title: The gender-paradox among patients with implantable cardioverter-defibrillators: a propensity-matched study.
abstract: BACKGROUND
  Several meta-analyses of the implantable cardioverter-defibrillator (ICD) clinical trials have demonstrated that while men derived a mortality reduction with prophylactic ICD implantation, women did not. These trials also observed that women receive less appropriate ICD shock therapy compared to men. We aimed to investigate this "gender-paradox" among a heterogeneous community cohort of patients receiving ICDs.
  
  
  METHODS
  We identified 1,445 consecutive patients undergoing ICD implantation from 1997 to 2007. The study population consisted of 582 patients, of whom 291 were women who could be propensity matched to 291 men, based on age, ejection fraction, implantation indication (primary or secondary), etiology of cardiomyopathy (ischemic or nonischemic), and the presence of a cardiac resynchronization therapy-defibrillator (CRT-D) device. The impact of gender difference on the probability of death and appropriate ICD shocks for ventricular arrhythmias was calculated using multivariable Cox proportional hazards analyses.
  
  
  RESULTS
  During a mean follow-up of 909 ± 901 days, compared to men, women demonstrated a similar risk of death (25% vs 25%, adjusted hazard ratio [AHR] 1.05 [95% confidence interval (CI) 0.81-1.35], P = 0.74). In contrast, women demonstrated a decreased probability of appropriate ICD-shock therapy (14% vs 19%, AHR 0.80 [95% CI 0.59-0.88], P = 0.03) compared to men, and among cohorts with a nonischemic cardiomyopathy (10% vs 20%, P < 0.001) and CRT-D devices (7% vs 19%, P = 0.01).
  
  
  CONCLUSIONS
  Among a community cohort with ICDs, women have a similar mortality compared to men while experiencing less appropriate ICD therapy. These results support the findings of a lower arrhythmic mortality among women.
authors.affiliation: Division of Cardiology, Section of Heart Rhythm Management, and the Evidence Based Practice Center, Hartford Hospital, Hartford, Connecticut, USA.
authors.forename: Sanjeev P
authors.initials: SP
authors.lastname: Bhavnani
authors.forename: Vamsimohan
authors.initials: V
authors.lastname: Pavuluri
authors.forename: Craig I
authors.initials: CI
authors.lastname: Coleman
authors.forename: Danette
authors.initials: D
authors.lastname: Guertin
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Yarlagadda
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Clyne
authors.forename: Jeffery
authors.initials: J
authors.lastname: Kluger
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004554:Electric Countershock / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D008297:Male; D057216:Propensity Score; D012189:Retrospective Studies; D017678:Sex Distribution; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: gender; implantable cardioverter-defibrillator; mortality; risk stratification; shocks