Implantable Cardioverter-Defibrillators Among Older Survivors of Out-of-Hospital Cardiac Arrest

Although current guidelines recommend implantable cardioverter-defibrillator (ICD) placement in survivors of out-of-hospital cardiac arrest, contemporary data on secondary-prevention ICDs in survivors of out-of-hospital cardiac arrest remain limited.

Using 2013 to 2019 CARES (Cardiac Arrest Registry to Enhance Survival) linked to Medicare, we identified 3226 patients aged ≥65 years with an initial shockable rhythm who survived to discharge without severe neurological disability. Multivariable hierarchical regression models were used to examine the association between patient variables and ICD placement and quantify hospital variation in ICD implantation. The mean age was 72.2 years, 23.5% were women, 10% were Black individuals, and 4% were Hispanic individuals. Overall, 997 (30.9%) patients received an ICD before discharge, 1266 (39.2%) at 90 days, and 1287 (39.9%) within 6 months. Older age (≥85 years), female sex, history of diabetes, calendar year, and presentation with acute myocardial infarction were associated with lower odds of ICD implantation, but race or ethnicity was not associated with ICD implantation. Among 297 hospitals, the median proportion of survivors receiving ICD at discharge was 28.6% (interquartile range, 20%-50%). The relative odds of ICD implantation varied by 62% across hospitals (median odds ratio, 1.62 [95% CI, 1.38-1.82]) after adjusting for case mix.

Fewer than 1 in 3 survivors of out-of-hospital cardiac arrest due to a shockable rhythm received a secondary-prevention ICD before discharge. Although patient variables were associated with ICD implantation, there was no difference by race or ethnicity. Even after adjusting for patient case mix, ICD implantation varied markedly across hospitals.