Patients with Fontan circulation beyond the fourth decade of life
Authors: Gribaudo E , Constantine A , Costola G , Kempny A , Gatzoulis M , Rafiq I , Dimopoulos K 
Published: November 2020

Abstract

Background
The survival rate after Fontan procedure is improving and many of these patients now survive well into adulthood. Data on the late morbidity and mortality of Fontan patients in their fourth decade of life are lacking.

Purpose
To evaluate the late outcome of adult patients with Fontan circulation who have survived beyond 35 years.

Methods
Data were collected retrospectively on consecutive patients with a Fontan circulation ≥35 years between 2005 and 2019. Baseline (at 35th birthday) and follow-up data includes functional class, blood tests, history of arrhythmia, heart failure (HF), thromboembolism, Fontan related liver disease (FLD), protein losing enteropathy (PLE) and plastic bronchitis. Echocardiographic data on systemic atrioventricular valve (SAVV) regurgitation and ventricular function were also analysed.

Results
61 patients were included (29, 47.5% female). Tricuspid atresia was the most common underline anatomy (29,47.5%) and the median age at Fontan procedure was 12 [8.0–19.0] years. 34 (56%) patients had an atrio-pulmonary connection Fontan and 15 (24.5%) total cavo-pulmonary connection (86.7% lateral tunnel and 13.3% extra-cardiac conduit), 10 (16%) a Bjork Fontan and 2 (3%) a Kawashima procedure. At baseline 40 (66%) patients were in NYHA class II or III, 7 (11%) had a moderate or severely impaired ventricular function and 12 (20%) had at least moderate SSAV regurgitation. At baseline, 35 (57.4%) patients had experienced at least one arrhythmia, 7 (11.4%) patients had a history of atrial thrombosis or thromboembolic events and 2 (3.3%) of PLE. At a median follow-up of 6.4 [2.9–11.3] years, 11 (18%) patients died, 7 of chronic HF, 1 hepatic carcinoma, 1 sepsis, 1 pulmonary embolism, 1 malignancy (1 cause unknown). During follow-up, 28 (46%) patients had a new episode of atrial arrhythmia, 23 (38%) developed FLD and 2 (3.3%) PLE. 9 (15%) required at least one admission for HF. 2 (3.3%) patients experienced worsening of their ventricular function and 7 (11.4%) of their SAVV regurgitation. On univariable analysis, a baseline diagnosis of PLE (HR 15.23, 95% CI:2.77–83.86, p=0.002), HF (HR 6.18, 95% CI:1.74–21.99, p=0.005), atrial arrhythmia (HR 4.99, 95% CI:1.07–23.21, p=0.04), lower serum albumin (HR 1.14, 95% CI:1.06–1.23, p=0.0006), lower iron levels (HR 1.31, 95% CI:1.02–1.68, p=0.04) and a higher urea (HR 1.18, 95% CI:1.04–1.34, p=0.01) were associated with death or heart transplantation. On bivariable analysis, lower serum albumin was stronger than all other univariable predictors.

Conclusions
Adult Fontan survivors are a high risk population with significant morbidity and mortality driven primarily by HF and other long-term complications of the Fontan operation. The predictors of outcome in this cohort reflects the chronic low cardiac output state and systemic venous hypertension. Vigilance is required to identify patients who may benefit of haemodynamic optimization and close monitoring for Fontan-related complications.

Funding Acknowledgement
Type of funding source: None