Discrete Subvalvular Aortic Stenosis: Severity of Aortic Regurgitation and Rate of Recurrence at Midterm Follow-Up after Surgery

Discrete subaortic stenosis (DSS) is a progressive condition. Controversy still rumbles on as to whether the subaortic membrane causes aortic regurgitation (AR) and whether membrane resection reduces AR severity. We investigated the association between the left ventricular outflow tract peak gradient (LVOT-PG) and AR severity preoperatively and changes in AR severity and obstruction recurrence after surgery in DSS patients. Twenty patients were evaluated before and after surgery for DSS (mean follow-up time: 13.60±9.61 months). The patients were evaluated via transthoracic echocardiography and transesophageal echocardiography, if necessary. The cut-off point for surgery was LVOT-PG ≥50 mmHg or the presence of progressive AR. The mean age of the patients was 28.55±15.23 years, and 35% of them were male. LVOT-PG decreased from a mean of 80.83±42.72 mmHg preoperatively to 19.14±14.03 mmHg postoperatively and to 25.47±16.10 at follow-up. AR was identified in 15 (75%) patients preoperatively: mild in 8 (40%) and moderate in 7 (35%). The postoperative change in AR severity was insignificant. The correlation between preoperative LVOT-PG and the incidence and severity of preoperative AR was not significant. AR severity had no correlation with age. Membrane recurrence occurred in 25% of the patients. Our results indicated no relationship between AR severity and LVOT-PG and the patient’s age. Patient selection for surgery can, therefore, be carried out on the basis of LVOT-PG or AR severity separately. Subaortic resection may reduce AR severity in some patients, but this reduction is not significant. Future studies are required to elucidate whether or not the presence of the AR is an indication for surgery.