Clinical, Echocardiographic, and Surgical Correlates of Ventricular Septal Defect Size in a Pediatric Population from Pakistan: A Retrospective Cohort Study

Abstract

Background: Ventricular septal defect (VSD) is a common congenital cardiac lesion with clinical outcomes influenced by defect anatomy, size, and hemodynamics. Evidence linking VSD characteristics with clinical severity, pulmonary artery pressure, and intervention timing remains limited in Pakistan. This study evaluated these associations among children at a tertiary pediatric cardiology center in Khyber Pakhtunkhwa.

Methodology: This retrospective cohort study included children aged 0–12 years evaluated at Lady Reading Hospital, Peshawar, between March and October 2025. Of 1,291 children undergoing echocardiography, 312 (24.2%) met the eligibility criteria. VSDs were classified by size relative to the aortic annulus as small (≤25%), medium (>25%–75%), or large (>75%). Clinical severity was assessed using the modified Ross classification. Systolic pulmonary artery pressure (SPAP) was estimated echocardiographically, with elevated SPAP defined as >40 mmHg. Clinical, echocardiographic, intervention, and postoperative outcomes were analyzed using univariable and multivariable methods.

Results: Of 312 children, 94 (30.1%) had small, 140 (44.9%) medium, and 78 (25.0%) large VSDs; 69.9% were perimembranous. Modified Ross Class III/IV symptoms increased across size categories (4.3%, 30.0%, and 78.2%, respectively; p < 0.001), as did elevated SPAP (8.5%, 32.1%, and 83.3%; p < 0.001). Mean SPAP increased from 28.5±8.2 mmHg in small to 58.6±14.8 mmHg in large VSDs. VSD size correlated with Ross class (ρ = 0.72), while the VSD/aortic-annulus ratio correlated with SPAP (r = 0.72; both p < 0.001). Surgical closure was performed in 122 (39.1%) children, including 72 (92.3%) with large VSDs. Among children with large VSDs, 42 (53.8%) underwent closure before 6 months. Postoperative 30-day mortality was 0.8%, and permanent pacemaker implantation occurred in 2.5%. Rural residence, low socioeconomic status, and large VSD size were associated with surgical closure after 6 months.

Conclusion: Larger VSDs were associated with greater clinical severity, impaired growth, higher estimated SPAP, and more frequent surgical intervention. These observational findings support locally adapted referral and intervention pathways, although prospective studies with standardized hemodynamic assessment are needed.