Time dependence of life-threatening ventricular tachyarrhythmias after coronary revascularization in MADIT-CRT.
BACKGROUND
Coronary revascularization (CR) may confer electrical stability in patients with ischemic cardiomyopathy. However, data regarding the effect of CR on the development of ventricular tachyarrhythmias in this population are limited.


OBJECTIVE
The purpose of this study was to evaluate the association between CR and arrhythmic risk in postmyocardial infarction (post-MI) patients with left ventricular dysfunction.


METHODS
The risk for life-threatening ventricular tachyarrhythmias (defined as a first appropriate defibrillator therapy for ventricular tachycardia [VT]/ventricular fibrillation [VF] or death) was compared between post-MI patients with and those without prior CR (n = 612 and 147, respectively) enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT).


RESULTS
The 3-year cumulative rate of VT/VF or death was significantly higher among patients without prior CR (42%) than in patients who underwent prior CR (32%, P = .02). Multivariate analysis demonstrated that patients without prior CR had 48% increased risk (P = .01) for VT/VF or death. Risk reduction associated with CR was related to elapsed time from CR, assessed both as a categorical variable (tertiles for time from CR: ≥7 years, hazard ratio [HR] = 1.93, P = .001; 1.5-7 years, HR = 1.70, P = .01 vs <1.5 years) and as a continuous measure (4%, P = .002, increased risk for VT/VF or death per 1-year increment of elapsed time from CR). The effect of CR on arrhythmic risk was similar in patients treated with a defibrillator alone or when combined with cardiac resynchronization therapy.


CONCLUSIONS
Post-MI patients with left ventricular dysfunction who undergo CR experience a time-dependent reduction in the risk for subsequent life-threatening ventricular tachyarrhythmias.
Barsheshet
Alon
A
Cardiology Division, University of Rochester Medical Center, Rochester, New York 14642, USA. alon.barsheshet@heart.rochester.edu
Goldenberg
Ilan
I
Narins
Craig R
CR
Moss
Arthur J
AJ
McNitt
Scott
S
Wang
Paul J
PJ
Huang
David T
DT
Hall
W Jackson
WJ
Zareba
Wojciech
W
Eldar
Michael
M
Guetta
Victor
V
D000368:Aged; D058406:Cardiac Resynchronization Therapy; D009202:Cardiomyopathies / Q000150:complications; D001026:Coronary Artery Bypass; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000601:surgery*; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000517:prevention & control* / Q000628:therapy; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000150:complications; D014693:Ventricular Fibrillation / Q000209:etiology / Q000517:prevention & control / Q000628:therapy