Clinical Research
Heart Rhythm Disorders
Appropriateness of Primary Prevention Implantable Cardioverter-Defibrillators at the Time of Generator Replacement: Are Indications Still Met?

https://doi.org/10.1016/j.jacc.2014.03.025Get rights and content
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Objectives

This study sought to determine how often patients with primary prevention implantable cardioverter-defibrillators (ICDs) meet guideline-derived indications at the time of generator replacement.

Background

Professional societies have developed guideline criteria for the appropriate implantation of an ICD for the primary prevention of sudden cardiac death. It is unknown whether patients continue to meet criteria when their devices need replacement for battery depletion.

Methods

We performed a retrospective chart review of patients undergoing replacement of primary prevention ICDs at 2 tertiary Veterans Affairs Medical Centers. Indications for continued ICD therapy at the time of generator replacement included a left ventricular ejection fraction (LVEF) ≤35% or receipt of appropriate device therapy.

Results

In our cohort of 231 patients, 59 (26%) no longer met guideline-driven indications for an ICD at the time of generator replacement. An additional 79 patients (34%) had not received any appropriate ICD therapies and had not undergone reassessment of their LVEF. Patients with an initial LVEF of 30% to 35% were less likely to meet indications for ICD therapy at the time of replacement (odds ratio: 0.52; 95% confidence interval: 0.30 to 0.88; p = 0.01). Patients without ICD indications subsequently received appropriate ICD therapies at a significantly lower rate than patients with indications (2.8% vs. 10.7% annually, p < 0.001). If ICD generator explantations were performed instead of replacements in the patients without ICD indications, the cost savings would be $1.6 million.

Conclusions

Approximately 25% of patients who receive primary prevention ICDs may no longer meet guideline indications for ICD use at the time of generator replacement, and these patients receive subsequent ICD therapies at a significantly lower rate.

Key Words

ICD generator replacement
implantable cardioverter-defibrillator
sudden cardiac death

Abbreviations and Acronyms

CPRS
Computerized Patient Records System
CPT
Current Procedural Technology
CRT
cardiac resynchronization therapy
CRT-D
cardiac resynchronization therapy with a defibrillator
CRT-P
cardiac resynchronization therapy without a defibrillator
ICD
implantable cardioverter-defibrillator
ICM
ischemic cardiomyopathy
LVEF
left ventricular ejection fraction
NICM
nonischemic cardiomyopathy
SCD
sudden cardiac death
VA
Veterans Affairs

Cited by (0)

Dr. Epstein has received honoraria from Boston Scientific, Medtronic, and St. Jude Medical; and research grants from Biotronik, Boston Scientific, Medtronic, and St. Jude Medical. Dr. Dixit has received a research grant from Medtronic. Dr. Deo has received support from grant number K23DK089118 from the National Institutes of Health. Drs. Epstein, Bala, Riley, Deo, and Dixit have received fellowship support from Boston Scientific, Medtronic, and St. Jude Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.