Survival Probability and Survival Benefit Associated With Primary Prevention Implantable Cardioverter-Defibrillator...

Area of Science:

• Cardiology
• Medical Devices
• Health Outcomes Research

Background:

• Implantable cardioverter-defibrillators (ICDs) are used for primary prevention (PP) of sudden cardiac death.
• Patient benefit from generator changes (GCs) in ICDs with PP indications varies.
• Improved predictors for post-GC outcomes are needed.

Purpose of the Study:

• To identify predictors of survival and survival benefit after generator changes (GCs) in patients with initial primary prevention (PP) implantable cardioverter-defibrillators (ICDs).
• To compare survival outcomes between patients undergoing GCs and control heart failure patients without ICDs.

Main Methods:

• Analysis of the National Cardiovascular Data Registry ICD Registry data from 2012-2016.
• Inclusion of patients undergoing GCs of initial non-cardiac resynchronization therapy PP ICDs.
• Assessment of predictors including Seattle Heart Failure Model (SHFM) predicted annual mortality, left ventricular ejection fraction (LVEF) >35%, and proportional risk of arrhythmic death (PRAD).

Main Results:

• In 40,933 patients undergoing GCs, SHFM-predicted annual mortality was the strongest predictor of decreased post-GC survival.
• Patients with LVEF >35% undergoing GCs had worse SHFM-adjusted survival compared to controls.
• In patients with LVEF ≤35%, worse survival was observed in 21% with PRAD <43%, while improved survival was seen in 10% with PRAD >65%.

Conclusions:

• Patients receiving ICD GCs for primary prevention with LVEF >35% alone showed worse survival versus controls.
• Patients with LVEF ≤35% and PRAD <43% also exhibited worse survival post-GC compared to controls.
• These findings highlight specific patient subgroups who may not benefit from or could be harmed by ICD GCs.