Survival Benefit of ICDs Among Older Patients | Journal Scan

Study Questions:

What is the impact of patient age on the risks of death or rehospitalization after primary prevention implantable cardioverter-defibrillator (ICD) placement?


Data were pooled from five major primary prevention ICD trials: MADIT-I, MUSTT, MADIT-II, DEFINITE, and SCD-HeFT.


There were 3,530 patients. Median age at enrollment was 62 years (interquartile range, 53-70 years). Older patients had more comorbidities. In unadjusted exploratory analyses, ICD recipients were less likely to die than nonrecipients in all age groups. Sample sizes were limited among patients ages ≥75 years. In adjusted Bayesian–Weibull modeling, point estimates showed that ICD efficacy in reducing death risk persisted, but the effect was attenuated with increasing age. Using an adjusted Bayesian logistic regression model, there was no evidence of an interaction between age and ICD treatment on rehospitalization.


The authors concluded that the survival benefit of the ICD persists across age groups, but the benefit is attenuated with increasing age. This could be because of more comorbidities, competing causes of death, or limited sample size of older patients. Age did not appear to modify the association between ICD treatment and rehospitalization.


This study is important, because a significant portion of patients receiving primary prevention ICDs are older than most patients in the clinical trials, which established the indication for the ICD. The incidence of sudden death rises with increasing age, but the competing risk of nonsudden death becomes higher as well. The present data are consistent with most other databases suggesting that there is a sustained mortality benefit in patients older than 75 years old, so age per se should not be a contraindication to ICD placement. Other factors, such as comorbidities and patient preference, should inform the decision about whether to offer an ICD to those patients. Further studies are needed to assess which patients with advanced age tend to benefit more from ICD implantation.

Clinical Topics: Arrhythmias and Clinical EP, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Defibrillators, Implantable, Cause of Death, Comorbidity, Logistic Models, Primary Prevention, Risk, Hospitalization, Aging, Arrhythmias, Cardiac, Death, Sudden, Cardiac

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