Commentary on: Rivaroxaban for Venous Thromboembolism Prophylaxis in Abdominoplasty: A Multicenter Experience.

Abstract

We appreciate the opportunity to review this article by Dr Hunstad and his colleagues.1 The authors report on observed rates of venous thromboembolism (VTE) and reoperative hematoma in a case series of 132 abdominoplasty patients who received chemoprophylaxis with rivaroxaban 10 mg daily beginning 12 hours after surgery and continuing for ≥7 days. The oral direct inhibitors of factor Xa (FXa) are the newest class of anticoagulant drugs and have ever-expanding indications. Factor X can be activated (to FXa) via either the intrinsic or extrinsic clotting pathways. FXa promotes conversion of prothrombin to thrombin, resulting in clot formation. Enoxaparin accelerates the activity of antithrombin, which accelerates the rate of inactivation of FXa. Inactivation of FXa subsequently decreases thrombin generation. Fondaparinux, the effect of which is largely mediated through FXa inhibition (with some inhibition of Factor IXa), is also an effective anticoagulant. Clinical utility of fondaparinux identified FXa as an appealing target for anticoagulants because it represents a unifying pathway of the extrinsic and intrinsic clotting pathways.2 Rivaroxaban is an oral direct inhibitor of FXa. Rivaroxaban is approved by the United States Food and Drug Administration for prevention of stroke and systemic embolism for patients with nonvalvular atrial fibrillation, treatment of acute VTE, long-term prevention of recurrent VTE after an initial 6 months of therapy, and prevention of VTE after total knee or hip arthroplasty. Approval was based on large phase III trials showing noninferior or superior efficacy and similar or reduced rates of major, intracranial, and fatal bleeding compared with conventional anticoagulants (ie, enoxaparin and/or warfarin).3-7 For patients undergoing total knee arthroplasty, rivaroxaban 10 mg daily reduced the primary outcome of VTE and death compared with enoxaparin 40 mg daily (9.6% vs 18.9%, P < .001) without increased bleeding.6 Similar findings were observed after …