Mode of death and predictors of mortality in adult Fontan survivors: A Japanese multicenter observational study

Background: Mortality rates may be high in adult Fontan patients; however, the clinical determinants remain unclear. Purpose: We conducted a prospective multicenter study of adult Fontan survivors to determine the 5-year mortality rate and clarify the determinants. Method and results: We followed 600 adult Fontan survivors from 40 Japanese institutions (307 men, 28 ± 7 years old, follow-up: 18 ± 6 years). The New York Heart Association (NYHA) functional class I and II was 51% and 42%, respectively. During the follow-up period of 4.1 ± 1.6 years, 33 patients died, and the 5-year survival rate was 93.5%. The mode of death was heart failure in 11 patients (34%), arrhythmia or sudden death in 8 (24%), cancer in 5 (15%), perioperative problems and hemostatic problems in 4 each (12% for each), and infection in 1 (3%). Left isomerism, prior hospitalization, protein losing enteropathy (PLE), pulmonary arteriovenous fistulae, NYHA functional class, impaired hemodynamics, hyponatremia, hepatorenal dysfunction, and use of diuretics were associated with a high mortality rate (p < 0.05–0.0001). Further, PLE (hazard ratio [HR]: 14.4), left isomerism (HR: 3.5), and NYHA (HR: 2.4) independently predicted a high 5-year high mortality (p < 0.05 for all). The incidence of cancer-related mortality increased markedly with age >40 years. Conclusions: Majority of the Japanese adult Fontan survivors had good functional status, with an acceptable 5-year survival rate. However, the significant prevalence of non-cardiac mortality highlights Fontan pathophysiology as a multi-organ disease that requires a multidisciplinary management strategy to improve the long-term outcome.