title: Long-term survival in patients with resting obstructive hypertrophic cardiomyopathy comparison of conservative versus invasive treatment.
abstract: OBJECTIVE
  The aim of this study was to compare the survival of patients with hypertrophic cardiomyopathy (HCM) and resting left ventricular outflow tract (LVOT) obstruction managed with an invasive versus a conservative strategy.
  
  
  BACKGROUND
  In patients with resting obstructive HCM, clinical benefit can be achieved after invasive septal reduction therapy. However, it remains controversial whether invasive treatment improves long-term survival.
  
  
  METHODS
  We studied a consecutive cohort of 649 patients with resting obstructive HCM. Total and HCM-related mortality were compared in 246 patients who were conservatively managed with 403 patients who were invasively managed by surgical myectomy, septal ethanol ablation, or dual-chamber pacing.
  
  
  RESULTS
  Multivariable analyses (with invasive therapy treated as a time-dependent covariate) showed that an invasive intervention was a significant determinant of overall mortality (hazard ratio: 0.6, 95% confidence interval: 0.4 to 0.97, p = 0.04). Overall survival rates were greater in the invasive (99.2% 1-year, 95.7% 5-year, and 87.8% 10-year survival) than in the conservative (97.3% 1-year, 91.1% 5-year, and 75.8% 10-year survival, p = 0.008) cohort. However, invasive therapy was not found to be a significant independent predictor of HCM-related mortality (hazard ratio: 0.7, 95% confidence interval: 0.4 to 1.3, p = 0.3). The HCM-related survival was 99.5% (1 year), 96.3% (5 years), and 90.2% (10 years) in the invasive cohort, and 97.8% (1 year), 94.6% (5 years), and 86.9% (10 years) in the conservative cohort (p = 0.3).
  
  
  CONCLUSIONS
  Patients treated invasively have an overall survival advantage compared with conservatively treated patients, with the latter group more likely to die from noncardiac causes. The HCM-related mortality is similar, regardless of a conservative versus invasive strategy.
authors.affiliation: Division of Cardiology, Toronto General Hospital, University Health Network, University of Toronto, Ontario, Canada.
authors.forename: Warren
authors.initials: W
authors.lastname: Ball
authors.forename: Joan
authors.initials: J
authors.lastname: Ivanov
authors.forename: Harry
authors.initials: H
authors.lastname: Rakowski
authors.forename: E Douglas
authors.initials: ED
authors.lastname: Wigle
authors.forename: Meredith
authors.initials: M
authors.lastname: Linghorne
authors.forename: Anthony
authors.initials: A
authors.lastname: Ralph-Edwards
authors.forename: William G
authors.initials: WG
authors.lastname: Williams
authors.forename: Leonard
authors.initials: L
authors.lastname: Schwartz
authors.forename: Ashley
authors.initials: A
authors.lastname: Guttman
authors.forename: Anna
authors.initials: A
authors.lastname: Woo
mesh_terms: D055011:Ablation Techniques / Q000379:methods; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000367:Age Factors; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality* / Q000628:therapy*; D015331:Cohort Studies; D015897:Comorbidity; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012146:Rest; D012720:Severity of Illness Index; D012737:Sex Factors; D014463:Ultrasonography; D014694:Ventricular Outflow Obstruction / Q000401:mortality* / Q000628:therapy*
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D000431:Ethanol