Background: The relationship between fetal aortic valvuloplasty procedural volume and outcomes is crucial to understand whether regionalization should be advised worldwide. This study utilizes the International Fetal Cardiac Intervention Registry to examine the relationship between center volume for fetal aortic valvuloplasty and outcome metrics including procedure success, complications, and fetal death.
Methods: Data were included from institutions performing ≥3 procedures (2001-2018). The primary outcome was technical success, defined as ≥1 balloon inflation across the aortic valve, with increased antegrade flow across the valve and new aortic regurgitation. Secondary end points were procedural complications and fetal periprocedural death (within 48 hours). Univariable and Classification and Regression Tree analyses were performed.
Results: Eleven centers, with volumes ranging from 6 to 31 cases, performed 162 fetal aortic valvuloplasties with a technical success rate of 80.2%. Higher volume was not associated with better technical success or fewer complications but was associated with fewer periprocedural fetal deaths. Employing Classification and Regression Tree modeling, the largest drivers of improved outcomes for all measures were greater estimated fetal weight and gestational age. A single cardiac puncture was associated with greater technical success and fewer procedural complications after accounting for fetal estimated fetal weight and gestational age.
Conclusions: In this registry cohort, higher-volume centers did not have greater fetal aortic valvuloplasty technical success or fewer complications but did have fewer periprocedural fetal deaths. Fetal gestational age and number of cardiac punctures influenced outcomes, suggesting that unmeasured fetal selection criteria, such as different referral patterns, and technical expertise, indicative of overall center/team experience, may influence fetal survival.
Keywords: aortic valve; child; fetal death; punctures; registries.