Outcomes of Anticoagulation Therapy in Adults With Tetralogy of Fallot

Background: Available outcomes data for anticoagulation therapy in adults with congenital heart disease (CHD) provide assessment of global risk of this therapy for CHD patients (a heterogeneous population), but the risk of complications for the different CHD diagnoses is unknown. The purpose of the study was to describe the indications for anticoagulation, and the incidence and risk factors for major bleeding complication in adults with tetralogy of Fallot. Methods and Results: We queried Mayo Adult Congenital Heart Disease (MACHD) database for tetralogy of Fallot patients (aged ≥18 years) that received anticoagulation, 1990–2017. Of 130 patients (42±14 years, 75 men [58%]), warfarin and direct oral anticoagulants were used in 125 (96%) and 5 (4%), respectively because 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). The median hypertension, abnormal renal or liver function; stroke; bleeding history or predisposition; labile international normalized ratio; elderly (>65 years); drug or alcohol use score for the entire cohort was 1 (0–2) and 27 (21%) had hypertension, abnormal renal or liver function; stroke; bleeding history or predisposition; labile international normalized ratio; elderly (>65 years); drug or alcohol use score ≥2. There were 14 minor bleeding events (1.6% per year) and 11 major bleeding events (1.3% per year) in 8 patients during median follow-up of 74 months (856 patient-years). Mechanical prosthesis (hazard ratio 1.78, CI 1.29–3.77, P=0.021) and hypertension, abnormal renal or liver function; stroke; bleeding history or predisposition; labile international normalized ratio; elderly (>65 years); drug or alcohol use score ≥2 (hazard ratio 1.41, CI 1.03–3.88, P=0.046) were risk factors for major bleeding events. All-cause mortality was higher in patients with major bleeding events (n=6, 75%) compared with patients without major bleeding events (n=25, 21%), P=0.001. Conclusions: Considering the heterogeneity of the CHD population, data from the current study may be better suited for clinical decision-making in tetralogy of Fallot patients.