(HealthDay News) – For patients with a first episode of unprovoked venous thromboembolism who complete initial anticoagulant therapy, aspirin does not reduce the recurrence of venous thromboembolism, but does correlate with a reduction in the rate of major vascular events.
Timothy A. Brighton, MB, BS, from the Prince of Wales Hospital in Sydney, Australia, and colleagues conducted a randomized study involving 822 patients who had completed initial anticoagulant therapy after a first episode of unprovoked venous thromboembolism. Participants were allocated to receive 100mg daily aspirin or placebo for up to four years.
During a median of 37.2 months of follow-up, the researchers found that the annual rate of recurrence was 6.5% in patients assigned to placebo versus 4.8% among those assigned to aspirin (hazard ratio for aspirin, 0.74; 95% confidence interval, 0.52–1.05; P=0.09). Aspirin correlated with a reduction in the rate of two prespecified secondary composite outcomes: a 34% reduction in the rate of venous thromboembolism, myocardial infarction, stroke, or cardiovascular death (P=0.01), and a 33% reduction in the rate of venous thromboembolism, myocardial infarction, stroke, major bleeding, or death from any cause (P=0.01). The rates of major or clinically relevant non-major bleeding episodes or serious adverse events were not significantly different between the groups.
“These results substantiate earlier evidence of a therapeutic benefit of aspirin when it is given to patients after initial anticoagulant therapy for a first episode of unprovoked venous thromboembolism,” the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.