Influence of warfarin on cardiac and cerebrovascular events following bioprosthetic aortic valve replacement: A nationwide cohort study

Efficacy and Safety of Edoxaban in Anticoagulant Therapy Early After Surgical Bioprosthetic Valve Replacement: Rationale and Design of the ENBALV Trial

BACKGROUND AND PURPOSE

Anticoagulant therapy with vitamin K antagonists is recommended within 3 to 6 months after bioprosthetic valve replacement to prevent thromboembolic events. However, data regarding whether direct oral anticoagulants can be an alternative to warfarin in such patients are limited. The purpose of this study is to compare the efficacy and safety of edoxaban versus warfarin within 3 months after bioprosthetic valve replacement.

METHODS

The ENBALV trial is an investigator-initiated, phase 3, randomized, open-label, multicenter study. It involves patients aged 18 to 85 years undergoing bioprosthetic valve replacement at the aortic and/or mitral position. They are randomized 1:1 to receive either edoxaban or warfarin. Administration of edoxaban or warfarin is to be continued for 12 weeks after surgery. The primary outcome is the occurrence rate of stroke or systemic embolism at 12 weeks after surgery. The net clinical outcome is a composite of stroke, systemic embolism, or major bleeding, which is included in the secondary outcomes.

CONCLUSION

The ENBALV trial demonstrates the efficacy and safety of edoxaban compared with warfarin in patients early after bioprosthetic valve replacement, including patients with sinus rhythm, which will bring a significant benefit to patients in clinical practice.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCT) 2051210209. 30 Mar 2022 https://jrct.niph.go.jp/latest-detail/jRCT2051210209 .

Benefit of Anticoagulation Early After Surgical Aortic Valve Replacement Using Bioprosthetic Valves

OBJECTIVE

To compare all-cause mortality and thromboembolic events in patients undergoing surgical aortic valve replacement (sAVR) receiving anticoagulation with warfarin versus patients with no systemic anticoagulation.

PATIENTS AND METHODS

Using data from the OptumLabs Data Warehouse, we investigated adult patients having bioprosthetic sAVR with or without coronary artery bypass from January 1, 2007, through December 31, 2019. Patients were classified into groups of nonwarfarin or warfarin (≥30 days of continuous prescription coverage after sAVR). One-to-one propensity score (PS) matching was used to adjust for group differences.

RESULTS

Of 10,589 patients having sAVR, 7659 (72.3%) were in the nonwarfarin group and 2930 (27.7%) were in the warfarin group. After PS matching, 2930 pairs of patients were analyzed. Median follow-up was 4.1 months (interquartile range [IQR], 2.6-7.4 months) for the warfarin group and 21.3 months (IQR, 7.8-24.0 months) for the nonwarfarin group. Overall mortality was lower for the warfarin group than for the nonwarfarin group (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.47 to 1.00; P=.047), and there was a trend toward decreased cumulative incidence of thromboembolic events (subdistribution HR [SHR], 0.62; 95% CI, 0.35 to 1.07; P=.09). Cumulative incidence of major bleeding events was higher for the warfarin group vs the nonwarfarin group (SHR, 1.94; 95% CI, 1.28 to 2.94; P=.002). Results were similar in a subgroup analysis of patients undergoing isolated sAVR.

CONCLUSION

During the prescription coverage period, warfarin use after bioprosthetic sAVR was associated with lower all-cause mortality and decreased risk of thromboembolism compared with not receiving warfarin. However, warfarin use was associated with an increased risk of major bleeding events.