Gender differences in clinical outcome and primary prevention defibrillator benefit in patients with severe left ventricular dysfunction: a systematic review and meta-analysis

Heart Rhythm. 2010 Jul;7(7):876-82. doi: 10.1016/j.hrthm.2010.03.042. Epub 2010 Apr 7.


Background: Women are underrepresented in primary prevention implantable cardioverter-defibrillator (ICD) trials, and data on the benefit of ICD therapy in this subgroup are controversial.

Objective: The purpose of this study was to better evaluate the benefit of prophylactic ICD in women by performing a meta-analysis of primary prevention ICD trials that assessed gender differences on the end-points of total mortality, appropriate ICD intervention, and survival benefit of ICD compared with placebo.

Methods: PubMed, CENTRAL, and other databases were searched in October 2009. Studies were included only if they examined gender differences in the specified end-points, providing the hazard ratio (HR) obtained in multiple Cox regression analyses, and adjusted for all confounding variables.

Results: We retrieved five studies (MADIT-II, MUSTT, SCD-HeFT, DEFINITE, COMPANION) that enrolled 7,229 patients (22% women) with dilated cardiomyopathy (74% ischemic). Compared to men, women had no significant difference in overall mortality (HR 0.96, 95% confidence interval [CI] 0.67-1.39, P = .84) but experienced significantly less appropriate ICD interventions (HR 0.63, 95% CI 0.49-0.82, P < or =.001). The benefit of ICD on mortality was significantly higher in men (HR 0.67, 95% CI 0.58-0.78, P <.001) but did not reach statistical significance in women (HR 0.78, 95% CI 0.57-1.05, P = .1).

Conclusion: Women enrolled in primary prevention ICD trials have the same mortality compared to men while experiencing significantly less appropriate ICD interventions, thus suggesting a smaller impact of sudden cardiac death on overall mortality in women with dilated cardiomyopathy. These findings may explain the smaller ICD survival benefit among women.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Aged
  • Arrhythmias, Cardiac / mortality
  • Cardiomyopathy, Dilated / epidemiology
  • Cardiomyopathy, Dilated / mortality
  • Cardiomyopathy, Dilated / therapy*
  • Death, Sudden, Cardiac / epidemiology
  • Defibrillators, Implantable*
  • Female
  • Heart Failure / epidemiology
  • Heart Failure / physiopathology
  • Heart Failure / therapy*
  • Humans
  • Male
  • Middle Aged
  • Primary Prevention
  • Sex Factors
  • Treatment Outcome
  • Ventricular Dysfunction, Left / epidemiology
  • Ventricular Dysfunction, Left / therapy*