Outcomes in neonatal critical and non-critical aortic stenosis: a retrospective cohort study.

Objective: To compare long-term survival, reinterventions and risk factors using strict definitions of neonatal critical and non-critical valvular aortic stenosis (VAS).

Design: A nationwide retrospective study using data from patient files, echocardiograms and the Swedish National Population Registry.

Setting And Patients: All neonates in Sweden treated for isolated VAS 1994-2018. We applied the following criteria for critical aortic stenosis: valvular stenosis with duct-dependent systemic circulation or depressed left ventricular function (fractional shortening ≤27%). Indication for treatment of non-critical VAS was Doppler mean gradient >50 mm Hg.

Main Outcome Measures: Short-term and long-term survival, aortic valve reinterventions need of valve replacements, risk factors for reintervention and event-free survival.

Results: We identified 65 patients with critical VAS and 42 with non-critical VAS. The majority of the neonates were managed by surgical valvotomy. Median follow-up time was 13.5 years, with no patients lost to follow-up. There was no 30-day mortality. Long-term transplant-free survival was 91% in the critical stenosis group and 98% in the non-critical stenosis group (p=0.134). Event-free survival was 40% versus 67% (p=0.002) in the respective groups. Median time from the initial treatment to reintervention was 3.6 months versus 3.9 years, respectively (p=0.008).

Conclusions: Critical VAS patients had significantly higher need for reintervention during the first year of life, lower event-free survival and lower freedom from aortic valve replacement at age ≥18 years, compared with neonates with non-critical stenosis.