MedWire News: Pravastatin does not prevent venous thromboembolism (VTE) in elderly people at risk for cardiovascular disease, study findings indicate.
Previous research has suggested that statins might reduce the risk for VTE, however favorable results arising from studies of middle-aged subjects may not be generalizable to elderly people, explain Dilys Freeman (University of Glasgow, UK) and colleagues in the journal BMC Geriatrics.
The researchers therefore analyzed data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) to determine the effect of pravastatin on incident VTE in older people.
The study participants, aged 70-82 years with at least one major risk factor for vascular disease, were randomly assigned to receive pravastatin 40 mg daily (n=2834) or placebo (n=2865) and followed-up for 3.2 years, on average.
During the follow-up period, the incidence of VTE did not differ significantly between the two groups, at 1.0% for participants who received pravastatin versus 0.7% for those who received placebo.
This, say the researchers, is equivalent to a nonsignificant 1.42-fold increase in the risk for VTE among patients who received pravastatin. Adjusting the data for cancer diagnosis - a potential confounder - did not alter the results.
Freeman and co-authors remark that their findings differ from those of the Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) study, which indicated that rosuvastatin significantly reduced symptomatic VTE incidence by 43% in middle-aged subjects with low cholesterol and raised C-reactive protein levels.
The researchers say that the contrasting results may be explained by different characteristics among the populations; PROSPER was an elderly, high-risk population, whereas JUPITER was carried out in a younger, initially healthy population.
Freeman et al also acknowledge that the different results may indicate that the apparent lack of efficacy in VTE prevention is confined to pravastatin alone. "However both pravastatin and rosuvastatin, which was used in JUPITER, are water-soluble statins and thus differences in tissue distribution are unlikely to explain the difference between the effects of these drugs on VTE events," they add.
The researchers conclude that individual data meta-analyses of VTE risk in randomized placebo controlled trials are required.
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