Right Heart Remodeling After Pulmonary Valve Replacement in Patients with Pulmonary Atresia or Critical Stenosis with Intact Ventricular Septum

Abstract

AbstractBackgroundPatients with pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (PA/IVS) and biventricular circulation may require pulmonary valve replacement (PVR). Right ventricular (RV) remodeling after PVR is well-described in tetralogy of Fallot (TOF); we sought to investigate RV changes in PA/IVS using cardiac magnetic resonance imaging (CMR).MethodsA retrospective cohort of PA/IVS patients who underwent PVR at Boston Children’s Hospital from 1995-2021 with CMR before and after PVR was matched 1:3 with TOF patients by age at PVR. Median regression modeling was performed with post-PVR indexed RV end-diastolic volume (RVEDVi) as the primary outcome.Results20 PA/IVS patients (cases) were matched with 60 TOF (controls), with median age at PVR 14 years. Pre-PVR RVEDVi was similar between groups; cases had higher RV ejection fraction (EF; 51.4 vs 48.6%, p=0.03). Pre-PVR RV free wall and LV longitudinal strain (LS) were similar, although LV mid-cavity circumferential strain (CS) was decreased in cases (−15.6 vs -17.1, p=0.001). At median 2 years after PVR, RVEDVi was similarly reduced; cases continued to have higher RV EF (52.3% vs 46.9%, p=0.007) with less reduction in RV mass (Δ4.5 vs 9.6 g/m2, p=0.004). Post PVR, RV and LV LS remained unchanged and LV CS was similar, though lower in cases.ConclusionCompared with TOF patients, PA/IVS patients demonstrate similar RV remodeling after PVR, with lesser reduction in RV mass and comparatively higher RVEF. While no differences were detected in peak systolic RV or LV strain values, further investigation of diastolic parameters is needed.Clinical Perspective-This paper provides new insights on the remodeling of the right heart in patients pulmonary atresia with intact ventricular septum or critical pulmonary stenosis, namely that compared with tetralogy of Fallot patients, these patients demonstrate overall similar right ventricular remodeling following pulmonary valve replacement.-CMR strain imaging found no significant pre-post pulmonary valve replacement differences in right ventricular or left ventricular systolic parameters