Statins for secondary prevention in elderly patients: a hierarchical bayesian meta-analysis

Abstract

Objectives: This study was designed to determine whether statins reduce all-cause mortality in elderly patients with coronary heart disease.

Background: Statins continue to be underutilized in elderly patients because evidence has not consistently shown that they reduce mortality.

Methods: We searched 5 electronic databases, the Internet, and conference proceedings to identify relevant trials. In addition, we obtained unpublished data for the elderly patient subgroups from 4 trials and for the secondary prevention subgroup from the PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) trial. Inclusion criteria were randomized allocation to statin or placebo, documented coronary heart disease, > or =50 elderly patients (defined as age > or =65 years), and > or =6 months of follow-up. Data were analyzed with hierarchical Bayesian modeling.

Results: We included 9 trials encompassing 19,569 patients with an age range of 65 to 82 years. Pooled rates of all-cause mortality were 15.6% with statins and 18.7% with placebo. We estimated a relative risk reduction of 22% over 5 years (relative risk [RR] 0.78; 95% credible interval [CI] 0.65 to 0.89). Furthermore, statins reduced coronary heart disease mortality by 30% (RR 0.70; 95% CI 0.53 to 0.83), nonfatal myocardial infarction by 26% (RR 0.74; 95% CI 0.60 to 0.89), need for revascularization by 30% (RR 0.70; 95% CI 0.53 to 0.83), and stroke by 25% (RR 0.75; 95% CI 0.56 to 0.94). The posterior median estimate of the number needed to treat to save 1 life was 28 (95% CI 15 to 56).

Conclusions: Statins reduce all-cause mortality in elderly patients and the magnitude of this effect is substantially larger than had been previously estimated.