title: Predictors of response to cardiac resynchronization therapy in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT).
abstract: BACKGROUND
  We hypothesized that combined assessment of factors that are associated with favorable reverse remodeling after cardiac resynchronization-defibrillator therapy (CRT-D) can be used to predict clinical response to the device.
  
  
  RESULTS
  The study population comprised 1761 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). Best-subset regression analysis was performed to identify factors associated with echocardiographic response (defined as percent reduction in left ventricular end-diastolic volume 1 year after CRT-D implantation) and to create a response score. Cox proportional hazards regression analysis was used to evaluate the CRT-D versus defibrillator-only reduction in the risk of heart failure or death by the response score. Seven factors were identified as associated with echocardiographic response to CRT-D and made up the response score (female sex, nonischemic origin, left bundle-branch block, QRS ≥150 milliseconds, prior hospitalization for heart failure, left ventricular end-diastolic volume ≥125 mL/m(2), and left atrial volume <40 mL/m(2)). Multivariate analysis showed a 13% (P<0.001) increase in the clinical benefit of CRT-D per 1-point increment in the response score (range, 0-14) and a significant direct correlation between risk reduction associated with CRT-D and response score quartiles: Patients in the first quartile did not derive a significant reduction in the risk of heart failure or death with CRT-D (hazard ratio=0.87; P=0.52); patients in the second and third quartiles derived 33% (P=0.04) and 36% (P=0.03) risk reductions, respectively; and patients in the upper quartile experienced a 69% (P<0.001) risk reduction (P for trend=0.005).
  
  
  CONCLUSIONS
  Combined assessment of factors associated with reverse remodeling can be used for improved selection of patients for cardiac resynchronization therapy. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.
authors: Heart Research Follow-Up Program, Box 653, Cardiology Division, University of Rochester Medical Center, Rochester, NY 14642, USA. Ilan.Goldenberg@heart.rochester.edu
authors: Ilan
authors: I
authors: Goldenberg
authors: Arthur J
authors: AJ
authors: Moss
authors: W Jackson
authors: WJ
authors: Hall
authors: Elyse
authors: E
authors: Foster
authors: Jeffrey J
authors: JJ
authors: Goldberger
authors: Peter
authors: P
authors: Santucci
authors: Timothy
authors: T
authors: Shinn
authors: Scott
authors: S
authors: Solomon
authors: Jonathan S
authors: JS
authors: Steinberg
authors: David
authors: D
authors: Wilber
authors: Alon
authors: A
authors: Barsheshet
authors: Scott
authors: S
authors: McNitt
authors: Wojciech
authors: W
authors: Zareba
authors: Helmut
authors: H
authors: Klein
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012306:Risk; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016896:Treatment Outcome; D014463:Ultrasonography; D020257:Ventricular Remodeling