Safety and Tolerability of Edoxaban in Filipino Patients With Non-valvular Atrial Fibrillation: A Pilot Post-marketing Surveillance Study

Background: Atrial fibrillation (AF) is a significant driver of cardiovascular mortality and stroke. While the safety and efficacy of the direct oral anticoagulant (DOAC) edoxaban are well-established in global trials, there is limited real-world evidence within the Filipino population. This study evaluated the safety and bleeding rates of edoxaban in routine clinical practice among Filipino patients with non-valvular atrial fibrillation (NVAF). The safety profile of edoxaban is of particular interest in the context of the "East Asian Paradox", where Asian patients exhibit a higher risk of bleeding complications on traditional anticoagulants compared to Western populations. Methods: This was a multicenter, prospective, observational post-marketing surveillance study conducted at six sites in the Philippines, namely, Davao Doctors Hospital, St. Luke's Medical Center (Quezon City and Global City), Makati Medical Center, the Philippine General Hospital, and the Philippine Heart Center, between March 2022 and December 2024. Adult patients (≥21 years) with NVAF and a CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years (doubled), diabetes mellitus, stroke/transient ischemic attack (TIA)/thromboembolism (doubled), vascular disease, age 65-74 years, and sex category (female)) score of ≥1 were prescribed edoxaban (30 mg or 60 mg daily) at the clinician's discretion. Patients were followed for 180 days. The primary endpoints were adverse events (AEs), adverse drug reactions (ADRs), and major bleeding. Results: A total of 72 patients were enrolled; however, one patient (1.4%) did not receive the treatment and was excluded, resulting in a safety analysis population of 71 (mean age: 68.5±10.1 years). The majority of participants were female (50.7%; n=36). Comorbidities were highly prevalent, including hypertension (100%; n=71), coronary artery disease (25.4%; n=18), and heart failure (23.9%; n=17). In this cohort, 35.2% (n=25) were prescribed the 30 mg dose, while 64.8% (n=46) received the 60 mg dose. Over the 180-day observation period, no major bleeding, as well as bleeding requiring medical intervention but not meeting the major criteria, occurred (0%; 95% CI: 0-4.2%). The overall incidence of AEs was low (7%; n=5). One fatal serious AE (acute myocardial infarction) was reported but was determined to be unrelated to the study drug. Conclusion: In this real-world Filipino cohort, edoxaban demonstrated a favorable safety profile with zero major bleeding events over six months of therapy. Despite a high-risk profile and significant comorbidities, these findings align with global phase III and post-marketing data, supporting edoxaban as a safe anticoagulation option for Filipino patients with NVAF.