title: Institutional volume of heart transplantation with left ventricular assist device explantation influences graft survival.
abstract: BACKGROUND
  There are increasing numbers of patients undergoing orthotopic heart transplantation (OHT) with left ventricular assist device (LVAD) explantation (LVAD explant-OHT). We hypothesized that LVAD explant-OHT is a more challenging surgical procedure compared to OHT without LVAD explantation and that institutional LVAD explant-OHT procedural volume would be associated with post-transplant graft survival. We sought to assess the impact of institutional volume of LVAD explant-OHT on post-transplant graft survival.
  
  
  METHODS
  This is a retrospective analysis of the Scientific Registry of Transplant Recipients for adult OHTs with long-term LVAD explantation. LVAD explant-OHT volume was characterized on the basis of the center's year-specific total OHT volume (OHTvol) and year-specific LVAD explant-OHT volume quartile (LVADvolQ). The effect of LVADvolQ on graft survival (death or re-transplantation) was analyzed.
  
  
  RESULTS
  From 2004 to 2011, 2,681 patients underwent OHT with LVAD explantation (740 with HeartMate XVE, 1,877 with HeartMate II and 64 with HeartWare devices). LVAD explant-OHT at centers falling in the lowest LVADvolQ was associated with reduced post-transplant graft survival (p = 0.022). After adjusting for annualized OHTvol (HR = 0.998, 95% CI 0.993 to 1.003, p = 0.515 and pulsatile XVE (HR = 0.842, 95% CI 0.688 to 1.032, p = 0.098), multivariate analysis confirmed a significantly (approximately 37%) increased risk of post-transplant graft failure among explant-OHT procedures occurring at centers in the lowest volume quartile (HR = 1.371, 95% CI 1.030 to 1.825, p = 0.030).
  
  
  CONCLUSIONS
  Graft survival is decreased when performed at centers falling in the lowest quartile of LVAD explant-OHT for a given year. This volume-survival relationship should be considered in the context of limited donor organ availability and the rapidly growing number of LVAD centers.
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Haglund
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville Tennessee; Department of Biostatistics, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Irene D
authors.initials: ID
authors.lastname: Feurer
authors.affiliation: Division of Cardiovascular Surgery, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Rashid M
authors.initials: RM
authors.lastname: Ahmad
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: DiSalvo
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Lenihan
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Keebler
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Kelly H
authors.initials: KH
authors.lastname: Schlendorf
authors.affiliation: Division of Cardiovascular Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: John M
authors.initials: JM
authors.lastname: Stulak
authors.affiliation: Division of Cardiology, Vanderbilt University Medical Center, Nashville Tennessee.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wigger
authors.affiliation: Division of Cardiovascular Surgery, Vanderbilt University Medical Center, Nashville Tennessee. Electronic address: simon.maltais@vanderbilt.edu.
authors.forename: Simon
authors.initials: S
authors.lastname: Maltais
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020878:Device Removal; D005260:Female; D006084:Graft Rejection / Q000453:epidemiology; D006085:Graft Survival; D006333:Heart Failure / Q000401:mortality / Q000601:surgery*; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D061846:Hospitals, Low-Volume / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000401:mortality / Q000601:surgery*; D055815:Young Adult
keywords: heart transplantation; left ventricular assist device; transplant center volume