Statins and prevention of venous thromboembolism: Myth or reality?

The pleiotropic effects of statins, beyond their cholesterol-lowering properties, are much debated. In primary prevention, several observational cohort and case-control studies appear to show that statins reduce the incidence of venous thromboembolism by about 30%. In a single randomized placebo-controlled clinical trial (JUPITER), which included 17,000 patients, rosuvastatin 20mg/day reduced the risk of venous thromboembolism by 43%. However, these patients were at low risk of venous thromboembolism, and the frequency of the event was, in principle, low. In secondary prevention, several observational studies and post-hoc analyses of randomized clinical trials have suggested that statins may prevent recurrence of venous thromboembolism. However, none of these studies had enough scientific weight to form the basis of a recommendation to use statins for secondary prevention. The putative preventive effect of statins appears to be independent of plasma cholesterol concentration and could be a pharmacological property of the statin class, although a dose-effect relationship has not been demonstrated. The mechanism through which statins might prevent venous thrombosis is thought to involve their anti-inflammatory and antioxidant effects or perhaps a more specific action, by blocking the degradation of antithrombotic proteins. A mechanism involving the action of statins on interactions between risk factors for atherosclerosis and venous thromboembolism is supported by some studies, but not all. In the absence of firm evidence, statins cannot currently be recommended for primary or secondary prevention of venous thromboembolism.