Title: Meta-Analysis: Age and Effectiveness of Prophylactic Implantable Cardioverter-Defibrillators
Date Posted: December 1, 2010
Authors: Santangeli P, Di Biase L, Russo AD, et al.
Citation: Ann Intern Med 2010;153:592-599.
Do implantable cardioverter-defibrillators (ICDs) improve survival in elderly patients when used for primary prevention of sudden death?
This was a meta-analysis of five primary prevention randomized ICD trials (MADIT-II, DINAMIT, DEFINITE, SCD-HeFT, and IRIS) that included 5,783 patients with an ejection fraction ≤40% and a primary prevention indication for an ICD. Elderly patients (defined as ages >60-65 years) accounted for 44% of the overall study population. The primary endpoint was the survival benefit of prophylactic ICD therapy compared to optimal medical therapy.
In patients <60-65 years of age, ICD therapy was associated with a significant decrease of 35% in all-cause mortality. In contrast, the decrease in mortality with ICD therapy in elderly patients was 19% and not statistically significant.
The authors concluded that prophylactic ICD therapy does not improve survival in elderly patients to the same extent as in younger patients.
None of the primary prevention ICD trials was designed to determine whether age influences the extent to which ICD therapy improves survival. Nevertheless, it is noteworthy that post-hoc analysis of the MADIT-II trial showed no significant difference in ICD survival benefit between patients older and younger than 75 years of age. The results of the present study are provocative and should stimulate further evaluation of the interaction between age and prophylactic ICD therapy. However, it would be inappropriate to stop implanting ICDs in elderly patients based only on the results of this meta-analysis, particularly when the definition of ‘elderly’ was an age cut-off of only 60-65 years.
Fred Morady, M.D., F.A.C.C.
POSTED BY STEVEN ALMANY, MD