title: Clinical Outcomes of Cardiac Resynchronization with Epicardial Left Ventricular Lead.
abstract: BACKGROUND
  Left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) can be achieved via a transvenous or epicardial route. A surgically implanted epicardial LV (eLV) lead is used after a standard transvenous LV (tLV) lead implantation has failed. However, studies of clinical outcomes in patients with eLV leads and comparisons of outcome between tLV and eLV-CRT are sparse. Therefore, the purpose of this study is to compare clinical response between tLV-CRT and eLV-CRT, as well as to understand the differences within the eLV-CRT population.
  
  
  METHODS
  Forty-four patients received eLV-CRT following unsuccessful attempts of tLV-CRT implantation between 2002 and 2013 at the University of California, San Diego (UCSD) and Mayo Clinics. These patients were matched for age, gender, and etiology of cardiomyopathy in a 1:2 ratio with a cohort of patients who received tLV-CRT during the same time period.
  
  
  RESULTS
  During a mean follow-up of 57 months, similar clinical outcomes and survival rate were noted between tLV and eLV-CRT patients (all P > 0.05). Within the eLV-CRT group, dilated cardiomyopathy patients had significant improvement in New York Heart Association class and ejection fraction (both P < 0.05), while ischemic cardiomyopathy patients did not (both P > 0.05). eLV-CRT patients with nonanterior lead location had significantly improved survival (P < 0.001). There was also a trend for improved survival in those with nonapical lead location (P = 0.09).
  
  
  CONCLUSIONS
  In this case-matched two-centered study, comparable improvements were noted in patients with tLV-CRT and eLV-CRT. Operators should target nonanterior and nonapical locations during eLV-CRT implantation. Use of eLV-CRT should be considered a viable alternative for CRT candidates.
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Diego, California.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Cardiovascular Diseases, Henan Provincial People's Hospital, Zhengzhou University, Henan, China.|Department of Cardiovascular Diseases, Mayo Clinics, Rochester, Minnesota.
authors.forename: Haixia
authors.initials: H
authors.lastname: Fu
authors.affiliation: Department of Surgery, Division of Cardiothoracic Surgery, University of California, San Diego, California.
authors.forename: Victor G
authors.initials: VG
authors.lastname: Pretorius
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinics, Rochester, Minnesota.
authors.forename: Dachun
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Health Science Research, Mayo Clinics, Rochester, Minnesota.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Wiste
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinics, Rochester, Minnesota.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Diego, California.
authors.forename: Gregory K
authors.initials: GK
authors.lastname: Feld
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinics, Rochester, Minnesota.
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Cha
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Diego, California.
authors.forename: Ulrika M
authors.initials: UM
authors.lastname: Birgersdotter-Green
mesh_terms: D017677:Age Distribution; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D058406:Cardiac Resynchronization Therapy / Q000379:methods* / Q000401:mortality*; D009202:Cardiomyopathies / Q000401:mortality* / Q000517:prevention & control*; D015897:Comorbidity; D004566:Electrodes; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D012189:Retrospective Studies; D017678:Sex Distribution; D015996:Survival Rate; D016896:Treatment Outcome
keywords: CHF; epicardial CRT; pacing; surgery