Cardiac resynchronization therapy reduces left atrial volume and the risk of atrial tachyarrhythmias in MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy).

Abstract

OBJECTIVES:

We hypothesized that reductions in left atrial volume (LAV) with a cardiac resynchronization therapy-defibrillator (CRT-D) would translate into a subsequent reduction in the risk of atrial tachyarrhythmias (AT).

BACKGROUND:

There is limited information regarding the effect of CRT-D on the risk of AT.

METHODS:

Percent reduction in LAV at 1 year following CRT-D implantation (pre-specified as low [lowest quartile: <20% reduction in LAV] and high [≥20% reduction in LAV] response to CRT-D) were related to the risk of subsequent AT (comprising atrial fibrillation, atrial flutter, atrial tachycardia, and supraventricular tachyarrhythmias) among patients enrolled in MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy).

RESULTS:

The cumulative probability of AT 2.5 years after assessment of echocardiographic response was lowest among high LAV responders to CRT-D (3%) and significantly higher among both low LAV responders to CRT-D (9%) and implantable cardioverter-defibrillator-only patients (7%; p = 0.03 for the difference among the 3 groups). Consistently, multivariate analysis showed that high LAV responders to CRT-D experienced a significant 53% (p = 0.01) reduction in the risk of subsequent AT as compared with implantable cardioverter-defibrillator-only patients, whereas low LAV responders did not derive a significant risk reduction with CRT-D therapy (hazard ratio [HR]: 1.05 [95% confidence interval (CI): 0.54 to 2.00]; p = 0.89). Patients who developed in-trial AT experienced significant increases in the risk for both the combined endpoint of heart failure or death (HR: 2.28 [95% CI: 1.45 to 3.59]; p < 0.001) and the separate occurrence of all-cause mortality (HR: 1.89 [95% CI: 1.08 to 3.62]; p = 0.01).

CONCLUSIONS:

In the MADIT-CRT study, favorable reverse remodeling of the left atrium with CRT-D therapy was associated with a significant reduction in risk of subsequent AT. (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy [MADIT-CRT]; NCT00180271).

• Authors: Andrew Brenyo, Mark S Link, Alon Barsheshet, Arthur J Moss, Wojciech Zareba, Paul J Wang, Scott McNitt, David Huang, Elyse Foster, Mark Estes 3rd, Scott D Solomon, Ilan Goldenberg
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 58 Issue 16 Pg. 1682-9 (Oct 11 2011) ISSN: 1558-3597 [Electronic] United States
• PMID: 21982313 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Topics

• Aged
• Cardiac Resynchronization Therapy (methods)
• Defibrillators, Implantable
• Echocardiography (methods)
• Female
• Heart Atria (pathology)
• Heart Failure (therapy)
• Humans
• Male
• Middle Aged
• Multivariate Analysis
• Proportional Hazards Models
• Risk
• Tachycardia (therapy)