Safety of direct oral anticoagulants in surgical bioprosthetic heart valves: a paediatric institution's experience.

Surgical pulmonary valve replacement is commonly required to palliate patients with CHD affecting the right ventricular outflow tract; however, concerns remain about mid- and long-term durability. Post-operative short-term anticoagulation has been hypothesised to improve valve durability. This is a single-centre, retrospective study of paediatric patients who underwent surgical pulmonary valve replacement and received a direct oral anticoagulant in addition to aspirin post heart valve insertion. The primary objective was a composite safety score consisting of clinically relevant non-major bleeding, major bleeding, bleeding-related readmission, and medication discontinuation. The study analysed 34 patients with a median age 14 years (Interquartile range (IQR): 11, 15) and weight 45 kg (IQR: 35, 55). Ten patients met the composite endpoint (10/34, 29%), with 4 patients experiencing major bleeding (4/34, 12%), 6 experiencing clinically relevant non-major bleeding (6/34, 18%), and 3 patients being readmitted within 90 days of surgical pulmonary valve replacement for bleeding (3/29, 8.8%) resulting in 10 patients discontinuing medication early (10/34, 29%). Lower weight was identified as a significant risk factor for adverse event development (p = 0.04). We observed a higher overall bleeding rate, driven predominately by clinically relevant non-major bleeding events, than other studies using short-term anticoagulation after surgical pulmonary valve replacement. Additional studies should be aimed at evaluating the dosing and safety of direct oral anticoagulants in children in the post-operative period.