Physician Perception of Fontan Failure, "Acceptable" Hemodynamics, Assessment, and Indications for Intervention-Results of a Multinational Survey.

Background: Patients with complex congenital heart disease unfit for biventricular repair are often palliated with Fontan circulation (FC), which obviates the need for a subpulmonary ventricle. This approach has led to high survival rates, with over 80% of patients expected to live beyond 30 years. Despite increasing patient numbers and existing guidelines, there are no standardized hemodynamic parameters defining Fontan failure, resulting in considerable variability in management practices. This pilot project aimed to assess real-world practices in FC patient management, particularly in surveillance, defining Fontan circulatory failure, and determining treatment thresholds. Methods: A cross-sectional survey with 10 multiple-choice questions and optional free-form responses was distributed globally to congenital heart disease cardiologists through 2 academic centers. Conducted from January to December 2021, the survey targeted clinicians managing adult FC patients. Results: Of 310 invited cardiologists, 170 (55%) participated, including 27% from the United States, 22% from Canada, and 20% from the United Kingdom. Respondents included pediatric (37%), adult congenital (47%), and dual trained adult/pediatric cardiologists (14%), mostly in academic settings (94%). Variability existed in defining FC failure, with markers such as protein-losing enteropathy (74%), fatigue/dyspnea (62%), and elevated Fontan pressure (58%) commonly cited. Responses differed on defining elevated Fontan pressure, with 53% selecting >15 mm Hg, 33% >18 mm Hg, and 14% >20 mm Hg. Ninety-one percent prescribed pulmonary vasodilators, though indications and thresholds varied. Conclusion: Substantial heterogeneity in FC patient management currently exists, underscoring the need for standardized hemodynamic parameters.