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The Impact of Fontan Circulatory Failure on Heart Transplant Survival: A 20-Center Retrospective Cohort Study
Kurt R Schumacher1, David N Rosenthal2, Adriana Batazzi1
1Congenital Heart Center, Department of Pediatrics, University of Michigan, Ann Arbor (K.R.S., A.B., S.Y., G.R., M.K.C.).
Insights
Fontan circulatory failure patients awaiting heart transplant face high mortality. Cyanosis and prior hospitalizations are key risk factors for death from waitlisting to one year post-transplant.
Area of Science:
- Cardiology
- Pediatric Cardiology
- Transplant Surgery
Background:
- Fontan circulatory failure (FCF) is a severe complication of single ventricle heart disease, leading to high morbidity and mortality.
- Existing definitions of FCF morbidities are insufficient, hindering research into their impact on heart transplant outcomes.
- Understanding FCF-specific risks is crucial for improving survival in patients undergoing heart transplantation.
Purpose of the Study:
- To investigate the impact of Fontan circulatory failure-related morbidities on survival.
- To identify specific risk factors for mortality from heart transplant waitlisting through one year post-transplant.
Main Methods:
- A retrospective cohort study involving 20 centers and 409 Fontan patients listed for heart transplant (2008-2022).
- Data included demographics, medical history, waitlist status, and peri- and post-transplant information.
- Multivariable logistic regression identified independent risk factors for death.
Main Results:
- Mortality rates were substantial: 5.9% died on the waitlist, and 8.5% died within one year post-transplant.
- Independent risk factors for death between waitlisting and one year post-transplant included prior hospitalizations and clinical cyanosis.
- Specific morbidities like hypoplastic left heart syndrome, Fontan obstruction, and portal variceal disease were associated with post-transplant mortality.
Conclusions:
- Patients with Fontan palliation undergoing heart transplant have significant mortality risks.
- Clinical cyanosis is a critical FCF-specific morbidity linked to poorer survival.
- Frequent hospital admissions indicate severe clinical morbidity and warrant consideration for heart transplant.
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.
