Residual pulmonary stenosis and right ventricular contractility in repaired tetralogy of Fallot

Objectives: The impact of residual pulmonary stenosis (rPS) or right ventricular (RV) outflow tract obstruction on prognosis after surgical pulmonary valve insertion) in repaired tetralogy of Fallot patients with pulmonary regurgitation (PR) remains controversial. rPS assessment is partially dependent on RV contractility. We investigated the impact of rPS according to RV ejection fraction (RVEF). Methods: In this multicentre, retrospective study, 117 repaired tetralogy of Fallot patients who underwent surgical pulmonary valve insertion for more than moderate PR between 2003 and 2021 were examined. Regarding rPS, the threshold for PR with rPS (PSR) and PR was 25 mmHg. For RVEF, the threshold for preserved RVEF (pEF) and reduced RVEF (rEF) was 40%. The patients were divided into 4 groups: patients with PR and pEF (PR-pEF) (n = 48), those with PR and rEF (PR-rEF) (n = 44), those with PSR and pEF (PSR-pEF) (n = 16), and those with PSR and rEF (PSR-rEF) (n = 9). Clinical parameters, postoperative adverse event rates and their associations were studied. Results: The 5-year freedom from adverse cardiovascular events was the highest in the PSR-pEF and the lowest in the PSR-rEF groups. The PSR-rEF group had the highest RV end-diastolic pressure (RVEDP) (12 +/- 2.2 mmHg) (P = 0.006). From multivariable analysis, RVEDP was associated with postoperative adverse events (P = 0.016). RVEDP > 8 mmHg was associated with a lower freedom from adverse events. Conclusions: The freedom from adverse events was the lowest in the PSR-rEF group, with the highest RVEDP, suggesting RV systolic and diastolic dysfunction. Reduced RVEF may mask the intrinsic degree of residual stenosis, delay surgical pulmonary valve insertion timing and increase adverse event.