Cardiac resynchronization therapy is associated with reductions in left atrial volume and inappropriate implantable cardioverter-defibrillator therapy in MADIT-CRT

Tyler Slyngstad; Anne-Christine Huth Ruwald; Valentina Kutyifa; Scott McNitt; Bronislava Polonsky; Scott D Solomon; Elyse Foster; Ilan Goldenberg; Paul J Wang; Helmut Klein; Wojciech Zareba; Arthur J Moss

doi:10.1016/j.hrthm.2014.01.033

Cardiac resynchronization therapy is associated with reductions in left atrial volume and inappropriate implantable cardioverter-defibrillator therapy in MADIT-CRT

Heart Rhythm. 2014 Jun;11(6):1001-7. doi: 10.1016/j.hrthm.2014.01.033. Epub 2014 Feb 4.

Affiliations

¹ Heart Research Follow-up Program of the of the Department of Medicine, University of Rochester Medical Center, Rochester, New York.
² Heart Research Follow-up Program of the of the Department of Medicine, University of Rochester Medical Center, Rochester, New York; Gentofte University Hospital, Department of Cardiology, Copenhagen, Denmark.
³ Brigham and Women's Hospital, Boston, Massachusetts.
⁴ University of California San Francisco Hospital, San Francisco, California.
⁵ Sheba Medical Center and Tel Aviv University, Tel Aviv, Israel.
⁶ Cardiology Division, Stanford University School of Medicine, Palo Alto, California.
⁷ Heart Research Follow-up Program of the of the Department of Medicine, University of Rochester Medical Center, Rochester, New York. Electronic address: heartajm@heart.rochester.edu.

PMID: 24502968
DOI: 10.1016/j.hrthm.2014.01.033

Abstract

Background: There are no prior studies assessing the relationship between left atrial volume (LAV) and inappropriate implantable cardioverter-defibrillator (ICD) therapy following treatment with cardiac resynchronization therapy.

Objective: The purpose of this study was to investigate the hypothesis that patients randomized to cardiac resynchronization therapy with defibrillator (CRT-D) in the Multicenter Automatic Defibrillator Trial-Cardiac Resynchronization Therapy (MADIT-CRT) who had significant LAV reductions would have reduced risks of inappropriate ICD therapy.

Methods: Cardiac resynchronization remodeling was assessed by measuring LAV change between baseline and 12-month echocardiograms in 751 CRT-D treated patients. Patients were stratified into quartiles based on percent reduction of LAV change. High LAV responders were those in the highest 3 quartiles of LAV reduction (LAV reduction ≥21%). Low LAV responders were those in the lowest quartile of LAV reduction (LAV reduction <21%). Clinical factors associated with ≥21% reduction in LAV were evaluated by linear regression analysis.

Results: In Cox proportional hazards regression analyses, high LAV responders had a 39% reduction in the risk of inappropriate therapy (hazard ratio 0.61, P = .04) and left bundle branch block patients exhibited an even greater risk reduction in inappropriate therapy (hazard ratio 0.51, P = .02) compared to low LAV responders during follow-up extending up to 3 years after the 12-month echocardiogram. High LAV responders also had a significantly lower risk of heart failure or death during follow-up than did low LAV responders.

Conclusion: A ≥21% reduction in LAV with cardiac resynchronization therapy is associated with significant reductions in inappropriate ICD therapy and in heart failure or death during a 3-year follow-up.

Trial registration: ClinicalTrials.gov NCT00180271.

Keywords: Cardiac resynchronization therapy; Echocardiography; Inappropriate implantable cardioverter-defibrillator therapy; Left atrial volume.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Atrial Fibrillation / pathology
Atrial Fibrillation / therapy*
Cardiac Resynchronization Therapy* / adverse effects
Cardiac Resynchronization Therapy* / methods
Defibrillators, Implantable* / statistics & numerical data
Female
Heart Atria / pathology
Humans
Male
Middle Aged
Organ Size
Tachycardia, Ventricular / etiology

Associated data

ClinicalTrials.gov/NCT00180271