Performance and failure of surgically implanted right ventricle to pulmonary artery (RV-PA) conduit in congenital heart disease

Introduction: Surgical implantation of right ventricle to pulmonary artery (RV-PA) conduit is an important component of congenital heart disease (CHD) surgery but with limited durability and need for re-intervention. Current single center, retrospective, cohort study is reporting longterm performance of surgically implanted RV-PA conduit in a consecutive series of children and adults with CHD. Methods: Patients with CHD referred for RV-PA conduit surgical implantation (October 1997 and January 2022) have been included. Primary outcome was conduit failure defined as peak gradient above 64mmHg/severe regurgitation/ need for conduit-related interventions. Secondary outcome was longitudinal change (increase) of continuous wave Doppler-derived peak gradient across conduit in postoperative echocardiographic studies. Longitudinal echocardiographic studies were available for mixed-effect linear regression analysis. Results: Two-hundred and fifty-two patients were initially included. One-hundred and fifty-one patients were available and elegible for follow-up data collection. After a median follow-up time of 49 months the primary study endpoint occurred in 44 (29%) patients. Multivariable Cox regression model identified adult age (>18 years) at implantation and pulmonary homograft as protective factors (HR 0.11, 95% CI 0.02-0.47, p-value 0.003 and HR 0.34, 95% CI 0.16-0.74, p-value 0.006, respectively). Fever within 7 days of surgical conduit implantation was a strong, independent risk factor for early (within 24 months) failure (HR 4.29, 95% CI 1.41-13.01, p-value 0.01). Longterm use of oral anticoagulant was independently associated with slower progression of peak echocardiographic gradient across conduits (p-value 0.027). Conclusions: In patients with CHD, surgically implanted RV-PA conduit failure is faster in children and after non-homograft conduit implantation. Early fever after surgery is a strong risk factor for early failure. Longterm anticoagulation seems to exert a protective effect.