Clinical outcomes in statin treatment trials - A meta-analysis

Objective: To determine the risk of cardiovascular events and death in pati ents receiving statin treatment for cholesterol regulation. Methods: Systematic review and meta-analysis of all randomized controlled t rials that were published as of April 15, 1997. Primary or secondary preven tion trials or regression trials were eligible. Main Outcome Measures: All-cause mortality, fatal myocardial infarction (MI ) or stroke, nonfatal MI or stroke, angina, and withdrawal from the studies . Both random- and fixed-effects models were run for the outcomes of intere sts, and results are expressed as odds ratios (ORs). Sensitivity analyses t ested the impact of the study type and duration, statin treatment type, and control arm event rates. Intent-to-treat denominators were used whenever t hey were available, and the number needed to treat was calculated when appr opriate. Results: Seventeen studies (21303 patients) were included (2 secondary prev ention studies, 5 mixed primary-secondary prevention population studies, an d 10 regression trials). Treatment groups included lovastatin (t = 5), prav astatin (t = 10), and simvastatin (t = 3). For all-cause mortality, the OR was 0.76 (95% confidence interval [ CI], 0.67-0.86) in favor of receiving s tatin treatment; for fatal MI, the OR was 0.61 (95% CI, 0.48-0.78); for non fatal MI, the OR was 0.69 (0.54-0.88); for fatal stroke, the OR was 0.77 (9 5% CI, 0.57-1.04); for nonfatal stroke, the OR was 0.69 (95% CI, 0.54-0.88) ; and for angina, the OR was 0.70 (95% CI, 0.65-0.76). Conclusions: Patients who received statin treatment demonstrated a 20% to 3 0% reduction in death and major cardiovascular events compared with patient s who received placebo. This advantage was generally present across study t ypes and statin treatment types and for patients with less severe dyslipide mias. The benefit in clinical outcomes was noticeable as early as 1 year.