Egbe AC, et al. - Using the Mayo Adult Congenital Heart Disease (MACHD) database, data were analyzed for 130 patients (42±14 years, 75 men [58%]) with tetralogy of Fallot to assess indications for anticoagulation and the incidence and risk factors for major bleeding complications in these patients. A total of 125 (96%) and 5 (4%) patients received warfarin and direct oral anticoagulants, respectively, for atrial arrhythmias (n=109), mechanical prosthetic valve (n=29), intracardiac thrombus (n=4), pulmonary embolism (n=6), stroke (n=3), and perioperative anticoagulation (n=44). A median follow-up of 74 months revealed the occurrence of 14 minor bleeding events and 11 major bleeding events in eight patients. The identified risk factors for major bleeding events included mechanical prosthesis and hypertension, abnormal renal or liver function; stroke; bleeding history or predisposition; labile international normalized ratio; elderly (>65 years); and drug or alcohol use score ≥2. Patients with major bleeding events (n=6, 75%) vs those without major bleeding events (n=25, 21%) demonstrated higher all-cause mortality. Overall, heterogeneity was observed in the studied congenital heart disease population.