Outcome of women versus men with ventricular tachyarrhythmias treated with the implantable cardioverter defibrillator.

INTRODUCTION: Important sex differences in the incidence and outcome of patients with ischemic heart disease, the leading cause of ventricular tachyarrhythmias, have been identified. Implantable cardioverter defibrillator (ICD) therapy has become the treatment of choice for patients with ventricular tachycardia (VT) and ventricular fibrillation (VF), but little is known about gender differences in the outcome of ICD-treated patients. METHODS AND
RESULTS: In this retrospective study, we compared arrhythmic events and survival of 376 women and 1,654 men treated with an ICD as part of prospective evaluations of transvenous devices or lead systems. Women were younger (62+/-14 years vs 65+/-12 years, P = 0.0005), had higher left ventricular ejection fraction (0.36+/-0.15 vs 0.32+/-0.13, P < 0.0001), were more likely to present with VF (34% vs 19%, P < 0.001), and had lower implantation defibrillation threshold (11+/-6 vs 13+/-6 J, P < 0.0001). Implant complication rates were similar in men and women (2.6% vs 3.5%, P = 0.46). The 1-year and 2-year cumulative rates of appropriate ICD therapies were 31.4% and 38.4% for men and 32.6% and 40.8% for women, respectively (P = 0.63). The unadjusted 1-year and 2-year cumulative survival rates were 95.6% and 93.7% for men and 95.7% and 94.3% for women, respectively (P = 0.98). Adjusted total (P = 0.61), sudden (P = 0.82), and cardiac (P = 0.34) death-free survivals also were similar in men and women.
CONCLUSION: Despite clinical differences suggesting women are at lower risk than men, men and women with VT/VF who are treated with an ICD have similar arrhythmic event and survival rates. These factors should be considered when determining risk and prescription of ICD therapy for women.