Adverse Remodeling and Prognostic Significance of the Systemic Right Ventricle Across Congenital Heart Disease Subtypes

INTRODUCTION: Patients with congenitally corrected transposition of the great arteries (ccTGA), atrial-corrected transposition (acTGA), and right-ventricular-dominant univentricular heart (UVH) are predisposed to systemic right ventricular dysfunction (sRVd). However, lesion-specific differences in the incidence and timing of adverse outcomes remain unclear. This study aimed to compare the incidence of sRVd, tricuspid regurgitation (TR), and mortality across sRV lesions, and to identify their predictors. METHODS: Retrospective 207 patients with an sRV diagnosed between 1975 and 2023 were categorized into acTGA (n = 53), UVH post-Fontan (n = 75), and ccTGA (n = 79). Incidence, survival analyses and Cox proportional hazards models were assessed for sRVd, TR and mortality. RESULTS: The overall incidence of sRVd was 33.3% at a median age of 26.9 years. At the latest follow-up, sRVd was predominant in the acTGA group (37.7%), compared with UVH (16%) and ccTGA (16.5%). Remarkably, freedom of sRVd at 20 and 40 years were 65.9%, 13% in acTGA group; 30.5%, 5.8% in the UVH group and 43.5%, 26.6% in the ccTGA group, respectively (p < 0.001). Independent predictors included Ebsteinoid TV, pulmonary atresia, acTGA, and UVH. The 20- and 40-years survival was 62.3%, 14.7% (acTGA), 35.2%, 1.5% (UVH), and 46.8%, 22.7% (ccTGA) (p < 0.001). Mortality was associated with PA and NYHA functional class III-IV. Moderate-to-severe TR occurred in one-third of patients. Notably, TR interventions were predominant in ccTGA (p = 0.009). CONCLUSIONS: SRV lesions exhibit distinct clinical phenotypes: acTGA carries the highest overall prevalence of dysfunction, UVH demonstrates the earliest onset, and ccTGA encounters the highest frequency of TR interventions. Despite these differing deterioration patterns, patients with biventricular configurations confer a survival advantage over single-ventricle physiology. These results underscore the importance of anatomy-specific monitoring and timely functional assessment, while also accounting for differences in age and follow-up duration when evaluating long-term outcomes. Graphical abstract available for this article. CLINICAL TRIAL REGISTRY NUMBER: TCTR20250107006.