Association between Statin and Fibrate Use and Venous Thromboembolism: A Case-Control Study.

Background:

Previous studies of selected patients have suggested a reduction in the risk of venous thromboembolism (VTE) with the use of statins, and no effect of fibrates.

Objective:

To evaluate the influence of statin and fibrate use on the risk of venous thromboembolic events.

Design:

Case-control study (EDITH) designed to investigate genetic and environmental risk factors of VTE.

Setting:

Brest University Hospital.

Participants:

857 patients consecutively hospitalized for a documented venous thromboembolic event were included between May 2000 and May 2004. Controls were matched on age, sex and the main risk factors of VTE (cancer, surgery, pregnancy…).

Results:

The mean age of patients was 67.7 year. No significant difference was found between cases and controls concerning the main characteristics, except for smocking and body mass index. Controls had more often previous vascular events (coronary heart disease, stroke or arteriopathy of the lower limbs) than cases but the difference was no significant. Statin use was associated with a significant decreased risk of VTE (odds ratio (OR) = 0.58; 95% confidence interval (CI), 0.41–0.82), whereas fibrate use was associated with a significant increased risk of VTE (OR = 1.60; 95% CI, 1.09–2.34). After adjustment on the main confounding factors including aspirin use and cardiovascular disease, these associations remained significant. Among pleiotropic effects of statins, some antithrombotic mechanisms could be proposed to explain their possible protective effect. Concerning the possible negative effect of fibrates, some authors found that the most prescribed fibrates, but not statins, caused hyperhomocysteinemia. In our study, analyses of homocysteinemia are ongoing.

Conclusion:

In this case-control study of hospitalized patients, statin use was associated with a significant decreased risk of VTE, whereas fibrate use was associated with a significant increased risk. Homocysteinemia may be involved in the difference between the effects of these two categories of lipid-lowering drugs on VTE. Because our study was observational, the protective effect of statins as regards the risk of VTE remains questionable and further prospective studies are needed.