Dyssynchrony and the risk of ventricular arrhythmias

TY - JOUR

T1 - Dyssynchrony and the risk of ventricular arrhythmias

AU - Kutyifa, Valentina

AU - Pouleur, Anne-Catherine

AU - Knappe, Dorit

AU - Al-Ahmad, Amin

AU - Gibinski, Michal

AU - Wang, Paul J

AU - McNitt, Scott

AU - Merkely, Bela

AU - Goldenberg, Ilan

AU - Solomon, Scott D

AU - Moss, Arthur J

AU - Zareba, Wojciech

N1 - Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

PY - 2013/4

Y1 - 2013/4

N2 - OBJECTIVES: The aim of our study was to evaluate the relationship between left ventricular (LV) dyssynchrony and the risk of ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) trial.BACKGROUND: Intraventricular mechanical dyssynchrony might be an important factor in ventricular arrhythmogenesis by enhancing electrical heterogeneity in heart failure patients. The effects of dyssynchrony have not yet been evaluated in a large cohort of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy with defibrillator (CRT-D) patients.METHODS: LV dyssynchrony was measured at baseline and at 12-months by speckle-tracking echocardiography, defined as the standard deviation of time to peak systolic strain in 12 LV myocardial segments. The endpoint was the first VT/VF/death or VT/VF. LV dyssynchrony was evaluated in 764 left bundle branch block (LBBB) patients and in 312 non-LBBB patients.RESULTS: Baseline LV dyssynchrony was not predictive of VT/VF/death or VT/VF in LBBB or non-LBBB patients in either treatment arm. In CRT-D patients with LBBB, improvement in LV dyssynchrony over a year was associated with significantly lower incidence of VT/VF/death (p < 0.001) and VT/VF (p < 0.001) compared to ICD patients and to CRT-D patients with unchanged or worsening dyssynchrony. Among LBBB patients, 15% decrease in LV dyssynchrony was associated with lower risk of VT/VF/death (hazard ratio: 0.49, 95% confidence interval: 0.24 to 0.99, p = 0.049) and VT/VF (hazard ratio: 0.30, 95% confidence interval: 0.12 to 0.77, p = 0.009) as compared to ICD patients. Patients without LBBB receiving CRT-D did not show reduction in VT/VF/death or in VT/VF in relation to improving dyssynchrony when evaluating cumulative event rates or risk of events.CONCLUSIONS: Baseline LV dyssynchrony did not predict VT/VF/death or VT/VF in mild heart failure patients with or without LBBB. CRT-induced improvement of LV dyssynchrony was associated with significant reduction of ventricular arrhythmias in patients with LBBB.

AB - OBJECTIVES: The aim of our study was to evaluate the relationship between left ventricular (LV) dyssynchrony and the risk of ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) trial.BACKGROUND: Intraventricular mechanical dyssynchrony might be an important factor in ventricular arrhythmogenesis by enhancing electrical heterogeneity in heart failure patients. The effects of dyssynchrony have not yet been evaluated in a large cohort of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy with defibrillator (CRT-D) patients.METHODS: LV dyssynchrony was measured at baseline and at 12-months by speckle-tracking echocardiography, defined as the standard deviation of time to peak systolic strain in 12 LV myocardial segments. The endpoint was the first VT/VF/death or VT/VF. LV dyssynchrony was evaluated in 764 left bundle branch block (LBBB) patients and in 312 non-LBBB patients.RESULTS: Baseline LV dyssynchrony was not predictive of VT/VF/death or VT/VF in LBBB or non-LBBB patients in either treatment arm. In CRT-D patients with LBBB, improvement in LV dyssynchrony over a year was associated with significantly lower incidence of VT/VF/death (p < 0.001) and VT/VF (p < 0.001) compared to ICD patients and to CRT-D patients with unchanged or worsening dyssynchrony. Among LBBB patients, 15% decrease in LV dyssynchrony was associated with lower risk of VT/VF/death (hazard ratio: 0.49, 95% confidence interval: 0.24 to 0.99, p = 0.049) and VT/VF (hazard ratio: 0.30, 95% confidence interval: 0.12 to 0.77, p = 0.009) as compared to ICD patients. Patients without LBBB receiving CRT-D did not show reduction in VT/VF/death or in VT/VF in relation to improving dyssynchrony when evaluating cumulative event rates or risk of events.CONCLUSIONS: Baseline LV dyssynchrony did not predict VT/VF/death or VT/VF in mild heart failure patients with or without LBBB. CRT-induced improvement of LV dyssynchrony was associated with significant reduction of ventricular arrhythmias in patients with LBBB.

KW - Aged

KW - Bundle-Branch Block/etiology

KW - Canada

KW - Cardiac Resynchronization Therapy

KW - Cardiac Resynchronization Therapy Devices

KW - Chi-Square Distribution

KW - Defibrillators, Implantable

KW - Electric Countershock/instrumentation

KW - Europe

KW - Female

KW - Heart Failure/etiology

KW - Humans

KW - Kaplan-Meier Estimate

KW - Male

KW - Middle Aged

KW - Multivariate Analysis

KW - Proportional Hazards Models

KW - Prospective Studies

KW - Risk Assessment

KW - Risk Factors

KW - Tachycardia, Ventricular/etiology

KW - Time Factors

KW - Treatment Outcome

KW - Ultrasonography

KW - United States

KW - Ventricular Dysfunction, Left/complications

KW - Ventricular Fibrillation/etiology

KW - Ventricular Function, Left

U2 - 10.1016/j.jcmg.2012.12.008

DO - 10.1016/j.jcmg.2012.12.008

M3 - SCORING: Journal article

C2 - 23579010

VL - 6

SP - 432

EP - 444

JO - JACC-CARDIOVASC IMAG

JF - JACC-CARDIOVASC IMAG

SN - 1936-878X

IS - 4

ER -