title: Relative Wall Thickness and the Risk for Ventricular Tachyarrhythmias in Patients With Left Ventricular Dysfunction.
abstract: BACKGROUND
  Relative wall thickness (RWT), defined as 2 times posterior wall thickness divided by the left ventricular (LV) diastolic diameter, is a measure of LV geometry and may be a marker for adverse events in patients with LV dysfunction.
  
  
  OBJECTIVE
  The aim of this study was to investigate the relationship between RWT and the risk for ventricular tachyarrhythmia (VA) in patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy) study.
  
  
  METHODS
  The study population comprised 1,260 patients with mild heart failure and left bundle branch block.
  
  
  RESULTS
  In a multivariable model, RWT was the most powerful echocardiographic measure for estimating the risk of VAs compared with commonly used echocardiographic variables. Patients with low RWT (<0.24) had 83% (p < 0.001) increased risk for VA and 68% (p < 0.001) increase in VA risk or death (VA/death) compared with patients with higher RWT values. Each 0.01-unit decrease in RWT was associated with 12% (p < 0.001) and 10% (p < 0.001) increases in the risk of VA and VA/death, respectively. Treatment with cardiac resynchronization therapy with defibrillator (CRT-D; CRT with implantable cardioverter-defibrillator) was associated with a greater increase in RWT compared with implantable cardioverter-defibrillator at 12 months (4.6 ± 6.8% vs. 1.5 ± 2.7%; p < 0.001), and every 10% increase in RWT in CRT-D patients was associated with 34% (p = 0.027) and 36% (p = 0.009) reductions in the risk of subsequent VA and VA/death, respectively.
  
  
  CONCLUSIONS
  In patients with mild heart failure and left bundle branch block, decreased RWT was associated with an increase in the risk of VA and VA/death. CRT-D therapy was associated with a favorable increase in RWT and reduction in risk of VA and VA/death. (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy [MADIT-CRT]; NCT00180271).
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York; Heart Institute, Sheba Medical Center, Ramat Gan, and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: yitschak.biton@heart.rochester.edu.
authors.forename: Yitschak
authors.initials: Y
authors.lastname: Biton
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York; Heart Institute, Sheba Medical Center, Ramat Gan, and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Valentina
authors.initials: V
authors.lastname: Kutyifa
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Jayson R
authors.initials: JR
authors.lastname: Baman
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Scott
authors.initials: S
authors.lastname: Solomon
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Barbara
authors.initials: B
authors.lastname: Szepietowska
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Bronislava
authors.initials: B
authors.lastname: Polonsky
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.affiliation: Heart Research Follow-up Program, Division of Cardiology, Department of Medicine at the University of Rochester Medical Center, Rochester, New York; Cardiology Department, Rabin Medical Center, Petah Tiqva, and Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel.
authors.forename: Alon
authors.initials: A
authors.lastname: Barsheshet
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004452:Echocardiography / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D017063:Outcome Assessment, Health Care; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013223:Statistics as Topic; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology
keywords: cardiac resynchronization therapy; heart failure; implantable cardioverter-defibrillator; mortality; ventricular fibrillation; ventricular tachycardia