Preoperative thresholds for mid-to-late haemodynamic and clinical outcomes after pulmonary valve replacement in tetralogy of Fallot

Aims The right ventricle (RV) remodels early after pulmonary valve replacement (PVR) in tetralogy of Fallot (TOF) patients. Previously reported preoperative thresholds to achieve early postoperative RV normalization were consistently close to 80 mL/m2 for end-systolic volume (ESV) and 160 mL/m2 for end-diastolic volume (EDV). Our objective was to determine whether these thresholds were also associated with mid-to-late RV normalization and clinical events. Methods and results Out of a multicentre cohort of 157 TOF patients who had undergone PVR, in 65 patients (62% male, age 29 ± 8 years, homograft in 98%) cardiovascular magnetic resonance (CMR) imaging was performed preoperatively and >3 years (6.3 years, interquartile range: 4.9–9.5) postoperatively. Mid-to-late haemodynamic outcome was classified as: ‘RV normalization’ [RV ejection fraction (EF) > 48% and RV EDV 120 mL/m2) in 17 of 65 (26%) patients. Preoperative RV ESV 95 mL/m2 were at increased risk for unfavourable mid-to-late haemodynamic outcome (common OR: 25.5, 95% CI: 5.35–122) and events (hazard ratio: 2.89, 95% CI: 1.03–8.11). Conclusion In TOF patients who had undergone PVR, the best preoperative threshold to achieve mid-to-late RV normalization was RV ESV 95 mL/m2 were at increased risk for suboptimal haemodynamic outcome and adverse clinical events. Our findings may assist in timing of PVR.