title: Left ventricular lead position and outcomes in the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT).
abstract: BACKGROUND
  Conflicting data exist regarding the association between left ventricular (LV) lead position and benefit from cardiac resynchronization therapy. We evaluated the relationships between LV lead positions and the risk of death or hospitalization for heart failure (HF) in the cardiac resynchronization therapy arm of the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT).
  
  
  METHODS
  LV lead position was categorized by site investigator (MD) and in a chest radiograph core laboratory (CXR) as "anterior," "lateral," or "posterior" in the short axis, and "basal," "mid," or "apical" in the long axis. Agreement between MD and CXR LV lead position classification was evaluated and the independent relationship between LV lead position and clinical outcome was assessed using Cox multivariable models.
  
  
  RESULTS
  Agreement between MD and CXR LV lead position was poor (κ ≤ 0.26). Over 39 ± 20 months, 140 of 447 (31.3%) patients met the RAFT primary end point (death or HF hospitalization). In adjusted analyses, neither MD-determined nor CXR-determined anterior or apical LV lead position was significantly associated with the primary outcome. However, CXR-defined apical LV lead position was associated with a higher risk of HF hospitalization (hazard ratio, 1.99; P = 0.004).
  
  
  CONCLUSIONS
  Poor agreement between implanting physician and core lab CXR-based categorizations of LV lead position was observed. Neither categorization method resulted in significant associations between apical or anterior LV lead position and the risk of the composite primary outcome of death or heart failure hospitalization. However, CXR-defined apical lead position was associated with increased risk of HF hospitalization.
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada. Electronic address: sbwilton@ucalgary.ca.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilton
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Derek V
authors.initials: DV
authors.lastname: Exner
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Healey
authors.affiliation: University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Birnie
authors.affiliation: London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada.
authors.forename: Malcolm O
authors.initials: MO
authors.lastname: Arnold
authors.affiliation: QEII Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: John L
authors.initials: JL
authors.lastname: Sapp
authors.affiliation: Montreal Heart Institute, Montreal, Quebec, Canada.
authors.forename: Bernard
authors.initials: B
authors.lastname: Thibault
authors.affiliation: Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Simpson
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Stanley
authors.initials: S
authors.lastname: Tung
authors.affiliation: Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Eugene
authors.initials: E
authors.lastname: Crystal
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Soori
authors.initials: S
authors.lastname: Sivakumaran
authors.affiliation: Southlake Regional Health Centre, Newmarket, Ontario, Canada.
authors.forename: Yaariv
authors.initials: Y
authors.lastname: Khaykin
authors.affiliation: University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Yetisir
authors.affiliation: University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
authors.forename: George
authors.initials: G
authors.lastname: Wells
authors.affiliation: University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
authors.forename: Anthony S L
authors.initials: AS
authors.lastname: Tang
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D009202:Cardiomyopathies / Q000453:epidemiology; D017147:Defibrillators, Implantable; D004567:Electrodes, Implanted; D005260:Female; D006333:Heart Failure / Q000453:epidemiology / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D063868:Patient Outcome Assessment; D016016:Proportional Hazards Models; D011859:Radiography