Comparing outcomes of active closure versus natural evolution in hemodynamically significant restrictive PmVSDs: Insights from the FRANCISCO cohort

Introduction

Hemodynamically significant restrictive perimembranous ventricular septal defects (PmVSDs) present management challenges, requiring a choice between active closure or watchful waiting. This study evaluates the early impact of these strategies on left ventricular (LV) dimensions, growth, functional status, and cardiovascular events.

Method

In the multicenter, prospective nationwide FRANCISCO cohort, 206 patients (aged > 1 year) with hemodynamically significant (LV end-diastolic diameter (LVEDD) z-score ≥ 2), restrictive (without pulmonary arterial hypertension) PmVSDs were assigned to active shunt closure or natural evolution. LVEDD z-scores, body mass index (BMI) z-scores, NYHA/ROSS class, and cardiovascular events were collected over a 9 to 36-month follow-up period.

Results

Overall, 30.1% underwent active PmVSD closure while 69.9% followed natural evolution. Closed defects averaged 7.8 mm, while those evolving naturally averaged 5.1 mm (p < 0.001). Active shunt closure significantly reduced LVEDD z-scores from 3.3 to 1.1 (p < 0.001), and improved BMI z-scores and NYHA/ROSS class (both p < 0.001). In children under 3 years, BMI z-scores improved from −2.0 to −0.3 (p < 0.001) and NYHA/ROSS class from 1.5 to 1.0 (p = 0.002). Natural evolution group saw a significant reduction in LVEDD z-scores from 2.7 to 2.0 (p < 0.001) without significant changes in BMI z-scores (p = 0.384) or NYHA/ROSS class (p = 0.332). Cardiovascular events occurred in 7.3% of patients (4.8% in the active closure group versus 8.3% in the natural evolution group, p = 0.560) (Figure 1).

Conclusion

On early follow-up, active shunt closure significantly improves clinical outcomes, especially in larger defects and younger children, compared to natural evolution, with no significant difference in cardiovascular event incidence between the two strategies.