Age and gender trends in implantable cardioverter defibrillator utilization: A population based study

Introduction: Implantable cardioverter-defibrillators improve mortality in selected high risk patients, yet population based data regarding utilization of these devices, particularly in the elderly, are limited. Methods: To address this, we reviewed all ICD implantations performed in Olmsted County, MN, a geographically defined population, between December 1989 and December 2004. Results: The study population comprised 179 patients (147 male, 82%, mean age 65±14 years). Baseline ejection fraction and creatinine were 35%±16% and 1.38±1.08 mg/dl, respectively. Over the study period, the incidence of congestive heart failure in patients undergoing ICD implantation and referrals for primary prevention ICDs increased, while baseline ejection fraction and etiology of cardiomyopathy remained unchanged. The incidence of ICD implantations increased significantly in the elderly (p<0.001) and especially in male patients when compared to female patients (p<0.001). Conclusions: Age of patients undergoing ICD implantation is increasing. However, fewer females compared to males are undergoing ICD implantation, suggesting a gender bias in ICD therapy and utilization.