The Impact of Fontan Circulatory Failure on Heart Transplant Survival: A 20-Center Retrospective Cohort Study

Abstract

Background: Fontan circulatory failure (FCF) is a chronic state in palliated single ventricle heart disease with high morbidity and mortality rates, including heart failure, multisystem end-organ disease, and need for heart transplant. Specific FCF morbidities have not been rigorously defined, limiting study of how FCF morbidities affect pre-heart transplant and post-heart transplant outcomes. We hypothesized that FCF-related morbidities affect survival from heart transplant waitlisting through 1 year after heart transplant.

Methods: This 20-center, retrospective cohort study collected demographic, medical/surgical history, waitlist, and peri- and post-heart transplant data, and a priori defined FCF-specific morbidities, in Fontan patients who were listed for heart transplant from 2008 through 2022. Univariate 2-group statistics compared surviving individuals with those who died anytime from waitlisting to 1 year after heart transplant, died on the waitlist, or underwent transplant and died within 1 year after transplant. Using covariates from both univariate analyses, multivariable logistic regression determined the primary study outcome of independent FCF risk factors for death between waitlist and 1 year after heart transplant.

Results: Of 409 waitlisted patients, 24 (5.9%) died on the waitlist. Of the 341 (83.4%) who underwent transplant, 27 (8.5%) did not survive to 1 year. Univariate risk factors for waitlist death included higher aortopulmonary collateral burden, >1 hospitalization in the previous year, younger age, sleep apnea, higher New York Heart Association class, nonenrollment in school or work, and single-parent home. Risk factors for 1-year post-heart transplant mortality included hypoplastic left heart syndrome diagnosis, patent fenestration, anatomic Fontan obstruction, clinical cyanosis (pulse oximetry <90%), polycythemia, portal variceal disease, mental health condition requiring treatment, and higher human leukocyte antigen class II panel reactive antibody. Of the patients not surviving from waitlisting to 1 year after heart transplant, independent risk factors for death included >1 hospitalization in the year before waitlisting (adjusted odds ratio, 2.0 [95% CI, 1.0-4.1]; P=0.05) and clinical cyanosis (adjusted odds ratio, 5.0 [95% CI, 1.8-13.4]; P=0.002).

Conclusions: Patients with Fontan palliation selected for heart transplant have substantial mortality rates from waitlisting through transplant. Among FCF-specific morbidities, cyanosis is associated with worsened survival and necessitates further study. Clinical morbidity of any type requiring repeated hospital admission also should prompt consideration of heart transplant.

Keywords: Fontan procedure; heart defects, congenital; transplantation.