Direct Oral Anticoagulants Compared to Warfarin Early After Cardiac Surgery: A Pilot Randomized Controlled Trial.

Background: The goal was to conduct a pilot randomized controlled trial (RCT) of direct oral anticoagulants (DOACs) early after cardiac surgery to determine the feasibility of a larger RCT. Methods: We conducted an open-label, 2-site, pilot RCT of adults undergoing cardiac surgery with an indication for anticoagulation, excluding mechanical valves and bioprosthetic mitral valve replacements. We randomized patients 1:1 to receive a DOAC or warfarin started during the index hospitalization with a standardized time of postoperative initiation and bridging for high thrombosis risk. The coprimary feasibility outcome goals were recruitment of ≥ 70% eligible patients and adherence to the anticoagulation protocol in ≥ 80% patients. The primary clinical composite outcome included all-cause mortality, major bleeding, stroke, systemic embolism, or pericardial effusion requiring intervention within 3 months. Results: Between October 2022 and February 2024, a total of 547 patients were screened, 163 met inclusion criteria, 104 were randomized, and 100 were analyzed (50 in each group). The median age was 72 years; 22% were female; 54% had preexisting atrial fibrillation; 37% had postoperative atrial fibrillation, with a median Conclusions: Although the a priori recruitment goal was not met, this trial supports the need for and provides valuable insights into key challenges to mitigate, thereby guiding the design of a large, definitive multicentre RCT comparing DOACs vs warfarin in cardiac surgery patients. Clinical Trial Registration: NCT05006287.