Frailty, Implantable Cardioverter Defibrillators, and Mortality: a Systematic Review

Area of Science:

• Cardiology
• Geriatrics
• Public Health

Background:

• Evidence on implantable cardioverter defibrillators (ICDs) for preventing sudden cardiac death (SCD) in older adults is inconsistent.
• Age alone is not a reliable predictor of ICD benefit in this population.
• Frailty may be a key factor in identifying older adults who do not benefit from ICDs, potentially not improving overall mortality risk.

Purpose of the Study:

• To review existing literature on the association between frailty and outcomes in older adults receiving ICDs for primary prevention of SCD.
• To determine if frailty is a better predictor of ICD benefit than chronological age.

Main Methods:

• A systematic literature search was conducted across major databases (PubMed, Embase, Web of Science, Cochrane) up to January 31, 2019.
• Studies included were assessed for quality and risk of bias, with frailty defined broadly using various validated components or tools.
• Nine relevant articles, including randomized controlled trials and cohort studies, were identified and analyzed.

Main Results:

• All included studies reported higher mortality rates among individuals identified as frail, irrespective of the frailty definition used.
• One RCT indicated no benefit from ICD therapy in slow walkers after three years.
• Analysis of a large ICD registry cohort showed higher 1-year mortality post-ICD placement in frail patients or those with dementia. Four studies linked being underweight to increased mortality after ICD implantation.

Conclusions:

• Current evidence suggests that frail individuals may not experience benefits from ICD placement for the primary prevention of SCD.
• Frailty assessment could refine patient selection for ICD therapy, potentially avoiding unnecessary procedures and associated risks in this population.