title: Hypertrophic Cardiomyopathy in Children, Adolescents, and Young Adults Associated With Low Cardiovascular Mortality With Contemporary Management Strategies.
abstract: BACKGROUND
  Youthful age has been considered the time of greatest risk for patients with hypertrophic cardiomyopathy (HCM), largely because of the possibility of sudden death. The last 2 decades have witnessed more reliable identification of at-risk patients and utilization of implantable cardioverter-defibrillators for prevention of sudden death, and other contemporary treatment options. Whether such management advances have significantly altered the considerable mortality rate for young HCM patients remains unresolved.
  
  
  RESULTS
  We studied long-term outcome in 474 consecutive HCM patients between 7 and 29 years of age presenting at 2 referral institutions. Over 7.1±5.1 years of follow-up (6.0 [3.0, 10.0]), 452 patients (95%) survived, with 95% experiencing no or mild symptoms. HCM-related death occurred in 18 patients (3%; 0.54%/y): arrhythmic sudden death (n=12), progressive heart failure and heart transplant complications (n=5), or postoperatively (n=1). In contrast, aborted life-threatening events occurred in 63 other high-risk patients (13%) with implantable cardioverter-defibrillator interventions for ventricular tachyarrhythmias (n=31), resuscitated out-of-hospital cardiac arrest (n=20), or heart transplant for advanced heart failure (n=12), 1.8%/y, 3-fold higher than HCM mortality. Five- and 10-year survival (considering only HCM deaths) was high (97% and 94%, respectively), virtually identical to that reported in middle-aged adult HCM patients (98% and 94%, P=0.23).
  
  
  CONCLUSIONS
  In a large hospital-based cohort of young HCM patients, representing an age group considered at greatest risk, low mortality rates can be achieved with the application of contemporary cardiovascular treatment strategies, largely because of reliable identification of high-risk patients who benefited from implantable cardioverter-defibrillators for sudden death prevention, thereby creating the opportunity for extended longevity and good quality of life.
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.). hcm.maron@mhif.org.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Maron
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: Ethan J
authors.initials: EJ
authors.lastname: Rowin
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: Susan A
authors.initials: SA
authors.lastname: Casey
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: John R
authors.initials: JR
authors.lastname: Lesser
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: Ross F
authors.initials: RF
authors.lastname: Garberich
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: Deepa M
authors.initials: DM
authors.lastname: McGriff
authors.affiliation: From Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, MN (B.J.M., S.A.C., J.R.L., R.F.G., D.M.M.); and Hypertrophic Cardiomyopathy Center, Tufts Medical Center, Boston MA (E.J.R., M.S.M.).
authors.forename: Martin S
authors.initials: MS
authors.lastname: Maron
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D002648:Child; D015331:Cohort Studies; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009026:Mortality / Q000639:trends; D055815:Young Adult
keywords: cardiomyopathy, hypertrophic; death, sudden; defibrillators, implantable; heart failure; heart transplantation