Oral dabigatran versus enoxaparin for thromboprophylaxis after primary total hip arthroplasty: the RE-NOVATE II randomised trial

BACKGROUND:

Extended thromboprophylaxis after hip arthroplasty reduces the risk of venous thromboembolism (VTE). As oral dabigatran offers practical advantages over subcutaneous enoxaparin in the post-discharge setting, we compared the efficacy and safety of these treatments in this indication.

METHODS:

In this double-blind, non-inferiority trial, 2055 patients undergoing total hip arthroplasty were randomized to treatment for 28 to 35 days with oral dabigatran, 220 mg once-daily, starting with a half-dose 1 to 4 hours after surgery, or subcutaneous enoxaparin 40 mg once-daily, starting the evening before surgery. The primary efficacy outcome was a composite of total VTE (venographic or symptomatic) and death from all-causes. The main secondary composite outcome was major VTE (proximal deep-vein thrombosis, nonfatal pulmonary embolism) plus VTE-related death. The main safety outcome was major bleeding during treatment.

RESULTS:

The median treatment duration was 32 days. In total, 2013 were treated, of whom 1577 operated patients were included in the primary efficacy analysis. The primary efficacy outcome occurred in 7.7% (61 of 792) of the dabigatran group versus 8.8% (69 of 785) of the enoxaparin group, absolute risk difference -1.1% (95% confidence interval [CI], -3.8 to 1.6%); P<0.0001 for the pre-specified non-inferiority margin. The main secondary efficacy outcome occurred in 2.2% (18 of 805) of the dabigatran group versus 4.2% (33 of 794) of the enoxaparin group (absolute risk difference -1.9%, (95% CI,-3.6% to -0.2%; P=0.03). Major bleeding occurred in 1.4% of the dabigatran group and 0.9% of the enoxaparin group (P=0.40). The incidence of adverse events during treatment did not differ significantly between the groups.

CONCLUSIONS:

Extended prophylaxis with oral dabigatran 220 mg once-daily was as effective as subcutaneous enoxaparin 40 mg once-daily in reducing the risk of VTE after total hip arthroplasty. The risk of bleeding and safety profiles were similar.