Cardiac Resynchronization Defibrillator Therapy for Nonspecific Intraventricular Conduction Delay Versus Right Bundle Branch Block.

Abstract

BACKGROUND:

The benefits of cardiac resynchronization therapy (CRT) in patients with non-left bundle branch block (LBBB) conduction abnormality have not been fully explored.

OBJECTIVES:

This study sought to evaluate clinical outcomes among Medicare-aged patients with nonspecific intraventricular conduction delay (NICD) versus right bundle branch block (RBBB) in patients eligible for implantation with a CRT with defibrillator (CRT-D).

METHODS:

Using the National Cardiovascular Data Registry implantable cardioverter-defibrillator (ICD) registry data between 2010 and 2013, the authors compared outcomes in CRT-eligible patients implanted with CRT-D versus ICD-only therapy among patients with NICD and RBBB. Also, among all CRT-D-implanted patients, the authors compared outcomes in those with NICD versus RBBB. Survival curves and multivariable adjusted hazard ratios (HRs) were used to assess outcomes including hospitalization and death.

RESULTS:

In 11,505 non-LBBB CRT-eligible patients, after multivariable adjustment, among patients with RBBB, CRT-D was not associated with better outcomes, compared with ICD alone, regardless of QRS duration. Among patients with NICD and a QRS ≥150 ms, CRT-D was associated with decreased mortality at 3 years compared with ICD alone (HR: 0.602; 95% confidence interval [CI]: 0.416 to 0.871; p = 0.0071). Among 5,954 CRT-D-implanted patients, after multivariable adjustment NICD compared with RBBB was associated with lower mortality at 3 years in those with a QRS duration of ≥150 ms (HR: 0.757; 95% CI: 0.625 to 0.917; p = 0.0044).

CONCLUSIONS:

Among non-LBBB CRT-D-eligible patients, CRT-D implantation was associated with better outcomes compared with ICD alone specifically in NICD patients with a QRS duration of ≥150 ms. Careful patient selection should be considered for CRT-D implantation in patients with non-LBBB conduction.

• Authors: Hiro Kawata, Haikun Bao, Jeptha P Curtis, Karl E Minges, Teferi Mitiku, Ulrika Birgersdotter-Green, Gregory K Feld, Jonathan C Hsu
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 73 Issue 24 Pg. 3082-3099 (06 25 2019) ISSN: 1558-3597 [Electronic] United States
• PMID: 31221257 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Topics

• Aged
• Bundle-Branch Block (diagnosis, epidemiology, physiopathology, therapy)
• Cardiac Conduction System Disease (diagnosis, epidemiology, physiopathology, therapy)
• Cardiac Resynchronization Therapy (adverse effects, methods, statistics & numerical data)
• Defibrillators, Implantable (statistics & numerical data)
• Electric Countershock (instrumentation, methods)
• Electrocardiography (methods)
• Female
• Heart Ventricles (physiopathology)
• Humans
• Male
• Medicare (statistics & numerical data)
• Outcome and Process Assessment, Health Care
• Patient Selection
• Registries
• United States (epidemiology)