Predictors of early mortality in patients age 80 and older receiving implantable defibrillators

Background: There are no upper age restrictions for implantable defibrillators (ICDs) but their benefit may be limited in patients ≥ 80 years with strong competing risks of early mortality. Risk factors for early (1-year) mortality in ICD recipients ≥ 80 years of age have not been established. Methods: Two-center retrospective cohort study to assess predictors of one-year mortality in ICD recipients ≥ 80 years of age. Results: Of 2,967 ICDs implanted in the two centers from 1990-2006, 225 (7.6%) patients were ≥80 years of age and followed-up at one of the two centers. Mean age was 83.3 ± 3.1 years and follow-up time 3.3 ± 2.6 years. Median survival was 3.6 years (95% confidence interval 2.3-4.9). Multivariate predictors of 1-year mortality included ejection fraction (EF) ≤ 20% and the absence of beta-blocker use. Actuarial 1-year mortality of ICD recipients ≥ 80 with an EF ≤ 20% was 38.2% versus 13.1% in patients 80+ years with an EF > 20% and 10.6% for patients < 80 years with an EF ≤ 20% (P < 0.001 for both). There was no significant difference in the risk of appropriate ICD therapy between those patients 80+ years with EF above and below 20%. Conclusion: In general, patients ≥ 80 years of age who meet current indications for ICD implantation live sufficiently long to warrant device implantation based on anticipated survival alone. However, those with an EF ≤ 20% have a markedly elevated 1-year mortality with no observed increase in appropriate ICD therapy, thus reducing the benefit of device implantation in this population.