Complication rates of ICDs higher in the elderly, but mainly due to comorbidities

Elderly patients have higher rates of complications after implantable cardioverter defibrillator (ICD) placement compared with younger patients, but mainly due to increased comorbid conditions, and the risks of the procedure are still acceptable, a new study has found.

Researchers used data from the National Cardiovascular Data Registry's ICD Registry to try to determine ICD complication rates by decade of age in elderly patients. Previous studies, they said, have used only one age cutoff to define “elderly” and may not have detected differences in complication rates among patients in their sixties, seventies, eighties and nineties. A total of 150,264 patients who received ICDs for primary prevention between January 2006 and December 2008 were included. The study's primary end point was any adverse event or death in the hospital, while the secondary end points were major and minor adverse events and length of stay. The study results were published online Aug. 30 by Circulation: Cardiovascular Quality and Outcomes.

Of the study patients, 91,863 (61%) were 65 years of age or older. Patients in this age group were more likely than younger patients to have diabetes, atrial fibrillation, congestive heart failure, renal disease, and coronary artery disease. A total of 3.4% of the entire study cohort experienced a complication after ICD implantation: 2.8% of patients younger than 65, 3.1% of patients 65 to 69 years old, 3.5% of patients 70 to 74 years old, 3.9% of patients 75 to 79 years old, 4.5% of patients 80 to 84 years old, and 4.5% of patients at least 85 years old. In multivariate analysis after adjustment for clinical covariates, the authors found that the risk for any adverse event or death compared with patients younger than 65 was 1.14 (95% CI, 1.03 to 1.25) in those 75 to 79 years old, 1.22 (95% CI, 1.10 to 1.36) in those 80 to 84 years old, and 1.15 (95% CI, 1.01 to 1.32) in those 85 years old and older. Age did not predict complications as well as some other factors did, including sex, renal failure, stage IV heart failure, atrial fibrillation, second- or third-degree atrioventricular block, and biventricular ICD placement.

The study examined only adverse events that occurred in the hospital and did not include complications related to leads, among other limitations. However, the authors concluded, “Older patients had a modestly increased—but acceptably safe—risk of periprocedural complications and in-hospital mortality, driven mostly by increased comorbidity.” The authors stressed that their findings do not indicate that elderly patients should not receive ICDs but rather provide data on complication rates by age that will help improve informed decision making.