Comparison of Mortality in Women Versus Men With Infections Involving Cardiovascular Implantable Electronic Device

Device infection is a complication of implantable cardioverter-defibrillator (ICD) therapy that significantly increases mortality. Risk factors associated with death and ICD infection are poorly understood. The purpose of this study was to identify patient characteristics associated with death after cardiovascular implantable electronic device (CIED) infection. This is a retrospective cohort study of 64,903 Medicare fee-for-service patients who received an ICD in 2007, including 1,855 with device infection. Long-term survival was significantly reduced with CIED infection (71.6% vs 85.0%, p <0.001). Regression analysis accounting for age, race, gender, and 28 co-morbidities identified only 2 patient characteristics associated with decreased long-term survival with CIED infection: female gender and human immunodeficiency virus/acquired immunodeficiency syndrome. In patients with CIED infection, women had substantially reduced long-term survival compared with men (67.3% vs 72.9%, p <0.02). The risk-adjusted hazard ratio for long-term mortality with device infection in women compared with that in men increased significantly from 0.86 (95% confidence interval [CI] 0.82 to 0.91) to 1.25 (95% CI 1.02 to 1.53), corresponding to a risk increase of >45%. Importantly, a substantial portion of this excess mortality occurred after the index admission for infection, when the hazard ratio for death in women compared with that in men increased from 0.86 (95% CI 0.82 to 0.91) to 1.20 (95% CI 0.96 to 1.51) with CIED infection, despite little gender difference in admission length of stay, disposition, and cost. In conclusion, women are significantly more likely than men to die with CIED infection. A substantial part of this excess mortality occurs after discharge. It will be important to identify and address the cause(s) of this gender difference in mortality.