Twice-daily low-dose aspirin is similar to enoxaparin for thromboprophylaxis after inpatient treatment for fracture (PREVENT CLOT)

Référence

Major Extremity Trauma Research Consortium (METRC); O'Toole RV, Stein DM, et al. Aspirin or low-molecular-weight heparin for thromboprophylaxis after a fracture. N Engl J Med 2023;388(3):203-213.

Sommaire

This large pragmatic trial included 12,211 adults with an extremity fracture treated operatively, or a pelvic or acetabular fracture treated with or without surgery. The patients were randomized to receive aspirin 81 mg twice daily or low-molecular-weight heparin (enoxaparin) 30 mg twice daily. The patients received the assigned medication while in the hospital, and then followed their hospital's postdischarge thromboprophylaxis protocol. Patients with fractures of the hands or feet, who had already received 3 or more doses of thromboprophylaxis, or who were admitted more than 48 hours after the injury were excluded. Those taking an anticoagulant on admission or with a history of venous thromboembolism in the previous 3 months were also excluded. At baseline, the mean age of participants was 45 years, 62% were men, and 20% were Black. The most common site of injury was the lower extremity, with 67% having only a lower extremity fracture. Groups were balanced at the start of the study and analysis was by intention to treat. The primary outcome of 90-day all-cause mortality occurred in 0.78% in the aspirin group and 0.73% in the enoxaparin group (95% CI for the difference -0.27 to 0.38). There was no difference in the likelihood of any pulmonary embolism (1.49% in each group), but there were slightly more deep vein thromboses in the aspirin group (2.51% vs 1.71%; 95% CI for difference 0.28 - 1.31; number needed to treat to harm = 125), though most of the increase was in distal clots. There was also no difference in the rate of bleeding complications, infections, or wound complications.