Low density lipoprotein cholesterol, statins and cardiovascular events: a meta-analysis

A recent meta-analysis of the Cholesterol Treatment Trialists' (CTT) Collaboration comes to the clear conclusion that a reduction in LDL-C using statins of 1 mmol/l (39 mg/dl) leads to a decrease in overall mortality by 12%, in coronary mortality by 19% and in the incidence of strokes by 17%, independent of the LDL-C level prior to the start of treatment. We conducted a systematic review retrieving 18 studies with a total of 116,343 [corrected] participants. Differences in average LDL-C reductions between the intervention and control groups during the follow-up and relative risks according to different clinical endpoints were extracted from the original publications. Metaregression analyses showed that reduction in LDL-C accounted for more than 75% of the variance in risk reductions for overall mortality and cardiovascular endpoints. On the basis of our estimates, a reduction in LDL-C of 1 mmol/l (39 mg/dl) leads to reductions in overall mortality, coronary mortality, incidence of non-fatal myocardial infarction, the combination of coronary mortality and non-fatal myocardial infarction, stroke and any vascular event by 15% (95% CI: 11-20%), 24% (95% CI: 20-28%), 27% (95% CI: 20-32%), 25% (95% CI: 22-29%), 24% (18-29%) and 22% (95% CI: 19-26%), respectively. We conclude that the extent to which statins lower LDL-C is strongly related to the improvement of clinical outcomes achieved by this class of drugs.