Statins in primary prevention: impact on mortality. A meta-analysis study

INTRODUCTION: An evaluation of the effects of statins on total mortality in the context of primary prevention was carried out, by means of the analysis of data taken from major clinical trials published in the literature. EVIDENCE ACQUISITION: Published systematic reviews were used to identify relevant clinical trials, and data from the third Heart Outcomes Prevention Evaluation study were also used. Meta-analysis was carried out using overall mortality data. EVIDENCE SYNTHESIS: A total of nine clinical trials were selected for further study, and in each of them patients had defined cardiovascular risk factors. Meta-analysis of the overall mortality results of the nine trials showed a significant reduction associated to statin therapy (odds ratio 0.886, 95% confidence limits 0.816-0.963), when compared to the control situation. At least one trial showed a numerical reduction of overall mortality with pravastatin, with atorvastatin and with rosuvastatin. Separate meta-analyses were carried out with clinical trials with each of these three drugs, yielding similar effects: pravastatin - odds ratio 0.852, 95% confidence limits 0.688-1.054; atorvastatin - odds ratio 0.853, 95% confidence limits 0.726-1.002; rosuvastatin - odds ratio 0.870, 95% confidence limits 0.749-1.010. CONCLUSIONS: Statins used in primary prevention lead to a significant decrease in overall mortality. The effects of statins in primary prevention are limited to patients with defined cardiovascular risk factors.