Thromboprophylaxis strategies for patients with a Fontan palliation: practice in the NHS

Adults with Fontan palliation face variable risks of thrombosis and bleeding. The optimal thromboprophylaxis strategy remains unclear. There is a balance between the risk of thromboembolism and bleeding with thromboprophylaxis. Recent studies suggest direct oral anticoagulants (DOACs) may provide effective thromboembolism prevention, but concerns regarding bleeding risk, hepatic impairment, and lack of robust data persist. This study investigates thromboprophylaxis practices among UK adult congenital heart disease (ACHD) specialists, focusing on the use of DOACs in Fontan patients. An electronic survey was distributed to UK National ACHD Consultant Group members from February to March 2023. Based on hypothetical clinical scenarios, the survey collected demographic data, familiarity with DOACs, and preferred thromboprophylaxis strategies. Responses were analysed using descriptive statistics to identify patterns in practice. There was a maximum response rate of 42%, with 32 respondents participating, primarily consultants from level 1 ACHD centres. Thromboprophylaxis strategies varied significantly: DOACs, warfarin, and aspirin were used with varying frequency, depending on clinical factors, such as arrhythmias, thrombosis history, and patient-specific challenges. While 35% of respondents were comfortable prescribing DOACs, 42% expressed reservations, citing limited evidence and concerns about risks. This study highlights wide variability in thromboprophylaxis strategies for Fontan patients in the NHS, underscoring significant gaps in evidence. Hepatic considerations, patient-specific challenges, and the lack of DOAC licensing for certain scenarios contribute to the complexity of clinical decision-making. Prospective studies are essential to guide practice, and patient involvement in shared decision-making is critical in the interim.