Abstract 9701: Hemodynamic Parameters Deteriorate Over Time, and Relate to Adverse Clinical Outcomes, in Children and Adults with Fontan Circulation

Abstract

Introduction: In patients with univentricular heart disease, Fontan palliation allows for improved survival. However, Fontan circulatory function deteriorates over time, marked by the onset of functional limitations, morbidities, and mortality. Invasive surveillance offers insights into hemodynamic conditions and may facilitate identification of at-risk patients. Objective: To characterize longitudinal changes in invasive Fontan hemodynamics and evaluate for associations with adverse clinical outcomes. Methods: Single-center retrospective study of serial invasive hemodynamics (≥2 catheterizations) in Fontan patients from 2006-2020. The first and last procedures per patient were analyzed for Fontan pressure, ventricular end diastolic pressure (EDP), cardiac output (CO), systemic (SVR), pulmonary (PVR) and total vascular resistance (TVR). The composite clinical endpoint included death, heart transplant or listing, Fontan takedown, protein losing enteropathy, plastic bronchitis, admission for arrhythmia or congestive heart failure and Fontan revision. Results: Serial hemodynamic evaluations were analyzed in 71 Fontan patients, with first catheterization occurring at median age of 7.1 years (IQR 4.1, 14) and 8.4 years (4.7, 12.3) between assessments. The most common diagnosis was hypoplastic left heart syndrome (45%). Fontan pressure, CO and PVR did not significantly change between assessments, whereas EDP increased by 1.9±3.6 mmHg ( p <0.001). The annualized rate of change in EDP was 0.2±0.14 mmHg/year. SVR (2.0±7.5 U x m 2 , p =0.012) and TVR (2.16 ±7.8 U x m 2 , p =0.031) also increased significantly between assessments. The clinical endpoint was met in 43 (61%) patients and was associated with a greater change in transpulmonary gradient (0.13±1.9 vs -0.87±2.0 mmHg, p =0.046) and Fontan pressure (1.1±5.4 vs -0.7±2.7 mmHg, p =0.066) but not EDP, CO, SVR, PVR or TVR. Conclusion: Over a relatively brief time period, this single-center cohort of Fontan patients demonstrated clinically significant longitudinal increases in EDP, SVR and TVR. Adverse clinical outcomes were common and associated with greater hemodynamic deterioration between assessments. Serial interrogation of Fontan hemodynamics is likely to prove clinically useful.