Predictors of Success Following Valve-Sparing Repair of Tetralogy of Fallot

<b>Objective:</b> We aim to report predictors of success following valve-sparing repair (VSR) for Tetralogy of Fallot (TOF). <b>Methods:</b> We performed a single-institution retrospective review of 70 patients who underwent VSR for TOF from 2007 to 2021. Risk factors for moderate to severe pulmonary insufficiency (PI) and surgical or catheter intervention for right ventricular outflow tract (RVOT) obstruction were analyzed. <b>Results:</b> During a median follow-up time of 6 years (range 1 month to 17 years), 5/70 (7%) patients required surgical or catheter intervention for isolated RVOT obstruction, 8/70 (11%) had moderate or severe PI, and 3/70 (4%) had a combined outcome of RVOT obstruction and PI. Patients who required reintervention had smaller pulmonary valve (PV) z-score (-2.8 vs -1.7, <i>P </i>< .01), were more likely to have isolated infundibular patching (75% vs 31%, <i>P</i> = .02), and had smaller PV z-score at the end of the procedure (-1.4 vs -1.0, <i>P</i> = .03). Patients with significant PI were more likely to have intraoperative valvotomy via Hegar dilation (36% vs 13%, <i>P</i> = .04). The strongest independent predictors of RVOT obstruction and/or PI were preoperative cyanotic episodes (odds ratio 6.0, 95%CI: 1.6-22, <i>P</i> = .01) and valvotomy via Hegar dilation (odds ratio 4.6, 95%CI: 1.0-21, <i>P</i> = .04). <b>Conclusions:</b> Valve-sparing repair of TOF is less likely to be successful if reliant on isolated infundibular patching or not achieving at least a z-score of -1 at the PV at the completion of the procedure. Repairs using blind dilation destabilize the valve and lead to long-term valve incompetence.