Left Ventricular Rehabilitation after Ross operation for Critical Aortic Stenosis with Endocardial Fibroelastosis

OBJECTIVE: Congenital critical aortic stenosis (AS) is frequently accompanied by endocardial fibroelastosis (EFE), impairing diastolic compliance and long-term ventricular performance. An early Ross procedure, with or without concomitant EFE resection, may restore left ventricular (LV) function; however, long-term functional outcomes remain poorly characterized. We evaluated long-term clinical and functional outcomes following neonatal and infant Ross, in patients with and without EFE. METHODS: Patients who underwent a Ross operation at <1 year of age between January 2005 and January 2025 were included. Demographic, echocardiographic, and long-term clinical data were analyzed. Subgroup assessment was performed in patients with the most pathologic LV, i.e. with EFE, and included cardiac magnetic resonance imaging (CMR) and cardiopulmonary exercise testing (CPET). The primary outcome was survival; secondary outcomes included LV function, EFE recurrence, and exercise capacity. RESULTS: Thirty-six patients underwent the Ross procedure (median age: 55 days, interquartile range: 20-136) and 17 patients (47%) had EFE. Operative mortality was 5.6% (2/36), with no late deaths during follow-up (10±4 years). Late echocardiography demonstrated unobstructed LV outflow and normalized LV function at follow-up. Ten patients with EFE, who consented to additional diagnostic evaluation, had mostly normalized LV function confirmed on CMR with no evidence of recurrent EFE. In these 10 patients, CPET demonstrated predominantly normal aerobic capacity. CONCLUSIONS: Biventricular repair in neonates and infants with critical AS, is associated with excellent survival and substantial LV recovery even in the presence of severe EFE.