Isolated Ventricular Septal Defect Closure in Mild Aortic Coarctation: Hemodynamic and Anatomic Evolution of Aortic Isthmus.

Abstract

Optimal management of ventricular septal defect (VSD) with mild aortic coarctation (isthmus velocity ≥1.5 m/s below intervention thresholds) remains contentious because of limited evidence on post-VSD closure aortic remodeling. This retrospective cohort study analyzed 231 children with mild aortic coarctation undergoing isolated VSD closure. Primary interests included survival, aortic coarctation reintervention, longitudinal evolution of isthmic velocity and z scores, and predictors of persistent obstruction (velocity ≥1.5 m/s at 3-year follow-up). With a median of 5.5 (4.3-6.4) years of follow-up, survival was 99.6% (95% CI, 96.9-99.9) at 7 years; only 5 patients (2.2%) required aortic coarctation reintervention within 3.7 years. Isthmic velocity showed a triphasic trajectory: transient postoperative rise, rapid decline through 3 years (71.4% of total reduction), and subsequent stabilization. Anatomically, z scores demonstrated parallel catch-up growth, with the steepest improvement also within the first 3 years. Patients with a concomitant patent ductus arteriosus had lower preoperative velocity and greater early rise, but long-term outcomes matched those of patients without patent ductus arteriosus. By 3-year follow-up, 76.1% of patients achieved normalized velocity (<1.5 m/s). Multivariable analysis identified elevated preoperative aortic valve velocity (odds ratio, 6.82; 95% CI, 1.56-36.28; P = .032) and a smaller preoperative isthmus z score (odds ratio, 0.77; 95% CI, 0.63-0.94; P = .028) as independent predictors of persistent obstruction. Isolated VSD closure achieves coupled hemodynamic and anatomic aortic remodeling in most children with mild aortic coarctation, yielding excellent long-term survival and low reintervention rates. Elevated preoperative aortic valve velocity and a smaller isthmus z score identify high-risk patients who may benefit from intensified surveillance, supporting a physiology-guided, deferred intervention strategy.