A Prospective, Observational, Multicenter Study on the Safety and Efficacy of Apixaban for the Prevention of Thromboembolism in Adults With Congenital Heart Disease and Atrial Arrhythmias: the PROTECT-AR Study

Adult patients with congenital heart disease (ACHD) represent a rapidly growing population due to the progress of surgical techniques and optimal medical management. Non-valvular atrial arrhythmias (AA) carries a significant burden for long-term morbidity and potentially mortality in ACHD patients. AA occur three times more frequently in ACHD compared to the general population. When complicating ACHD, AA convey a twofold increase in the risk for stroke, contributing to an up to 100-fold higher prevalence of stroke in the ACHD population compared to age-matched healthy controls. At present, the European Society of Cardiology (ESC) Guidelines suggest oral anticoagulation (OAC) in all adult patients with AA and intracardiac repair, cyanosis, Fontan palliation, or systemic right ventricle. In the remaining ACHD patients with AA, OAC is suggested if CHA2DS2-Vasc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category) score is ≥1 (Class of recommendation IIa, level of evidence C).

Non-vitamin K oral anticoagulants (NOACs) are increasingly preferred over vitamin-K antagonists (VKAs) in most clinical scenarios due to improved safety (with regard to intracranial and other major bleeding) and efficacy (prevention of embolic stroke or systemic embolism) along with the convenience they offer for patients and physicians (fixed dose, no food and drug interactions, no INR monitoring). On the other hand, scarce data is available on the use of NOAC in ACHD.

In order to address this gap in evidence, we propose a prospective multicenter single arm, observational cohort trial, which will provide data on the efficacy and safety of apixaban used for the prevention of thromboembolism in ACHD patients with AA.