Discrete Left Ventricle Outflow Tract Obstruction in Children: Incidence and Predictors of Recurrence. A Multi-Center Study.

Objectives: The purpose of this study is to measure the incidence of recurrence of discrete subaortic stenosis (DSS) after primary resection in two major cardiac centers in Saudi Arabia and to identify risk factors associated with recurrence. Methods: Data on 234 patients who were diagnosed with DSS and underwent surgical resection between 1999 and 2018 were retrospectively reviewed. Patient demographics as well as echocardiographic, surgical, and pathological data were compared between patients with recurrence and non-recurrence. Results: The overall recurrence incidence after primary resection was 44.87% (N=105). Most patients were male (59%). The median age at the 1st operation was 60 months (range 3 months to 133 months). The presence of aortic stenosis at the time of diagnosis was significantly associated with recurrence (p-value=0.002). The overall median peak gradient in which the primary resection was indicated is 60 mmHg (range 11 to 152 mmHg). The median peak gradient pre-operation and post-operation were significantly higher for the recurrence group (p-value=0.018 and p<0.001, respectively). We used univariate and multivariate analysis and controlled for the follow-up time, but there were no significant independent predictors of recurrence. Conclusion: The recurrence rate of DSS after the primary resection is relatively high in this study. Further prospective studies are needed to draw a definite conclusion on risk factors for recurrence after primary resection.