title: Reverse remodeling and the risk of ventricular tachyarrhythmias in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy).
abstract: OBJECTIVE
  We aimed to evaluate the relationship between echocardiographic response to cardiac resynchronization therapy (CRT) and the risk of subsequent ventricular tachyarrhythmias (VTAs).
  
  
  BACKGROUND
  Current data regarding the effect of CRT on the risk of VTA are limited and conflicting.
  
  
  METHODS
  The risk of a first appropriate implantable cardioverter-defibrillator (ICD) therapy for VTA (including ventricular tachycardia, ventricular fibrillation, and ventricular flutter) was compared between high- and low-echocardiographic responders to CRT defibrillator (CRT-D) therapy (defined as ≥ 25% and <25% reductions, respectively, in left ventricular end-systolic volume [LVESV] at 1 year compared with baseline) and ICD-only patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy).
  
  
  RESULTS
  The cumulative probability of a first VTA at 2 years after assessment of echocardiographic response was highest among low responders to CRT-D (28%), intermediate among ICD-only patients (21%), and lowest among high responders to CRT-D (12%), with p < 0.001 for the overall difference during follow-up. Multivariate analysis showed that high responders to CRT-D experienced a significant 55% reduction in the risk of VTA compared with ICD-only patients (p < 0.001), whereas the risk of VTA was not significantly different between low responders and ICD-only patients (hazard ratio [HR]: 1.26; p = 0.21). Consistently, assessment of response to CRT-D as a continuous measure showed that incremental 10% reductions in left ventricular end-systolic volume were associated with corresponding reductions in the risk of subsequent VTA (HR: 0.80; p < 0.001), VTA/death (HR: 0.79; p < 0.001), ventricular tachycardia (HR: 0.80; p < 0.001), and ventricular fibrillation/ventricular flutter (HR: 0.75; p = 0.044).
  
  
  CONCLUSIONS
  In patients with left ventricular dysfunction enrolled in the MADIT-CRT trial, reverse remodeling was associated with a significant reduction in the risk of subsequent life-threatening VTAs. (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy [MADIT-CRT]; NCT00180271).
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: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Scott D
authors.initials: SD
authors.lastname: Solomon
authors.forename: Amin
authors.initials: A
authors.lastname: Al-Ahmad
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Elyse
authors.initials: E
authors.lastname: Foster
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.forename: Helmut U
authors.initials: HU
authors.lastname: Klein
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Michael
authors.initials: M
authors.lastname: Eldar
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
mesh_terms: D017677:Age Distribution; D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D020257:Ventricular Remodeling