Supravalvular pulmonary stenosis: A risk factor for reintervention in Noonan syndrome with pulmonary valve stenosis

Objectives: To assess the short- and long-term outcomes of balloon pulmonary valvuloplasty (BPV) in children with Noonan syndrome (NS).

Background: Pulmonary stenosis (PS) is the most common congenital heart lesion in NS. BPV is the accepted first line treatment in PS. However, BPV in NS patients has been reported to be less effective, without specific factors for the need for reintervention being identified.

Methods: Retrospective case-note review of all patients with NS who underwent BPV between 1985 and 2020. Patients were divided into 2 groups: those with supravalvular pulmonary stenosis (SPS) in addition to valvar PS, and those with isolated valvar PS.

Results: A cohort of 54 patients with NS underwent BPV at a median of 275 (interquartile range [IQR]: 108-575) days of age. SPS was present in 32 (59%) patients whereas 22 had (41) isolated PS. The preprocedural invasive gradient was 47 (IQR: 35-69) mmHg, and 44 (IQR: 35-48) mmHg in those with SPS and those without respectively (p = 0.88). Reintervention was required in 22 patients (41%): 17 (77%) with SPS and 5 (23%) without (p = 0.017). Fourteen patients (11 with SPS) required surgical reintervention and 8 (6 with SPS) required further BPV. There was no significant difference in the age at initial BPV, pre- and postprocedural gradients and interval until reintervention between groups.

Conclusion: This is the largest reported cohort of patients with NS undergoing BPV. Although BPV is often successful, the reintervention rates are high. SPS was a risk factor for reintervention.