivariate analysis confirmed pravastatin to be a useful factor for preventing the occurrence of cardiac events in MI patients (P < 0.05, odds ratio: 0.44, 95% CI: 0.20-0.95), and Kaplan-Meier curves also showed pravastatin to significantly reduce the incidence of both cardiac events and total mortality. These findings are consistent with those previously reported by several large-scale clinical trials carried out in Western countries, and demonstrate that pravastatin is useful for secondary prevention of MI in Japanese patients.
