Anticoagulation After Bioprosthetic Aortic Valve Replacement: Are We Following the Guidelines?

Background: Guideline-directed medication adherence is considered an important quality measure after cardiac surgery. We evaluated compliance with the American College of Cardiology/American Heart Association guidelines for warfarin use after surgical aortic valve replacement (sAVR) using bioprostheses and examined potential variations in anticoagulation practice over time. Methods: Using the OptumLabs Data Warehouse, we investigated adult patients having bioprosthetic sAVR with or without coronary artery bypass (2007-2019). Early postoperative warfarin use was defined as ≥30 days of continuous prescription coverage after sAVR. Results: Among 10 730 adult patients having sAVR, 3071 (28.6%) received warfarin early postoperatively. Median length of warfarin prescription coverage was 4.5 months (interquartile range, 3.0-8.9 months). However, only 11.1% (736/6634) had warfarin prescription coverage of 3 to 6 months in compliance with the most recent guidelines. Yearly warfarin prescription rate did not change significantly during the 13-year period (P = .386). Compared with patients from the non-warfarin group, those receiving warfarin prescriptions were older and more likely to be male and to have atrial fibrillation, congestive heart failure, chronic pulmonary disease, and CHA₂DS₂-VASc score ≥2; warfarin use was also greater in patients receiving prescriptions for other cardiac medications (P < .05). Conclusions: Anticoagulation after sAVR as reflected by warfarin prescriptions may be underused; the rates of warfarin use have not changed in the last decade. Although additional studies are needed to confirm the benefit of early anticoagulation after sAVR, these results indicate that guideline recommendations are not followed by most clinicians. The findings highlight a potentially important area for quality improvement.