Long-term follow-up of atrioventricular valve function in Fontan patients: effect of atrioventricular valve surgery.

Abstract

The aim of this study was to evaluate the relationship between atrioventricular valve and ventricular function in Fontan survivors, including the effect of atrioventricular valve surgery. Analysis focused on transplant-free survival and the need for atrioventricular valve surgery in single ventricle patients after Fontan completion. Longitudinal echocardiographic examination of long-term valve and ventricular function was performed. Fontan completion was performed in 113 patients, having a right univentricular morphology in 33.6%, a left ventricle morphology in 62.8% and ambiguous in 3.6%. Perioperative mortality was 2.7% (n = 3). Within a median follow-up of 16.3 years (interquartile range 10.6-23.6), transplant-free survival was 96.1 ± 1.9% and 90.4 ± 5.8% at 10-25 years. Twenty AV valve procedures were performed in 14 (12.4%) children, respectively, pre-Fontan (n = 10), per-Fontan (n = 8) and post-Fontan (n = 2), resulting in a cumulative incidence of AV valve surgery is 5.7 ± 2.2% and 12.3 ± 3.2% at 1-5 years. Atrio-ventricular valve function deteriorated over time [hazard ratio (HR) 1.112, 95% confidence interval (CI) 1.089-1.138, P < 0.001], without difference for valve morphology (P = 0.736) or ventricular dominance (P = 0.484). AV valve dysfunction was greater in patients requiring AV valve surgery (HR 20.383, 95% CI 6.223-36.762, P < 0.001) but showed a comparable evolution since repair to those without valve surgery (HR 1.070, 95% CI 0.987-1.160, P = 0.099). Progressive time-related ventricular dysfunction was observed (HR 1.141, 95% CI 1.097-1.182, P < 0.001), significantly less in left ventricle-dominance (HR 0.927, 95% CI 0.860-0.999, P = 0.047) but more after AV valve surgery (HR 1.103, 95% CI 1.014-1.167, P = 0.022). In a homogeneously treated Fontan population, 25-year transplant-free survival is encouraging. Atrio-ventricular valve surgery was necessary in 12.4%, resulting mostly in a durable valve function. However, a slow time-related decline of atrioventricular valve function as of ventricular function is worrisome, evoking a role for additional heart failure therapy.