Diuretic use in the adult Fontan

Objectives: To explore diuretic use in Fontan patients and its association with clinical features and adverse outcomes. Background: In Fontan circulatory failure, ventricular dysfunction, chronically elevated systemic venous pressures, lymphatic abnormalities, and preload deprivation lead to volume expansion, prompting initiation of diuretics, yet use of diuretics has not been widely studied in the adult Fontan patient. Methods: Single center retrospective review of Fontan patients ≥18 years between 2005 and 2018. Descriptive statistics compared Fontan patients by diuretic. Univariate logistic regression analyses were performed. Variables with a p value < 0.05 were selected to create multivariable model using backwards stepwise regression. Kaplan-Meier product-limit estimates stratified by diuretic use were used to find estimates of transplant and death rates. Log-rank tests were used to compare the time to outcome by diuretic use and Cox Proportional Hazards models examined the risk of transplant or death based on diuretic use. Results: Of 206 Fontan patients, 96 (47%) were taking diuretics. Multivariable analysis demonstrated the following associated with diuretic use: age (Adjusted Odds Ratio [AOR] 1.06; p = 0.02); cyanosis (AOR 3.59; p=<0.01); tachyarrhythmia (AOR 2.64; p=<0.01); pacemaker (AOR 2.48; p = 0.02); ≥ moderate atrioventricular (AV) valve regurgitation (AOR 2.88; p=<0.05); New York Heart Association Class II-IV (AOR 3.41; p < 0.01). Diuretic use was associated with a 17-fold increased risk of transplant or death (95% CI 2.3-131.9; p=<0.01). Conclusion: Diuretic use is common in adult Fontan patients. Multiple clinical correlates of heart failure were associated with diuretic use. Transplant-free survival was significantly reduced in those taking diuretics.