Impact of Atrioventricular Valve Intervention at Each Stage of Single Ventricle Palliation

<b>Background:</b> Significant atrioventricular valve dysfunction can be associated with mortality or need for transplant in functionally univentricular heart patients undergoing staged palliation. The purposes of this study are to characterize the impact of concomitant atrioventricular valve intervention on outcomes at each stage of single ventricle palliation and to identify risk factors associated with poor outcomes in these patients. <b>Methods:</b> The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for functionally univentricular heart patients undergoing single ventricle palliation from 2013 through 2022. Separate analyses were performed on cohorts corresponding to each stage of palliation (1: initial palliation; 2: superior cavopulmonary anastomosis; 3: Fontan procedure). Bivariate analysis of demographics, diagnoses, comorbidities, preoperative risk factors, operative characteristics, and outcomes with and without concomitant atrioventricular valve intervention was performed. Multiple logistic regression was used to identify predictors associated with operative mortality or major morbidity. <b>Results:</b> Concomitant atrioventricular valve intervention was associated with an increased risk of operative mortality or major morbidity for each cohort (cohort 1: 62% vs 46%, <i>P</i> < .001; cohort 2: 37% vs 19%, <i>P</i> < .001; cohort 3: 22% vs 14%, <i>P</i> < .001). Black race in cohort 1 (odds ratio [OR] 3.151, 95% CI 1.181-9.649, <i>P</i> = .03) and preterm birth in cohort 2 (OR 1.776, 95% CI 1.049-3.005, <i>P</i> = .032) were notable predictors of worse morbidity or mortality. <b>Conclusions:</b> Concomitant atrioventricular valve intervention is a risk factor for operative mortality or major morbidity at each stage of single ventricle palliation. Several risk factors are associated with these outcomes and may be useful in guiding decision-making.