Is it time to consider a "time-out" before primary prevention implantable cardioverter-defibrillator placement in currently or recently hospitalized older patients with heart failure?

Background: Trajectories of mortality after primary prevention implantable cardioverter-defibrillator (ICD) placement for older patients with heart failure during or soon after acute hospitalization have not been assessed.

Objective: The purpose of this study was to compare trajectories of mortality after primary prevention ICD placement during or soon after acute cardiac or non-cardiac hospitalization.

Methods: We identified older patients with heart failure undergoing primary prevention ICD placement using 20% Medicare data (2008-2018). Placement settings were as follows: (1) Current-H-during current hospitalization, (2) Recent-H-within 90 days of hospitalization, or (3) Chronic stable. Hospitalization was categorized as cardiac vs non-cardiac. Interval mortality rates and hazard ratios (HRs) using Cox regression were estimated at 0-30, 31-90, and 91-365 days after ICD placement.

Results: Of the 61,710 patients (mean age 76 years; 35% female; 85% white), 19% (11,947), 25% (15,147), and 56% (34,616) had ICDs in Current-H, Recent-H, and Chronic stable settings. Mortality rates (per 100 person-years) were highest during 0-30 days, with 38 (34-42) and 22 (19-24) for Current-H and Recent-H, which declined to 21 (20-22) and 16 (15-17) during 91-365 days, respectively. Compared to Chronic stable, HRs were highest during 0-30 days post-ICD placement (5.5 [4.5-6.8] for Current-H and 3.4 [2.8-4.2] for Recent-H) and decreased during 91-365 days (2.0 [1.8-2.1] for Current-H and 1.6 [1.5-1.7] for Recent-H). HR pattens were similar for cardiac and non-cardiac hospitalizations.

Conclusion: Primary prevention ICD placement during or soon after hospitalization for any reason was associated with worse mortality with diminishing risks after 90 days. Hospitalization likely identifies a sicker population in whom early mortality with or without ICD may be higher. Our results support careful consideration regarding ICD placement during the 90 days after hospitalization.