Relationship between improvement in left ventricular dyssynchrony and contractile function and clinical outcome with cardiac resynchronization therapy: the MADIT-CRT trial

TY - JOUR

T1 - Relationship between improvement in left ventricular dyssynchrony and contractile function and clinical outcome with cardiac resynchronization therapy: the MADIT-CRT trial

AU - Pouleur, Anne-Catherine

AU - Knappe, Dorit

AU - Shah, Amil M

AU - Uno, Hajime

AU - Bourgoun, Mikhail

AU - Foster, Elyse

AU - McNitt, Scott

AU - Hall, W Jackson

AU - Zareba, Wojciech

AU - Goldenberg, Ilan

AU - Moss, Arthur J

AU - Pfeffer, Marc A

AU - Solomon, Scott D

AU - MADIT-CRT Investigators

PY - 2011/7

Y1 - 2011/7

N2 - AIMS: To assess long-term effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) dyssynchrony and contractile function, by two-dimensional speckle-tracking echocardiography, compared with implantable cardioverter defibrillator (ICD) only in MADIT-CRT.METHODS AND RESULTS: We studied 761 patients in New York Heart Association I/II, ejection fraction ≤30%, and QRS ≥130 ms [n = 434, CRT-defibrillator (CRT-D), n = 327, ICD] with echocardiographic studies available at baseline and 12 months. Dyssynchrony was determined as the standard deviation of time to peak transverse strain between 12 segments of apical four- and two-chamber views, and contractile function as global longitudinal strain (GLS) by averaging longitudinal strain over these 12 segments. We compared changes in LV dyssynchrony and contractile function between treatment groups and assessed relationships between these changes over the first year and subsequent outcomes (median post 1-year follow-up = 14.9 months). Mean changes in LV dyssynchrony and contractile function measured by GLS in the overall population were, respectively, -29 ± 83 ms and -1 ± 2.9%. However, both LV dyssynchrony (CRT-D: -47 ± 83 ms vs. ICD: -6 ± 76 ms, P < 0.001) and contractile function (CRT-D: -1.4 ± 3.1% vs. ICD: -0.4 ± 2.5%, P < 0.001) improved to a greater extent in the CRT-D group compared with the ICD-only group. A greater improvement in dyssynchrony and contractile function at 1 year was associated with lower rates of the subsequent primary outcome of death or heart failure, adjusting for baseline dyssynchrony and contractile function, treatment arm, ischaemic status, and change in LV end-systolic volume. Each 20 ms decrease in LV dyssynchrony was associated with a 7% reduction in the primary outcome (P = 0.047); each 1% improvement in GLS over the 12-month period was associated with a 24% reduction in the primary outcome (P < 0.001).CONCLUSION: Cardiac resynchronization therapy resulted in a significant improvement in both LV dyssynchrony and contractile function measured by GLS compared with ICD only and these improvements were associated with better subsequent outcomes.

AB - AIMS: To assess long-term effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) dyssynchrony and contractile function, by two-dimensional speckle-tracking echocardiography, compared with implantable cardioverter defibrillator (ICD) only in MADIT-CRT.METHODS AND RESULTS: We studied 761 patients in New York Heart Association I/II, ejection fraction ≤30%, and QRS ≥130 ms [n = 434, CRT-defibrillator (CRT-D), n = 327, ICD] with echocardiographic studies available at baseline and 12 months. Dyssynchrony was determined as the standard deviation of time to peak transverse strain between 12 segments of apical four- and two-chamber views, and contractile function as global longitudinal strain (GLS) by averaging longitudinal strain over these 12 segments. We compared changes in LV dyssynchrony and contractile function between treatment groups and assessed relationships between these changes over the first year and subsequent outcomes (median post 1-year follow-up = 14.9 months). Mean changes in LV dyssynchrony and contractile function measured by GLS in the overall population were, respectively, -29 ± 83 ms and -1 ± 2.9%. However, both LV dyssynchrony (CRT-D: -47 ± 83 ms vs. ICD: -6 ± 76 ms, P < 0.001) and contractile function (CRT-D: -1.4 ± 3.1% vs. ICD: -0.4 ± 2.5%, P < 0.001) improved to a greater extent in the CRT-D group compared with the ICD-only group. A greater improvement in dyssynchrony and contractile function at 1 year was associated with lower rates of the subsequent primary outcome of death or heart failure, adjusting for baseline dyssynchrony and contractile function, treatment arm, ischaemic status, and change in LV end-systolic volume. Each 20 ms decrease in LV dyssynchrony was associated with a 7% reduction in the primary outcome (P = 0.047); each 1% improvement in GLS over the 12-month period was associated with a 24% reduction in the primary outcome (P < 0.001).CONCLUSION: Cardiac resynchronization therapy resulted in a significant improvement in both LV dyssynchrony and contractile function measured by GLS compared with ICD only and these improvements were associated with better subsequent outcomes.

KW - Aged

KW - Cardiac Resynchronization Therapy

KW - Defibrillators, Implantable

KW - Echocardiography

KW - Female

KW - Heart Failure/physiopathology

KW - Humans

KW - Male

KW - Middle Aged

KW - Myocardial Contraction/physiology

KW - Treatment Outcome

KW - Ventricular Dysfunction, Left/physiopathology

U2 - 10.1093/eurheartj/ehr185

DO - 10.1093/eurheartj/ehr185

M3 - SCORING: Journal article

C2 - 21609974

VL - 32

SP - 1720

EP - 1729

JO - EUR HEART J

JF - EUR HEART J

SN - 0195-668X

IS - 14

ER -