Novel oral anticoagulant use in adult Fontan patients: A single center experience

Adult Fontan patients are at increased risk for thrombosis and thromboembolic complications leading to increased morbidity and mortality. Most are prescribed antiplatelet or anticoagulant therapy for thromboprophylaxis; novel oral anticoagulants (NOACs) are uncommonly used given lack of data on their use in this population and generalized concerns regarding Fontan patients' abnormal coagulation. We report the largest single-center experience with the use of NOACs for treatment and prophylaxis of thrombosis and thromboembolism in adult Fontan patients.

A retrospective chart review identified 21 patients (11 female, 10 male), median age 33 years (18-50) at first initiation, who were prescribed a NOAC on 27 different occasions. The main indications for anticoagulation were arrhythmia (N = 12), thrombosis (N = 8), and persistent right to left shunts (N = 2); one patient was initially on anticoagulation for arrhythmia but restarted for thrombosis. The most common indications for initiation of a NOAC over warfarin were patient/provider preference (N = 11), labile international normalized ratio (INR) (N = 5), initiation of therapy elsewhere (N = 3), and history of poor clinical follow-up (N = 2). Over a cumulative 316 months of patient therapy, one new thrombotic event was noted. No major or nonmajor bleeding events occurred, and 10 patients experienced minor bleeding that did not require the cessation of therapy. One patient died from multiorgan system failure following an unwitnessed, out of hospital arrest. At present, 10 patients remain on NOAC therapy in the setting of ongoing arrhythmia (N = 4), history of stroke (N = 2), history of pulmonary embolism (N = 2), history of deep vein thrombosis (N = 1), and history of right ventricle thrombus (N = 1).

While our study is limited by size, our results suggest that NOACs may be a non-inferior alternative to traditional anticoagulation and that further study is warranted.