Statins are beneficial in women for the secondary prevention of some cardiovascular events, but they don’t appear to be any better than placebo at preventing stroke or all-cause mortality, according to a meta-analysis reported in the June 25 issue of Archives of Internal Medicine.
These findings, from a study of 11 randomized, placebo-controlled clinical trials, underscore the differences between men and women in the benefits conferred by statin therapy, said Dr. Jose Gutierrez of the Neurological Institute, Columbia University, New York, and his associates.
Clinical trials have yielded conflicting results concerning the benefit of statins in women known to have cardiovascular disease, compared with those in men. Dr. Gutierrez and his colleagues hoped to clarify the question by restricting their meta-analysis to clinical trials that used randomization and double-blinding; compared statin therapy with placebo rather than usual care or other treatments; included samples of at least 100 subjects; and had follow-up of at least 16 weeks.
The 11 studies they reviewed had a pooled sample size of 43,191 subjects. Even so, only 20% of the subjects were women.
The drugs that were studied included lovastatin, simvastatin, pravastatin, fluvastatin, and atorvastatin.
In the overall study population, statins were effective at preventing any cardiovascular event, all-cause mortality, coronary death, any myocardial infarction, cardiac intervention, and any type of stroke. When the data were stratified by sex, all of these benefits remained significant for men taking statins compared with men taking placebo.
However, women taking statins did not have significantly lower risk than women taking placebo for all-cause mortality or stroke. They did have significantly lower risk for coronary death, any MI, and coronary interventions, the investigators said (Arch. Intern. Med. 2012;172:909-19).
These results did not change in several sensitivity analyses, such as when the analysis was restricted to subjects with the shortest follow-up, the oldest subjects, or subjects taking only hydrophilic statins as opposed to lipophilic statins.
The reason for this discrepancy between men and women is uncertain. “One possibility is that the small sample size of women” – which they characterized as “a major limitation” of their meta-analysis – limited the power of the study to detect significant differences in women, the researchers noted.
“In addition, it is possible that the worse cardiovascular profile of women enrolled in studies, as well as the lower proportion of antiplatelet agent use, could account for some of these differences,” they wrote. Biological differences between the sexes likely play a role as well, as do sex-specific disparities in health care and in biomedical research, they added.
Overall, the study findings support the use of statins in women as in men for the secondary prevention of some cardiovascular events, Dr. Gutierrez and his associates said.
No conflicts of interest were reported.