title: Time dependence of life-threatening ventricular tachyarrhythmias after coronary revascularization in MADIT-CRT.
abstract: 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.
authors.affiliation: Cardiology Division, University of Rochester Medical Center, Rochester, New York 14642, USA. alon.barsheshet@heart.rochester.edu
authors.forename: Alon
authors.initials: A
authors.lastname: Barsheshet
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: Craig R
authors.initials: CR
authors.lastname: Narins
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.forename: W Jackson
authors.initials: WJ
authors.lastname: Hall
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Michael
authors.initials: M
authors.lastname: Eldar
authors.forename: Victor
authors.initials: V
authors.lastname: Guetta
mesh_terms: 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