Primary prevention implantable cardioverter-defibrillators and survival in older women

Objectives: The purpose of this study was to assess the benefit of primary prevention implantable cardioverter defibrillators (ICDs) in women.

Background: Clinical trials of primary prevention ICDs enrolled a limited number of women.

Methods: Using a propensity score method, we matched 490 women ≥65 years of age who received an ICD during a hospitalization for heart failure in the National Cardiovascular Data Registry ICD Registry from January 1, 2006, through December 31, 2007, to 490 ICD-eligible women without an ICD hospitalized for heart failure in the Get With The Guidelines for Heart Failure database from January 1, 2006, through December 31, 2009. The primary endpoint was all-cause mortality obtained from the Medicare Claims Database. An identical analysis was conducted in men.

Results: Median follow-up for patients with an ICD was 4.6 years versus 3.2 years for patients with no ICD. Compared with women with no ICD, those with an ICD were younger and less frequently white. In the matched cohorts, the survival of women with an ICD was significantly longer than that of women without an ICD (adjusted hazard ratio: 0.79, 95% confidence interval: 0.66 to 0.95; p = 0.013). Similarly, men with an ICD had longer survival than men without an ICD (adjusted hazard ratio: 0.73, 95% confidence interval: 0.65 to 0.83; p < 0.0001). There was no interaction between sex and the presence of an ICD with respect to survival (p = 0.44).

Conclusions: Among older women with left ventricular dysfunction, a primary prevention ICD was associated with a significant survival benefit that was nearly identical to that seen in men. These findings support the use of primary prevention ICDs in eligible patients regardless of sex.