Abstract 1924: Longterm Outcome Of Pediatric Patients With Discrete Subaortic Stenosis
INTRODUCTION: We previously reported the clinical outcomes of a large pediatric cohort with discrete subaortic stenosis (SubAS) 1. While patients with more significant left ventricular outflow tract obstruction (LVOTO) at diagnosis progressed rapidly others with mild LVOTO at presentation showed little progression of obstruction or aortic insufficiency (AI). A limitation of our previous study was a relatively short follow-up period.
OBJECTIVE: To extend the follow-up of our previously described cohort with SubAS.
METHODS: Information was gathered retrospectively on 71 previously identified patients diagnosed with SubAS from 1985–1998.
RESULTS: Current data was available on 61/71 patients. At diagnosis the average age was 5.2±0.5 years (mean±SEM), peak LVOT Doppler gradient (Echograd) was 30±3 mmHg, and AI (all mild) was present in 25%. At last assessment the average age was 15.7±0.4 years. Twenty patients were followed only medically and were last reassessed 9.2±1.0 years after diagnosis at 15.8±0.7 years of age. The mean Echograd was unchanged from diagnosis (19±2 vs. 19±3 mmHg). The incidence of AI on echocardiography (all mild) increased from 5% to 55% although none was detectable by auscultation. Forty-one patients underwent surgery 3.0±0.5 years after diagnosis at 7.4±0.6 years of age. The Echograd at diagnosis was 35±3 and increased to 61±6 mmHg pre-operatively. Ten patients were re-operated 5.7±0.7 years after the first surgery and 2 patients had a second re-operation. The last follow up of the operated patients occurred at 15.7±0.6 years of age. At that time the Echograd was 16±3 mmHg and the incidence of AI by echocardiography had increased to 98% (36 mild & 3 moderate) but was evident on auscultation in only 25%.
CONCLUSIONS: This study represents the largest and longest contemporary follow-up of pediatric patients with discrete SubAS. Our results indicate that some patients with SubAS show significant LVOTO at diagnosis and subsequent progression. Surgery in these patients provides good relief of LVOTO but does not eliminate AI. The one third of patients presenting with mild LVOTO and AI show little progression through childhood and adolescence. We suggest that the latter can be safely followed medically. 1) Rohlicek et al. Heart 82:708;1999