(HealthDay News) – Twenty-eight days of aspirin is non-inferior to, and as safe as, dalteparin, a low-molecular-weight heparin, for the prevention of venous thromboembolism (VTE) after total hip arthroplasty (THA), according to research published in the June 4 issue of the Annals of Internal Medicine.

David R. Anderson, MD, of Capital Health in Halifax, Canada, and colleagues compared extended prophylaxis with aspirin or dalteparin for the prevention of symptomatic VTE after THA. In a multicenter study conducted between 2007 and 2010 in 12 tertiary care orthopedic referral centers in Canada, 786 patients who had elective unilateral THA followed by 10 days of dalteparin prophylaxis were randomly assigned to receive 28 days of extended prophylaxis with either dalteparin (400 patients) or aspirin (386 patients).

The researchers observed VTE in 1.3% of patients receiving dalteparin and 0.3% of patients receiving aspirin. Aspirin therapy was non-inferior (P<0.001), but not superior (P=0.22), to dalteparin therapy for prophylaxis of VTE. There was no significant difference between the groups in bleeding episodes. Because of slow enrollment, the study was terminated prematurely.

“In summary, our study suggests that aspirin is an effective, safe, convenient, and inexpensive alternative to low-molecular-weight heparin for extended thromboprophylaxis after THA,” the authors write.

Pfizer contributed grant money and Bayer provided in-kind support for the study.

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