title: An anterior left ventricular lead position is associated with increased mortality and non-response in cardiac resynchronization therapy.
abstract: BACKGROUND
  Non-response to cardiac resynchronization therapy (CRT) might be due to insufficient resynchronization as a result of a sub-optimal left ventricular lead positon (LV-LP).
  
  
  OBJECTIVE
  To evaluate the impact of different LV-LPs on mortality and symptomatic improvement in a large cohort of patients treated with CRT.
  
  
  METHODS
  We performed a nationwide cohort study on consecutive patients receiving a CRT device from 1997 to 2012 registered in the Danish pacemaker and ICD register. The LV-LP was defined clockwise in a left anterior oblique (LAO) view and categorized as anterior (≤2 o'clock), lateral (2 to 4 o'clock) or posterior (>4 o'clock), and as basal, mid-ventricular, or apical in a right anterior oblique (RAO) view. Outcomes were all cause mortality and clinical response (improvement in NYHA class). Adjusted hazard ratio (aHR) and odds ratio (aOR) with 95% confidence intervals (CI) were calculated using Cox and logistic regression analysis.
  
  
  RESULTS
  A total of 2594 patients were included. A lateral LV-LP, (aHR 0.77, 95% CI 0.64-0.92, p=0.004), and a posterior LV-LP, (aHR 0.71 95% CI 0.53-0.97, p=0.029) were associated with lower mortality as compared to an anterior LV-LP. A lateral LV-PV was associated with higher clinical response rate as compared to an anterior LV-LP (aOR 1.37, 1.03-1.83, p=0.032). No statistically significant associations were observed between LV-LP in the RAO view and mortality or clinical response.
  
  
  CONCLUSIONS
  An anterior left ventricular lead position is associated with increased all-cause mortality and lower clinical response rate in patients treated with CRT and should be avoided.
authors: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: Mads.Brix.Kronborg@ki.au.dk.
authors: Mads Brix
authors: MB
authors: Kronborg
authors: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors: Jens Brock
authors: JB
authors: Johansen
authors: Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.
authors: Sam
authors: S
authors: Riahi
authors: Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors: Helen Hoegh
authors: HH
authors: Petersen
authors: Department of Cardiology, Gentofte Hospital, Copenhagen University Hospital, Copenhagen, Denmark.
authors: Jens
authors: J
authors: Haarbo
authors: Department of Heart, Lung and Vascular Surgery, Odense University Hospital, Odense, Denmark.
authors: Ole Dan
authors: OD
authors: Jørgensen
authors: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
authors: Jens Cosedis
authors: JC
authors: Nielsen
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods; D058409:Cardiac Resynchronization Therapy Devices / Q000009:adverse effects*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D004452:Echocardiography / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods / Q000592:standards; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Biventricular pacing; Cardiac resynchronization therapy; Heart failure; Lead position; Pacing