title: Lack of donor and recipient age interaction in cardiac transplantation.
abstract: BACKGROUND
  The proportion of older donors and recipients is constantly rising in heart transplantation (HTX). The impact of age on different outcomes after HTX has been studied; however, effects of interaction between donor and recipient age remain elusive.
  
  
  METHODS
  This retrospective cohort study comprised 1,190 patients who underwent HTX between 1984 and 2011 at the Medical University Vienna. Multivariable models consisted of a basic set that included donor age, recipient age, and transplant eras and were adjusted for 2 sets of 6 possible confounders and 3 mediator variables. Cox models were used to estimate the risk of death. To search for age-related effects on the development of cardiac allograft vasculopathy (CAV), we applied cause-specific Cox models and proportional sub-distribution hazard models for competing risk data.
  
  
  RESULTS
  Survival was 80%, 77%, 69%, and 56% after 1, 2, 5, and 10 years, respectively. Donor age (hazard ratio [HR], 1.1; 95% confidence interval [CI], 1.0-1.2), recipient age (HR, 1.1; 95% CI, 1.0-1.2), admission from intensive care unit to HTX (HR, 1.5; 95% CI, 1.2-1.9), and diabetes (HR, 1.4; 95% CI, 1.1-1.7) were identified as significant independent risk factors for death. Significant risk factors for CAV were donor age (HR, 1.4; 95% CI, 1.3-1.5) and male recipient sex (HR, 1.5; 95% CI, 1.0-2.2). Recipient age was inversely associated with initiation of CAV (HR, 0.8; 95% CI, 0.8-1.0). Analysis of the interaction between donor and recipient age was not significant for death (p = 0.8) or CAV (p = 0.6).
  
  
  CONCLUSIONS
  We found no interaction between donor and recipient age negatively affecting mortality and CAV. The identified independent risk factors may have implications for allocation strategies in elderly recipients.
authors.affiliation: Department of Cardiac Surgery.
authors.forename: Farsad Alexander
authors.initials: FA
authors.lastname: Eskandary
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems.
authors.forename: Maria
authors.initials: M
authors.lastname: Kohl
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems.
authors.forename: Daniela
authors.initials: D
authors.lastname: Dunkler
authors.affiliation: Department of Cardiac Surgery.
authors.forename: Arezu
authors.initials: A
authors.lastname: Aliabadi
authors.affiliation: Department of Cardiac Surgery.
authors.forename: Martina
authors.initials: M
authors.lastname: Grömmer
authors.affiliation: Department of Cardiothoracic and Vascular Anaesthesia, Medical University Vienna, Vienna, Austria.
authors.forename: Arno
authors.initials: A
authors.lastname: Schiferer
authors.affiliation: Department of Cardiac Surgery.
authors.forename: Johannes
authors.initials: J
authors.lastname: Gökler
authors.affiliation: Department of Adult Cardiothoracic Surgery, University of California, San Francisco, San Francisco, California.
authors.forename: Georg
authors.initials: G
authors.lastname: Wieselthaler
authors.affiliation: Department of Cardiac Surgery.
authors.forename: Günther
authors.initials: G
authors.lastname: Laufer
authors.affiliation: Department of Cardiac Surgery. Electronic address: andreas.zuckermann@meduniwien.ac.at.
authors.forename: Andreas
authors.initials: A
authors.lastname: Zuckermann
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D009202:Cardiomyopathies / Q000209:etiology / Q000401:mortality* / Q000601:surgery*; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate; D014019:Tissue Donors; D066027:Transplant Recipients; D055815:Young Adult
keywords: age interaction; competing risk model; donor age; heart transplantation; outcomes; recipient age