Natural History Of Implantable Cardioverter-Defibrillator Implanted At Or After The Age Of 70 Years In A Veteran Population A Single Center Study

Abstract

Background: The median age of patients in major Implantable Cardioverter-defibrillator (ICD)trials (MUSTT, MADIT-I, MADIT-II, and SCD-HeFT) was 63-67 years; with only 11% ≥70 years. There is little follow-up data on patients over 70 years of age who received an ICD for primary/secondary prevention of sudden cardiac death, particularly for veterans. Objective: The aim of this study was to study the natural history of ICD implantation for veterans over 70 years of age. Methods: We retrospectively reviewed single center ICD data in 216 patients with a mean age at implantation 76 ± 4 years. The ICD indication was primary prevention in 161 patients and secondary prevention in 55 patients. The ICD indication was unavailable in 4 patients. Results: Mean duration of follow up was 1686 ± 1244 days during which 114 (52%) patients died. Of these, 31% died without receiving any appropriate ICD therapy. Overall, 60/216 (28%) received appropriate therapy and 28/216 (13%) received inappropriate therapy. Patients who had ICD implantation for secondary prophylaxis had statistically more (p= 0.02) appropriate therapies compared to patients who had ICD implantation for primary prevention. Indication for implantation and hypertension predicted appropriate therapy, while age at the time of implantation and presence of atrial fibrillation predicted inappropriate therapies. Overall, 7.7% had device related complications. Conclusions: Although 28% septuagenarians in this study received appropriate ICD therapy, they had high rates of mortality, inappropriate therapy, and device complications. ICD implantation in the elderly merits individualized consideration, with higher benefit for secondary prevention.