Balloon valvuloplasty is the primary treatment for congenital aortic valve stenosis in our centre. We sought to determine independent predictors of reintervention (surgical repair or repeated balloon dilation) after primary valvuloplasty.

We retrospectively studied patients with congenital aortic valve stenosis who underwent balloon valvuloplasty during 2004–2018. The following risk factors were analysed: aortic valve insufficiency after balloon valvuloplasty >+1/4, post-procedural gradient across the aortic valve ≥35 mmHg, pre-interventional gradient across the valve, annulus size, use of rapid pacing, and balloon/annulus ratio. Primary outcome was aortic valve reintervention.

In total, 99 patients (median age 4 years, range 1 day to 26 years) underwent balloon valvuloplasty for congenital aortic valve stenosis. After a mean follow-up of 4.0 years, 30% had reintervention. Adjusted risks for reintervention were significantly increased in patients with post-procedural aortic insufficiency grade >+1/4 and/or residual gradient ≥35 mmHg (HR 2.55, 95% CI 1.13–5.75, p = 0.024). Pre-interventional gradient, annulus size, rapid pacing, and balloon/annulus ratio were not associated with outcome.

Post-procedural aortic valve insufficiency grade >+1/4 and/or residual gradient ≥35 mmHg in patients undergoing balloon valvuloplasty for congenital aortic valve stenosis confers an increased risk for reintervention in mid-term follow-up.