Use of statins and reduced risk of recurrence of VTE in an older population. A population-based cohort study.

We aimed to determine whether statin use is associated with a decreased risk of recurrent venous thromboembolism (VTE) in older patients. We used a pre-assembled cohort of patients at least 65 years of age diagnosed with incident VTE between January 1, 1994 and December 31, 2004 in the province of Québec, Canada and followed until December 31, 2005. Time-dependent Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) of recurrent VTE associated with current and past use of statins, compared with non-use. The cohort included 25,681 patients with incident VTE. During a mean follow-up of 3.0 years, there were 2343 recurrent VTE events (rate: 3.1 per 100 person-years). Compared with non-use, current use of statins was associated with a decreased risk of VTE recurrence (rates: 1.55 vs 3.47 per 100 per year, respectively; HR: 0.74, 95 % CI: 0.61-0.89), while no association was observed with past use (HR: 0.98, 95 % CI: 0.76-1.25). In a secondary analysis, longer durations of statin use were associated with greater risk reductions (0-6 months, HR 0.82, 95 % CI: 0.67-1.01; 6-12 months, HR 0.62, 95 % CI: 0.43-0.90; ≥ 12 months, HR: 0.50, 95 % CI: 0.33-0.74; p-value for trend ≤ 0.001). The use of statin was associated with a decreased risk of recurrent VTE in older patients. This study supports the need for randomised controlled trials to assess the efficacy and safety of statins in the long-term treatment of VTE.