Abstract 19928: Surgical Myectomy for Patients with Noonan Syndrome and Symptomatic Left Ventricular Outflow Tract Obstruction: A Case Control Series
Introduction: Approximately 20-30% of patients (pts) with Noonan syndrome (NS) have asymmetric left ventricular hypertrophy (LVH) and LV outflow tract obstruction (LVOTO). The role of surgical myectomy in patients with NS and symptomatic LVOTO is unknown. The purpose of this study was to compare the clinical features and outcomes of pts with NS and LVOTO with age and gender matched patients with non-syndromic, obstructive hypertrophic cardiomyopathy (HCM) after myectomy.
Methods: Two cohorts were selected and retrospectively analyzed using Mayo Clinic databases from 1996-2014. Subjects included NS pts with LVH and LVOTO. Controls included 25 non-syndromic patients with obstructive HCM, matched to age, gender, and body surface area, who had myectomy during the same timeframe.
Results: 23 patients with NS and LVH were identified, of whom 12 underwent myectomy (8 males) for severe LVOTO [10 pediatric, 2 adult; 13 ± 10 yrs old (range 1 - 39)]. Pre and post-operative clinical and imaging data are shown in the Table. Ten septal and 2 combined septal/apical myectomies were performed in NS pts. Similar clinical and echocardiographic improvements were noted in both groups and most had only mild residual LVOTO (Table). There were no perioperative deaths. The majority showed improvement in NYHA class (7/8 NS versus 18/22 controls, 12 ± 13 months follow up). Decreased left atrial (LA) volume index was noted in HCM controls and was not found in NS pts (p < 0.05). Complications were rare: second myectomy was needed in 2 NS pts versus 1 control pt; heart block occurred in 1 control pt, and arrhythmias in 1 control pt. Only 1 late death in an NS pt occurred.
Conclusion: In NS pts with LVH and symptomatic LVOTO, myectomy reduces both gradient and NYHA class similar to results seen in pts with non-syndromic HCM. Post-operative morbidity was not increased. Residual gradients were slightly higher and greater LA dilation persisted in NS pts, but myectomy should not be avoided simply because of the presence of NS.
Author Disclosures: J.T. Poterucha: None. P.W. O’Leary: None. H.M. Connolly: None. S.R. Ommen: None. M.J. Ackerman: Ownership Interest; Significant; Transgenomic.. Consultant/Advisory Board; Modest; Boston Scientific, Gilead Sciences, Medtronic, and St. Jude Medical.. H.V. Schaff: None. J.A. Dearani: None. F. Cetta: None. B.W. Eidem: None.
- © 2014 by American Heart Association, Inc.