Long-Term Fate of the Systemic Right Ventricle: In Patients with Bi-ventricle Versus Single Ventricle

The unique anatomical and physiological characteristics of the systemic right ventricle (sRV) raise prognostic concerns. This study aimed to characterize its long-term clinical course and identify risk factors for adverse outcomes. Patients with sRV who underwent biventricle (BiV) repair or Fontan procedure between January 2000 and July 2023 were reviewed. Comparative analysis between patients with BiV status and single ventricle (SV), and risk factor analysis were performed for long-term outcomes including overall survival and adverse outcomes. In total, 141 patients with sRV (median age 3.1 years (interquartile range (IQR) 2.5-3.8), male 63.1%) were enrolled, with 117 patients (83.0%) undergoing Fontan procedure and 24 patients (17.0%) undergoing BiV repair. Median follow-up duration was 14.3 years (IQR 5.9-18.5). There were no significant differences between BiV and SV in overall survival, composite endpoint for heart failure, percutaneous intervention and major arrhythmia events. BiV showed significantly higher cumulative incidence of re-operation (5-, 10-, 15-year cumulative incidence: 0.340, 0.449, 0.449 vs. 0.136, 0.178, 0.178, p = 0.011) and tricuspid valve surgery (5-, 10-, 15-year cumulative incidence: 0.217, 0.402, 0.402 vs. 0.009, 0.031, 0.031, 0.031, p < 0.001). Multivariable risk factor analysis identified BiV as a significant risk factor for re-operation (subdistribution hazards ratio (sHR) 2.759, 95% confidence interval (CI) 1.028-7.407, p = 0.044) and tricuspid valve surgery (sHR 13.709, 95% CI 1.176-166.667, p = 0.037). sRV, both in SV or BiV circulation, showed good adaptability and tolerable early long-term performance. The follow-up of patients with a sRV requires careful consideration of disease-specific differences and the adoption of individualized surveillance strategies for each condition.