Early statin therapy in acute coronary syndromes: the successful cycle of evidence, guidelines, and implementation

Abstract

That statins should be prescribed for patients before hospital discharge after an episode of acute coronary syndrome (ACS) is a Level of Evidence: 1A recommendation of the American College of Cardiology/American Heart Association Joint Task Force. This level of recommendation is based upon 2 clinical trials: the MIRACL (Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering) and PROVE-IT (Pravastatin or Atorvastatin Evaluation and Infection Therapy) trials. In the MIRACL trial, 3,086 patients with unstable angina or non-Q-wave myocardial infarction were randomized within 4 days of the event to atorvastatin 80 mg/day or to placebo and followed for 16 weeks. The primary composite end point occurred in 14.8% of atorvastatin patients and 17.4% of placebo patients, a 16% relative risk reduction (p = 0.048). In the PROVE-IT trial, 4,162 patients hospitalized with an ACS within the preceding 10 days were randomized to atorvastatin 80 mg/day or pravastatin 40 mg/day and were followed for a mean of 24 months. The primary event rate was 22.4% in the atorvastatin group and 26.3% in the pravastatin group, a 16% relative risk reduction (p = 0.005). A strong trend toward a reduction in total mortality was seen in the atorvastatin group (2.2% vs. 3.2%, p = 0.07). Using a composite end point of death, myocardial infarction, and rehospitalization for ACS, the difference between the treatment groups is already statistically significant at 30 days and remains so throughout the follow-up period. Comprehensive treatment programs in ACS patients that include initiation of statins before hospital discharge have been shown to improve outcomes such as recurrent myocardial infarction and total mortality at 1 year. Guidelines prove their utility when their implementation improves outcomes across a broad population at risk, such as in this instance.