Comparison of atorvastatin 80 mg/day versus simvastatin 20 to 40 mg/day on frequency of cardiovascular events late (five years) after acute myocardial infarction (from the Incremental Decrease in End Points through Aggressive Lipid Lowering [IDEAL] trial)

Abstract

Previous studies have demonstrated that benefits of intensive statin therapy compared to standard statin therapy begin shortly after an acute event and are continued up to 2 years of follow-up. However, whether efficacy and safety of intensive statin therapy in patients with a recent cardiac event are maintained in longer-term follow-up has not been evaluated. We conducted a post hoc analysis of a subgroup of 999 patients who had a first acute myocardial infarction (MI) <2 months before randomization in a prospective, open-label, blinded end-point evaluation trial of 8,888 patients with a history of MI that compared intensive statin therapy (atorvastatin 80 mg) to standard statin therapy (simvastatin 20 to 40 mg) over approximately 5 years of follow-up. We analyzed the same composite end point used in the Pravastatin or Atorvastatin Evaluation and Infection Therapy (PROVE IT) trial (death, MI, hospitalization for unstable angina, revascularization, and stroke). Rates of the composite end point were 44.7% (n = 226) in the simvastatin group and 37.9% (n = 187) in the atorvastatin group (hazard ratio 0.82, 95% confidence interval 0.67 to 0.99, p = 0.04). Although statistical power was smaller than that of the PROVE IT trial, the relative risk decrease observed at 5 years is consistent with that in the 2-year follow-up in PROVE IT. The 2 treatment regimens were well tolerated. In conclusion, our analysis provides support for the strategy of placing patients with recent MI on intensive statin therapy and maintaining the high dose over the long term, beyond 2 years.