Statins for acute coronary syndrome.

BACKGROUND: The early period following the onset of acute coronary syndromes (ACS) represents a critical stage of coronary heart disease with a high risk for recurrent events and deaths. The short-term effects of early treatment with statins in patients suffering from ACS on patient-relevant outcomes are unclear.

OBJECTIVES: To assess the benefits and harms of early administered statins in patients with ACS from randomized controlled trials (RCTs).

SEARCH STRATEGY: We searched CENTRAL, MEDLINE, EMBASE, and CINAHL (to 1 February 2010). No language restrictions were applied. We supplemented the search by contacting experts in the field, by reviewing reference lists of reviews and editorials on the topic, and by searching trial registries.

SELECTION CRITERIA: RCTs comparing statins with placebo or usual care, initiation of statin therapy within 14 days following the onset of ACS, and follow-up of at least 30 days reporting at least one clinical outcome.

DATA COLLECTION AND ANALYSIS: Two authors independently assessed study quality and extracted data. We pooled treatment effects and calculated risk ratios (RRs) for all outcomes in the treatment and control groups using a random effects model.

MAIN RESULTS: Eighteen studies (14,303 patients) compared early statin treatment versus placebo or usual care in patients with ACS. Compared to placebo or usual care, early statin therapy did not decrease the combined primary outcome of death, non-fatal myocardial infarction (MI), and stroke at one month (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.80 to 1.08) and four months (RR 0.93, 95% CI 0.81 to 1.06) of follow-up. There were no statistically significant risk reductions from statins for total death, total MI, total stroke, cardiovascular death, revascularization procedures, and acute heart failure at one month and at four months, although there were favorable trends related to statin use for each of these endpoints. The incidence of episodes of unstable angina was significantly reduced at four months following ACS (RR 0.76, 95% CI 0.59 to 0.96). There were nine individuals with myopathy (elevated creatinine kinase levels > 10 times the upper limit of normal) in statin treated patients (0.13%) versus one (0.015%) in the control groups. Serious muscle toxicity was mostly limited to patients treated with simvastatin 80 mg.

AUTHORS' CONCLUSIONS: Based on available evidence, initiation of statin therapy within 14 days following ACS does not reduce death, myocardial infarction, or stroke up to four months, but reduces the occurrence of unstable angina at four months following ACS.