Author + information
- Received May 22, 2019
- Revision received July 29, 2019
- Accepted August 9, 2019
- Published online October 2, 2019.
- Saadia Sherazi, MD, MS∗ (, )
- Fatima Shah,
- Valentina Kutyifa, MD, PhD,
- Scott McNitt, MS,
- Mehmet K. Aktas, MD,
- Bronislava Polonsky, MS,
- Wojciech Zareba, MD, PhD and
- Ilan Goldenberg, MD
- ↵∗Address for correspondence:
Dr. Saadia Sherazi, Department of Cardiology, University of Rochester Medical Center, 265 Crittenden Boulevard, Box 653, Rochester, New York 14642.
Objectives This study assessed the arrhythmic risk of cardiac resynchronization therapy (CRT) patients who improved beyond Heart Rhythm Society/European Society of Cardiology guidelines for an implantable cardioverter-defibrillator (ICD) (ischemic cardiomyopathy: left ventricular ejection fraction [LVEF] >35% or New York Heart Association [NYHA] functional class I and if LVEF was 31% to 35%; nonischemic cardiomyopathy: LVEF >35% or NYHA functional class I and if LVEF was ≤35%).
Background It is currently unknown whether protection with a defibrillator is still warranted in patients who respond to CRT.
Methods This study compared the risk of ICD therapy for any ventricular tachyarrhythmia (VTA) and for fast VTA (≥ 200 beats/min) among patients implanted with a CRT with a defibrillator (CRT-D) in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy) study (N = 734) who improved at 1 year beyond guideline recommendations for primary ICD therapy (group A) with those who remained within guideline recommendations for an ICD at 1 year (group B).
Results Most patients implanted with a CRT-D device improved at 1 year beyond guideline indications for an ICD (90%). Multivariate analysis showed lower risks for any VTA and fast VTA among group A patients versus group B patients (57% risk reduction; p = 0.0006 and 46% risk reduction; p = 0.068, respectively). However, the 2-year rates of any VTA and fast VTA among CRT patients who improved beyond guidelines indications for an ICD was still substantial (VTA: 13% and 29%, and fast VTA: 7% and 16%, respectively).
Conclusions Most patients with mild heart failure implanted with a CRT device experience an improvement in left ventricular function and/or NYHA functional class beyond guideline recommendations for primary ICD therapy. However, despite this pronounced CRT response, there remains a substantial VTA risk, and protection with a defibrillator may still be warranted in this population.
MADIT-CRT was sponsored by an unrestricted research grant from Boston Scientific to the University of Rochester Medical Center. Dr. Kutyifa has received research grants from Boston Scientific, Biotronik, and Zoll; and has received consultancy honoraria from Biotronik and Zoll. Dr. Goldenberg has received an unrestricted research grant from Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received May 22, 2019.
- Revision received July 29, 2019.
- Accepted August 9, 2019.
- 2019 American College of Cardiology Foundation
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