Long-Term Outcomes of Hypertrophic Cardiomyopathy Diagnosed During Childhood

• DOI: 10.1161/circulationaha.117.028895
• Publication Date: 2018-02-28T10:25:15Z
• Authors: Peta M.A. Alexander; Alan W. Nugent; Piers E.F. Daubeney; Katherine J. Lee; Lynn A. Sleeper; Tibor Schuster; Christian Turner; Andrew M. Davis; Chris Semsarian; Steven D. Colan; Terry Robertson; James Ramsay; Robert Justo; Gary F. Sholler; Ingrid King; Robert G. Weintraub
• Keywords: Male; Health Status; Adrenergic beta-Antagonists; Electric Countershock; 610; 1102 Cardiovascular Medicine And Haematology; 2705 Cardiology and Cardiovascular Medicine; Pediatric and congenital heart disease, including cardiovascular surgery; 03 medical and health sciences; 2737 Physiology (medical); 0302 clinical medicine; National Australian Childhood Cardiomyopathy Study; Humans; Longitudinal Studies; Child; Retrospective Studies; Myocardial cardiomyopathy disease; Age Factors; Australia; Infant, Newborn; Infant; 1103 Clinical Sciences; Pediatric and congenital heart disease; Cardiomyopathy, Hypertrophic; Progression-Free Survival; Defibrillators, Implantable; 3. Good health; Death, Sudden, Cardiac; 1117 Public Health And Health Services; Cardiovascular System & Hematology; Child, Preschool; Disease Progression; Heart Transplantation; Female; including cardiovascular surgery

Background: Late survival and symptomatic status of children with hypertrophic cardiomyopathy have not been well defined. We examined long-term outcomes for pediatric hypertrophic cardiomyopathy.

Methods: The National Australian Childhood Cardiomyopathy Study is a longitudinal population-based cohort study of children (0–10 years of age) diagnosed with cardiomyopathy between 1987 and 1996. The primary study end point was time to death or cardiac transplantation.

Results:

There were 80 patients with hypertrophic cardiomyopathy, with a median age at diagnosis of 0.48 (interquartile range, 0.1, 2.5) years. Freedom from death/transplantation was 86% (95% confidence interval [CI], 77.0–92.0) 1 year after presentation, 80% (95% CI, 69.0–87.0) at 10 years, and 78% (95% CI, 67.0–86.0) at 20 years. From multivariable analyses, risk factors for death/transplantation included symmetrical left ventricular hypertrophy at the time of diagnosis (hazard ratio, 4.20; 95% CI, 1.60–11.05; P =0.004), Noonan syndrome (hazard ratio, 2.88; 95% CI, 1.02–8.08; P =0.045), higher posterior wall thickness z score (hazard ratio, 1.45; 95% CI, 1.22–1.73; P <0.001), and lower fractional shortening z score (hazard ratio, 0.84; 95% CI, 0.74–0.95; P =0.005) during follow-up. Nineteen (23%) subjects underwent left ventricular myectomy. At a median of 15.7 years of follow-up, 27 (42%) of 63 survivors were treated with β-blocker, and 13 (21%) had an implantable cardioverter-defibrillator.

Conclusions: The highest risk of death or transplantation for children with hypertrophic cardiomyopathy is within 1 year after diagnosis, with low attrition rates thereafter. Many subjects receive medical, surgical, or device therapy.