The New England Journal of Medicine has published the results of a randomised controlled study that aimed to quantify any benefits of rosuvastatin in the prevention of venous thromboembolism (VTE). The results have been reported in the general media (BBC).
The study recruited 17,802 participants with a low-density lipoprotein (LDL) cholesterol below 3.4 mmol/L and a high-sensitivity C-reactive protein (hs-CRP) levels of 2.0mg/L or above. Participants were randomly assigned to treatment with rosuvastatin 20mg daily or placebo. Median follow up was approximately 2 years. The primary outcome was symptomatic venous thromboembolism or pulmonary embolism.
During the study the primary outcome occurred in 34 patients taking rosuvastatin and 60 patients taking placebo. This represents a 43% relative risk reduction (Hazard ratio 0.57, 95% Confidence interval 0.37 to 0.86; P=0.007) from a baseline risk of 0.32 events per 100 patient-years based on the placebo arm risk.
44 instances of the primary outcome were classified as 'provoked' because they were associated with cancer or recent trauma, hospital admission or surgery. The risk reduction was similar in both the 'provoked' and 'unprovoked' subgroups. There was a decreased tendency to pulmonary embolism in the rosuvastatin group but this was not statistically significant.
Although these findings are interesting, further research is required to quantify potential benefits in patients at higher risk of venous thromboembolism. In addition, hs-CRP tests are currently not widely available and the clinical significance of hs-CRP results lacks consensus.
Action: Statins should not be routinely used with the exclusive aim of preventing VTE. Efficacy and safety has not been demonstrated in individuals at high risk.
The absolute risk reduction over the 1.9 years median follow up works out as 0.2921%. This means that 342 people would have to be treated with rosuvastatin 20mg instead of placebo for 1.9 years to prevent one VTE at a cost of just over £400,000.