Arrhythmic and Mortality Outcomes Among Ischemic Versus Nonischemic Cardiomyopathy Patients Receiving Primary ICD Therapy.

Abstract

OBJECTIVES:

This study sought to determine the association of cardiomyopathy etiology with the likelihood of ventricular arrhythmias, appropriate implantable cardioverter-defibrillator (ICD) therapy, and mortality.

BACKGROUND:

There are conflicting data on the benefit of primary prevention ICD therapy in patients with ischemic versus nonischemic cardiomyopathy (ICM/NICM).

METHODS:

The study population comprised 4803 patients with ICM (n = 3,106) or NICM (n = 1,697) with a primary prevention ICD enrolled in 5 randomized trials conducted between 1997 and 2017. The primary end point was sustained ventricular tachycardia (VT) ≥200 beats/min or ventricular fibrillation (VF). Secondary end points included appropriate ICD therapy and all-cause mortality. Differences in cause-specific mortality, including noncardiac, sudden cardiac, and non-sudden cardiac death, were also examined.

RESULTS:

Patients with ICM were significantly older and had more comorbid conditions, whereas those with NICM had a more advanced heart failure class at enrollment and were more often prescribed medical or cardiac resynchronization therapy for heart failure. Multivariate analysis showed that ICM versus NICM had a similar risk of VT/VF events (HR: 0.98 [95% CI: 0.79-1.20]) and appropriate ICD therapy (HR: 1.03 [95% CI: 0.87-1.22]), whereas the risk of all-cause mortality was 1.8-fold higher among ICM versus NICM patients (HR: 1.84 [95% CI: 1.42-2.38]), dominated by non-sudden cardiac mortality.

CONCLUSIONS:

Combined data from 5 landmark ICD clinical trials show that ICM patients experience a similar risk of life-threatening ventricular arrhythmic events but have an increased risk of all-cause mortality, dominated by non-sudden cardiac death, compared with NICM patients.

• Authors: Craig R Narins, Mehmet K Aktas, Anita Y Chen, Scott McNitt, Fred S Ling, Arwa Younis, Wojciech Zareba, James P Daubert, David T Huang, Spencer Rosero, Valentina Kutyifa, Ilan Goldenberg
• Journal: JACC. Clinical electrophysiology (JACC Clin Electrophysiol) Vol. 8 Issue 1 Pg. 1-11 (01 2022) ISSN: 2405-5018 [Electronic] United States
• PMID: 34454875 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Topics

• Arrhythmias, Cardiac (therapy)
• Cardiac Resynchronization Therapy
• Cardiomyopathies (therapy)
• Defibrillators, Implantable
• Humans
• Tachycardia, Ventricular (therapy)