Randomized Controlled Trial of New Oral Anticoagulants Versus Warfarin for Post Cardiac Surgery Atrial Fibrillation: The NEWAF Trial.

Abstract

OBJECTIVE To determine whether anticoagulation for new onset atrial fibrillation (AF) with rivaroxaban decreases length of stay compared to warfarin. SUMMARY OF BACKGROUND DATA Direct Oral Anticoagulants (DOACs) have been shown to be noninferior to warfarin for stroke prevention in nonsurgical patients with atrial fibrillation. There are no published randomized trials comparing DOACs to warfarin in cardiac surgery patients, and DOACs are yet to be widely adopted in this population. METHODS In a pragmatic, prospective, clinical trial, 100 patients with new-onset AF after cardiac surgery were randomized to receive rivaroxaban (n=50) or warfarin (n=50). Patients were followed for 30 days post-discharge, with patient-reported outcomes assessed two weeks after discharge using the Perception of Anticoagulant Treatment Questionnaire and the EuroQol-5D-3L survey. RESULTS The primary endpoint, length of stay (LOS) from day of surgery to discharge (days, IQR), was 7 (6-9) for rivaroxaban and 8 (6-9) for warfarin (P=0.460). LOS from initiation of anticoagulation to discharge was 2 (1-4) days for rivaroxaban and 2 (1-3) days for warfarin (P=0.738). The mean INR at discharge in the warfarin group was 1.68 (SD 0.5). No major bleeding events, strokes, or other arterial thromboembolism events occurred in either group. Minor bleeding events were reported in 3/50 (6%) patients in the rivaroxaban group versus 1/50 (2%) in the warfarin group (P=0.617), none of which required blood transfusion. One patient (2%) in the rivaroxaban group developed a pericardial effusion requiring drainage, compared to none in the warfarin group (P=1.000). Patients taking rivaroxaban reported significantly higher scores for convenience (P<0.001) and better overall perception of their anticoagulation experience (P=0.006), though both groups reported similar treatment satisfaction (P=0.494). Mobility issues were reported by 42.2% of patients taking rivaroxaban compared to 18.6% of those taking warfarin (P=0.021). All outcomes were consistent in both the intention-to-treat and as-treated populations. CONCLUSIONS Treatment with rivaroxaban in new-onset atrial fibrillation after cardiac surgery did not decrease length of stay compared to warfarin. However, patients treated with rivaroxaban reported significantly better convenience and a more favorable overall perception of their anticoagulation experience compared to warfarin. Given similar safety profiles, these findings support incorporating rivaroxaban as an option for shared-decision-making when selecting anticoagulation therapy for this patient population.