Long-Term Aortic Valve Function in Patients With or Without Surgical Treatment for Discrete Subaortic Stenosis

The purpose of this study was to evaluate the long-term function of the aortic valve in patients with discrete subaortic stenosis (DSS), and its prognostic implications. 34 patients with the diagnosis of isolated DSS were treated at our pediatric heart center between 1992 and 2019. Demographic, echocardiographic and surgical data were analyzed. 26 patients had surgery to remove the subaortic membrane. The primary endpoint of this study was a change in the aortic valve function, secondary outcomes included functional class, aortic valve replacement, and reoperation due to recurrence of DSS. The mean post-operative follow-up time was 7.07 years (1-22.5). At the time of the most recent follow up, in the surgical group 11 patients (46%) had echocardiographic evidence of deterioration in their aortic valve insufficiency (AI) (p < 0.002). The deterioration was associated with a pre-operative left ventricular outflow tract (LVOT) gradient greater than 49 mmHg (p < 0.022). 8 patients with DSS were followed for a mean of 12.9 years (6.8-21.3), without meeting the criteria for surgical intervention, none showed any change in the aortic valve function during follow-up time. DSS resection may not prevent worsening of aortic valve insufficiency over time. Patients with stable AI and low LVOT gradient may not require surgery. Given these findings, it may be appropriate to carefully follow patients with new onset AI and low LVOT gradient, delaying surgical intervention.