The following is a summary of “Right Heart Remodeling After Pulmonary Valve Replacement in Patients With Pulmonary Atresia or Critical Stenosis With Intact Ventricular Septum,” published in the November 2023 issue of Cardiology by Irwin et al.

In this study, the researchers focused on evaluating the changes in the right ventricle (RV) following pulmonary valve replacement (PVR) in patients diagnosed with pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (PA/IVS), comparing these changes with those observed in patients with tetralogy of Fallot (TOF). While the remodeling of the RV post-PVR is well-documented in TOF, its characterization in PA/IVS patients remains underexplored. Their investigation utilized cardiac magnetic resonance imaging to analyze the RV changes in these patient groups.

The study involved a retrospective cohort, including PA/IVS patients who underwent PVR at Boston Children’s Hospital between 1995 and 2021. This cohort was matched with TOF patients by age at PVR in a 1:3 ratio. The primary outcome was assessed through median regression modeling, focusing on the post-PVR indexed RV end-diastolic volume. The analysis comprised 20 PA/IVS patients (cases) matched with 60 TOF patients (controls), with a median age at PVR of 14 years.

Interestingly, pre-PVR-indexed RV end-diastolic volume was similar across both groups, although cases displayed higher RV ejection fraction before the procedure (51.4% versus 48.6%; P=0.03). Furthermore, pre-PVR RV free wall and left ventricular (LV) longitudinal strain were alike, while LV midcavity circumferential strain was notably reduced in cases (−15.6 versus −17.1; P=0.001). Following a median post-PVR period of 2 years, both groups exhibited comparable reductions in indexed RV end-diastolic volume. However, cases continued to exhibit higher RV ejection fraction (52.3% versus 46.9%; P=0.007) and less reduction in RV mass (Δ4.5 versus 9.6 g/m²; P=0.004) compared to the TOF group. Despite no significant changes in post-PVR RV and LV longitudinal strain values, LV circumferential strain remained lower in cases. The findings suggest that PA/IVS patients demonstrate similar RV remodeling patterns after PVR, highlighting specific differences such as reduced RV mass reduction and relatively higher RV ejection fraction in comparison to TOF patients. Further exploration focusing on diastolic parameters is warranted to fully understand these distinctive outcomes.

Source: ahajournals.org/doi/10.1161/JAHA.123.031090