Cardiovascular Magnetic Resonance Predictors of Residual Pulmonary Regurgitation and Biventricular Recovery After Pulsta Valve Implantation.

Abstract

Current recommendations for pulmonary valve replacement are based primarily on cardiovascular magnetic resonance (CMR)-derived right ventricular (RV) volume thresholds established in repaired tetralogy of Fallot. However, patients undergoing self-expanding percutaneous pulmonary valve implantation (PPVI) often have mixed pulmonary regurgitation (PR) and pulmonary stenosis with heterogeneous right ventricular outflow tract (RVOT) anatomy. We investigated CMR predictors of residual PR, residual RV enlargement (RVE), and residual biventricular imbalance (BVI) after Pulsta PPVI. We retrospectively analyzed 98 patients with paired pre- and post-procedural CMR. Residual PR was defined as post-procedural PR fraction (PRF) ≥10%, residual RVE as RV end-diastolic volume index (RVEDVi) ≥130 mL/m², and residual BVI as an RV/LV end-diastolic volume ratio ≥1.5. Multivariable regression and restricted cubic spline analyses identified predictors of post-procedural remodeling. Residual PR occurred in 40.8% of patients, residual RVE in 38.8%, and residual BVI in 40.8%. Pyramidal/convex main pulmonary artery morphology and higher baseline PRF independently predicted residual PR, whereas reverse pyramidal/concave morphology was associated with lower residual RVE risk. Higher pre-procedural RV/LV ratio independently predicted residual BVI. RVEDVi z-score remained independently associated with RVEDVi reduction after adjustment for baseline RVEDVi. Although RV volumes decreased substantially after PPVI, LV remodeling varied considerably, and both RVEDVi and LVEDVi change independently contributed to recovery of ventricular balance. After Pulsta PPVI, anatomical factors influence residual PR and RV remodeling. RVEDVi z-score and RV/LV ratio provide complementary information that may improve patient selection.