San Francisco—Researchers confirmed the safety and efficacy of a lower dose of dabigatran etexilate in elderly hip and total knee replacement surgery patients.
Dabigatran is a new oral thrombin inhibitor recently approved in Europe for the prevention of VTE in patients undergoing this surgery. Ola E. Dahl, MD, of the Thrombosis Research Institute in London, reported the results of a post hoc pooled analysis of 2 pivotal trials comparing dabigatran with enoxaparin at the 50th Annual Meeting of the American Society of Hematology.
Dr Dahl and colleagues analyzed 883 patients older than 75 years who were enrolled in the RE-MODEL and RE-NOVATE trials. Researchers evaluated 220 mg and 150 mg once-daily doses of dabigatran compared to a 40 mg daily dose of enoxaparin.
The primary efficacy endpoint was total number of VTEs and all-cause mortality. Both doses of dabigatran reduced total VTEs compared to enoxaparin, though not significantly.
However, the higher dose of dabigatran produced a significant difference in the secondary endpoint, major VTEs and VTE-related mortality. Four of 216 patients (1.9%) receiving the 220 mg dose had a major VTE, compared with 13 of 218 patients receiving enoxaparin (P=0.045).
The safety endpoint was the difference in major bleeding events, including surgical site bleeding, which accounts for up to 90% of bleeding in these patients. Major bleeding events occurred in 3.7% of the patients receiving dabigatran at 220 mg and 1.4% receiving 150 mg, compared to 2.9% in the enoxaparin group. The study was not powered to show significance in the safety endpoint.
“If you look into the dabigatran regimens versus enoxaparin, you see that we have more efficacious 200 mg dosing with slightly increased bleeding,” Dr Dahl said. “The 150 mg dose has the same efficacy level, but with a little less bleeding. And that is exactly the profile we are looking for in the elderly.”
