OBJECTIVE:Transcatheter valve perforation for pulmonary atresia intact ventricular septum is the standard of care for patients with mild right ventricular hypoplasia. However, its role in moderate right ventricular hypoplasia has been less well defined. We sought to report the long-term outcome of patients with moderate hypoplastic right ventricle who had undergone the procedure. DESIGN, SETTINGS, AND PATIENTS:We performed a retrospective analysis on patients who had undergone transcatheter pulmonary valve perforation from January 1996 to January 2015 at our institution. The procedures would be carried out irrespective of the right ventricular size, as long as there were no absolute contraindications. INTERVENTION AND OUTCOME MEASURES:Demographic and procedural data were correlated with outcome measures. Outcomes analyzed included procedural success, reintervention rates, final circulation type, and functional class. Multivariate analysis and receiver operator curve were used to identify for parameters in predicting biventricular circulation. RESULTS:The procedural success rate was 92% (33 out of 36) in this group with moderate right ventricular hypoplasia (tricuspid valve z score -4.2 ± 3.0, 69.4% of patients with z score <-2.5). Early reintervention rate was 39%, mostly being insertion of modified Blalock-Taussig shunt. Overall reintervention-free survival was 53%, 30%, and 19% at 1, 6, and 12 months postintervention. Despite no significant catch-up right ventricular growth, majority of survivors (84%) enjoyed a biventricular circulation with good functional status. A tricuspid to mitral valve ratio >0.79 was a good predictor of biventricular outcome. (specificity of 100%, positive predictive value 100%) CONCLUSION: Encouraging long-term results with biventricular circulation and functional status were demonstrated with transcatheter pulmonary valve perforation in patients even with moderate hypoplastic right ventricle, which is comparable to that with mild right ventricular hypertrophy. The baseline tricuspid to mitral valve ratio was identified as a potentially useful tool in predicting biventricular circulation.