Abstract 2767: Congenital Heart Disease And Hypertrophic Cardiomyopathy In Noonans Syndrome: Determinants Of Outcome.
To further understand the implications of hypertrophic cardiomyopathy (HCM) in Noonans syndrome (NS), we characterized our cardiovascular experience of NS over 40 years. All 141 children referred to our cardiovascular service since 1966 NS were reviewed. Time-related outcomes were modeled using multiphase parametric techniques and subjected to risk-hazard analysis with bootstrapping. Survival outcomes in NS HCM were then compared with a contemporaneous series of children with non-NS HCM (N=120) from our institution. The incidences of cardiac anomalies were: PV dysplasia, 56%; ASD, 24%; HCM, 23%; VSD, 11%; MV dysplasia, 6%; left SVC, 5%; tetralogy of Fallot and coarctation 3%. HCM in excess of what would be expected based on type and severity of cardiovascular anomaly was diagnosed in 30/141 (23%). In 18 of these (57%), HCM co-existed with an associated anomaly (PV dysplasia=14, VSD=2, ASD=4, MV dysplasia=4 and coarctation=1). In contrast, all 120 non-NS pediatric HCM at our institution had no associated cardiovascular anomaly. Cardiac surgery was necessary in 45 (32%) and was predicted by septal defects, RVOT gradient and LVOT gradient >30mmHg. Surgery was directed to the RVOT or septum in >75% cases. Left myectomy was necessary in only 5 (11%). Overall survival was 92% +/-3 at 10 years and death was independently predicted by HCM and LVOT obstruction. Risk-adjusted late-phase hazard for death was significantly higher for NS HCM than non-NS HCM (p=.008).
Conclusions HCM in NS usually occurs in asociation with other lesions. HCM in NS carries a worse late prognosis than non-NS HCM. Survival outcomes are good, although the presence of HCM is an independent predictor of death.