Perioperative Low Molecular Weight Heparin Bridging in Aortic Mechanical Heart Valve Patients Undergoing Endoscopic Procedures

Background: Optimal management of anticoagulation for patients with aortic mechanical heart valves (MHVs) receiving vitamin K antagonists (VKAs) undergoing gastrointestinal (GI) endoscopic procedures is clinically challenging. The risk of bleeding from an unanticipated polypectomy or biopsy further complicates this issue. Current guidelines on the use of bridging with low-molecular-weight heparin (LMWH) for these procedures are based on low-quality evidence. Methods: We conducted a sub-analysis of a retrospective, multi-center observational study of adult patients with aortic MHVs receiving VKAs who underwent elective GI endoscopies (colonoscopy or upper endoscopy). We included patients who underwent the procedure between July 1, 2020, and July 1, 2023, at 5 centers in Canada and the U.S. Patients with procedures performed on separate days within a 30-day period were excluded. Efficacy and safety outcomes included thromboembolic events, major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) in the 30 days post procedure. Results: A total of 192 endoscopic procedures were analyzed. The median (IQR) patient age was 66 (58.2–72.8) years, and 22% were female. Warfarin was interrupted for 185 (96%) procedures. Among these, 119 (64%) received LMWH bridging: 33 (17%) pre-procedure only, 10 (5%) post-procedure only, and 76 (40%) both pre- and post-procedure. Post-procedure LMWH was initiated a median (IQR) of 1 (1–1) day and discontinued 5 (3–8) days post-procedure. MB occurred in 2 patients (1%), CRNMB in 2 patients (1%), and 1 death (0.5%) was identified; no thromboembolic events occurred. Prior to propensity score matching, post-procedure LMWH with or without pre procedure LMWH was associated with the composite outcome of MB and CRNMB (p = 0.034), although not with MB or CRNMB individually. After stepwise regression and propensity-matched analyses, no significant differences in bleeding outcomes were observed between patients who received LMWH bridging and those who did not. Conclusion: Our findings indicate that while adverse thrombotic events were rare, and the use of post-procedure LMWH bridging was significantly associated with an small absolute increased risk of bleeding, which was not significant after propensity score matching. Larger prospective studies are needed to better inform antithrombotic management guidelines for patients with aortic MHVs undergoing GI endoscopy.