"Aspirin for the Prevention of Recurrent Venous Thromboembolism". The New England Journal of Medicine. Published on November 4, 2012.
Links to original sources: Wiki Journal Post Full Journal Article
Does aspirin reduce the recurrence of venous thromboembolism (VTE) in patients who have completed initial anticoagulant therapy after a first episode of unprovoked VTE?
In the ASPIRE study, aspirin did not significantly reduce the rate of recurrent VTE compared to placebo, but resulted in a significant reduction in major vascular events in patients who have completed anticoagulation therapy for a first unprovoked VTE.
Patients with a first episode of unprovoked VTE have a high risk of recurrence when anticoagulants are discontinued. Although aspirin is effective in preventing arterial thrombotic events and primary VTE in high-risk surgical patients, its efficacy in preventing recurrent VTE after the discontinuation of anticoagulants was uncertain.
At the time of publication and the conclusion of the study, guidelines reflecting these results were not specified.
The ASPIRE trial was a multicenter, double-blind, randomized, placebo-controlled trial. It involved 822 patients and had a median follow-up period of 37.2 months.
Inclusion Criteria: - At least 18 years of age - Completed initial anticoagulation therapy (6 weeks to 24 months) after a first unprovoked episode of symptomatic deep-vein thrombosis or acute pulmonary embolism Exclusion Criteria: - VTE occurred more than 2 years before enrollment - Patients with indications or contraindications to aspirin or other antiplatelet therapy, patients who required long-term anticoagulation, or those with other serious conditions
- Aspirin 100 mg daily (n=411) - Placebo (n=411)
Primary Outcome: - Recurrence of VTE. The aspirin group showed a 26% risk reduction compared to placebo, but this was not statistically significant (hazard ratio with aspirin, 0.74; 95% CI, 0.52 to 1.05; P=0.09).
- Major vascular events defined as a composite of VTE, MI, stroke, or cardiovascular death were reduced by 34% in the aspirin group compared to placebo (hazard ratio with aspirin, 0.66; 95% CI, 0.48 to 0.92; P=0.01).
- The study did not reach the initial recruitment goal, resulting in limited power to detect a significant reduction in the primary outcome. - High rate of discontinuation of the study drug may have underestimated the benefits of aspirin therapy.
Funded by National Health and Medical Research Council (Australia), Health Research Council (New Zealand), Australasian Society of Thrombosis and Hemostasis, National Heart Foundation of Australia, and Bayer HealthCare.
Disclosures and detailed information about the ASPIRE trial are available with the full text of the article at NEJM.org.