title: Combined heart-kidney transplant improves post-transplant survival compared with isolated heart transplant in recipients with reduced glomerular filtration rate: Analysis of 593 combined heart-kidney transplants from the United Network Organ Sharing Database.
abstract: OBJECTIVE
  Criteria for simultaneous heart-kidney transplant (HKTx) recipients are unclear. We characterized the evolution of combined HKTx in the United States over time compared with isolated heart transplantation (HTx) and determined factors maximizing post-transplant survival. We focused on whether a threshold estimated glomerular filtration rate (eGFR) could be identified that justified combined transplantation.
  
  
  METHODS
  A supplemented United Network Organ Sharing Dataset identified HTx and HKTx recipients from 2000 to 2010. eGFR was calculated for HTx and recipients were grouped into eGFR quintiles. Time-related mortality was compared among recipients, with multivariable factors sought using Cox proportional hazard regression models.
  
  
  RESULTS
  We identified 26,183 HTx recipients, of whom 593 were HKTx recipients. HTx increased modestly over time (3.6%), whereas prevalence of HKTx increased dramatically (147%). Risk-unadjusted survival was similar among HTx recipients (8.4 ± 0.04 years) and HKTx recipients (7.7 ± 0.2 years) (P = .76). Isolated HTx recipients in the lowest eGFR quintile had decreased survival (P < .001), but those in the third eGFR quintile had superior survival, suggesting a benefit in this subgroup. HTx recipients in the lowest eGFR quintile (eGFR less than mean 37 mL/minute) had worse survival than combined HKTx recipients (7.1 ± 0.07 vs 7.7 ± 0.2; P < .001). Multivariable factors for increased mortality among HTx recipients included lower eGFR, higher recent panel reactive antibody score, older age, African American race, diabetes, longer ischemic time, and certain diagnoses.
  
  
  CONCLUSIONS
  Performance of combined HKTx is increasing out of proportion to isolated HTx. eGFR is an important determinant of improved HTx survival. Combined HKTx recovers post-transplant survival in patients with eGFR <37 mL/minute and can be recommended in this subgroup.
authors.affiliation: Division of Pediatric Cardiothoracic Surgery, Benioff Children's Hospital, University of California, San Francisco, San Francisco, Calif. Electronic address: tara.karamlou@ucsfmedctr.org.
authors.forename: Tara
authors.initials: T
authors.lastname: Karamlou
authors.affiliation: Congenital Cardiac Center, Department of Pediatric Cardiac Surgery, Seattle Children's Hospital, Seattle, Wash.
authors.forename: Karl F
authors.initials: KF
authors.lastname: Welke
authors.affiliation: Congenital Cardiac Center, Department of Pediatric Cardiac Surgery, Seattle Children's Hospital, Seattle, Wash.
authors.forename: D Michael
authors.initials: DM
authors.lastname: McMullan
authors.affiliation: Division of Pediatric Cardiothoracic Surgery, Benioff Children's Hospital, University of California, San Francisco, San Francisco, Calif.
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Cohen
authors.affiliation: Division of Cardiovascular Medicine, Oregon Health & Science University, Portland, Ore.
authors.forename: Jill
authors.initials: J
authors.lastname: Gelow
authors.affiliation: Division of Cardiothoracic Surgery, Oregon Health & Science University, Portland, Ore.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Tibayan
authors.affiliation: Division of Cardiovascular Medicine, Oregon Health & Science University, Portland, Ore.
authors.forename: James M
authors.initials: JM
authors.lastname: Mudd
authors.affiliation: Division of Cardiothoracic Surgery, Oregon Health & Science University, Portland, Ore.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Slater
authors.affiliation: Division of Cardiothoracic Surgery, Oregon Health & Science University, Portland, Ore.
authors.forename: Howard K
authors.initials: HK
authors.lastname: Song
mesh_terms: D059347:Cardio-Renal Syndrome / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D016009:Chi-Square Distribution; D016208:Databases, Factual; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D016027:Heart Transplantation / Q000009:adverse effects / Q000401:mortality; D006801:Humans; D007668:Kidney / Q000503:physiopathology / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000401:mortality; D015999:Multivariate Analysis; D018579:Patient Selection; D016016:Proportional Hazards Models; D020127:Recovery of Function; D051437:Renal Insufficiency / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D009927:Tissue and Organ Procurement; D016896:Treatment Outcome; D014481:United States
keywords: 34; HKTx; HTx; LVAD; UNOS; United Network for Organ Sharing; combined heart-kidney transplant; eGFR; estimated glomerular filtration rate; heart transplant; left ventricular assist device