Abstract 20437: Predictors of Prosthesis Durability After Mitral Valve Replacement in Children
Introduction: Limits of successful mitral valve replacement (MVR) in children include patient size, left ventricular (LV) geometry, and lack of small prosthetic valves. Due to its non-fixed diameter, the Melody valve is suited to address these concerns.
Methods: A single institution retrospective review of children aged less than 18 years undergoing MVR between 1992 and 2016. Primary outcomes include freedom from structural valve deterioration (SVD) and freedom from re-replacement, which were examined as a function of prosthesis type, patient age, diagnosis of LV hypoplasia, and markers of prosthesis-patient mismatch. A conditional recurrent event Cox proportional hazards regression model assessed association between outcome and predictors.
Results: A total of 154 children underwent 213 MVRs: 134 (62.9%) mechanical, 37 (17.4%) porcine, 12 (5.6%) pericardial, and 30 (14.1%) Melody. Median age in years at initial replacement: 8.6 for pericardial valves, 6.0 for mechanical, 3.0 for porcine, and 0.8 for Melody. There were 93 SVD events and 61 re-replacements. Four year freedom from SVD: 66% for mechanical valves, 75% for Melody, 16% for porcine, and undefined for pericardial. Younger patient age, diagnosis of LV hypoplasia, prosthesis type, smaller prosthesis size, and larger prosthesis size: patient weight ratio were univariately associated with hazard of SVD and re-replacement (p<.05). In multivariable modeling, valve type remained a predictor after adjustment for valve size and diagnosis (p=0.002) and after adjustment for age (p<.001). Melody valves were limited to patients aged less than 3.2 years. Secondary analysis examined this age-restricted cohort. Median times to SVD were 4.03, 0.71, and 0.38 years for mechanical, porcine, and pericardial valves. For Melody valves, the SVD rate did not reach 50%. Median times to re-replacement were 7.68, 4.13, 1.47, and 0.77 years for mechanical, Melody, porcine, and pericardial valves.
Conclusions: Melody and mechanical valves are at lower covariate-adjusted risk of SVD and re-replacement than porcine and pericardial valves, and are thus more durable. Given adjustable Melody valve diameter and lack of small mechanical prostheses, the Melody valve should be considered for MVR in neonates and infants.
- Mitral valve disease
- Surgical treatment
- Congenital heart surgery, pediatric
- Congenital heart disease
- Valvular heart disease
Author Disclosures: P.A. Upchurch: None. S. Emani: None.
- © 2016 by American Heart Association, Inc.