Effect of Age on Survival and Causes of Death After Primary Prevention Implantable Cardioverter-Defibrillator Implantation

The benefit of implantable cardioverter-defibrillators (ICDs) remains controversial in elderly patients and may be attenuated by a greater risk of nonarrhythmic death. We examined the effect of age on outcomes after prophylactic ICD implantation. All patients with coronary artery disease or dilated cardiomyopathy implanted with an ICD for primary prevention of sudden cardiac death in 12 French medical centers were included in a retrospective observational study. The 5,534 ICD recipients were divided according to age: 18 to 59 years (n = 2,139), 60 to 74 years (n = 2,693), and ≥75 years (n = 702). Greater prevalences of coronary artery disease and atrial fibrillation at the time of implant were observed with increasing age (both p <0.0001). During a mean follow-up of 3.1 ± 2.0 years, the annual mortality rate increased with age: 3.1% per year for age 18 to 59 years, 5.7% per year for age 60 to 74 years, and 7.5% per year for age ≥75 years (p <0.001). Older age was independently associated with a greater risk of death (adjusted odds ratio 1.43, 95% confidence interval 1.14 to 1.80 for age 60 to 74 years; and adjusted odds ratio 1.65, 95% confidence interval 1.22 to 2.22 for age >75 years). Proportions of cardiac deaths (55.2%, 57.6%, and 57.0%, p = 0.84), including ICD-unresponsive sudden death (9.9%, 6.0%, and 10.6%, p = 0.08), and rates of appropriate ICD therapies were similar in the 3 age groups. Older age was independently associated with a higher rate of early complications and a lower rate of inappropriate therapies. In conclusion, older patients exhibited higher global mortality after ICD implantation for primary prevention, whereas rates of sudden deaths and of appropriate device therapies were similar across age groups.