Long-term Outcomes of Adults With Single Ventricle Physiology Not Undergoing Fontan Repair: A Multicentre Experience

Abstract

Background: To describe long-term survival and cardiovascular events in adult patients with single ventricle physiology (SVP) without Fontan palliation, focusing on predictors of mortality and comparing groups according to their cardiovascular physiology.

Methods: Multicentre observational and retrospective study including adult patients with SVP without Fontan palliation since their first adult clinic visit. The cohort was subdivided into 3 groups: Eisenmenger, restricted pulmonary flow, and aortopulmonary shunt. Death was considered as the main end point. Other clinical outcomes occurring during follow-up were considered as secondary end points.

Results: A total of 146 patients, mean age 32.5 ± 11.1 years, were analysed. Over a mean follow-up of 7.3 ± 4.1 years, 33 patients (22.6%) died. Survival was 86% and 74% at 5 and 10 years, respectively. Right ventricular morphology was not associated with higher mortality. Four variables at baseline were related to a higher mortality: at least moderate atrioventricular valve regurgitation, platelet count < 150 × 10³/mm³, GFR < 60 mL/min/1.73 m², and QRS > 120 ms). A total of 34.2% of patients were admitted to the hospital due to heart failure, and 7.5% received a heart transplant. Other cardiovascular outcomes were also frequent: atrial arrhythmias in 19.2%, stroke in 15.1%, and pacemaker/implantable cardioverter-defibrillator in 6.2%/2.7%.

Conclusions: Adult patients with SVP who had not undergone Fontan exhibit a high mortality rate and frequent major cardiovascular events. At least moderate atrioventricular valve regurgitation, thrombocytopenia, renal dysfunction, and QRS duration > 120 ms at baseline visit allow identification of a cohort of patients at higher risk of mortality.