Pulmonary valve preservation during tetralogy of Fallot repair: midterm functional outcomes and risk factors for pulmonary regurgitation

Objectives: Many centres have recently adopted pulmonary valve (PV) preservation (PVP) during tetralogy of Fallot (ToF) repair. We sought to identify the midterm functional outcomes and risk factors for pulmonary regurgitation after this procedure. Methods: All patients undergoing PVP during transatrial-transpulmonary repair for ToF with PV stenosis at our institution between January 2007 and December 2020 were reviewed. Results: Overall, 73 patients were included. At the index surgery, the body surface area was 0.31 ± 0.04 m2, the age was 4.9 ± 2.9 months and the preoperative PV z-score was -3.02 ± 1.11. At a mean follow-up of 5.3 ± 2.7 years, the fractional area change of the right ventricle (RV) was 47.1 ± 5.2%, and the tricuspid annular plane systolic excursion z-score was -3.31 ± 1.89%. The 5-year freedom from moderate/severe PV regurgitation was 61.3% [95% confidence interval (CI): 48, 73%]. There was a significant correlation between RV function and moderate/severe PR at follow-up (R2: 0.08; P = 0.03). A comparison with a group of patients undergoing a transannular patch procedure (N = 33) showed superior outcomes for patients with PVP. The preoperative PV z-score and the degree of PR at discharge were risk factors for the early development of moderate/severe PR at follow-up [hazard ratio (HR): 0.64; 95% CI: 0.48, 0.86, P = 0.01 and HR: 2.31; 95% CI: 1.00, 5.36, P = 0.04, respectively]. A preoperative PV annulus z-score ≤ -2.85 was found to be predictive for moderate/severe PR at 5 years after PVP (HR: 2.56; 95% CI: 1.31, 5.01, P = 0.002). Conclusions: A pulmonary valve preservation strategy during tetralogy of Fallot repair should always be attempted. However, a preoperative PV annulus z-score < -2.85 and moderate/severe regurgitation upon discharge are risk factors for midterm pulmonary regurgitation.