title: Impact of ABO-incompatible listing on wait-list outcomes among infants listed for heart transplantation in the United States: a propensity analysis.
abstract: BACKGROUND
  The purported advantage of ABO-incompatible (ABO-I) listing is to reduce wait times and wait-list mortality among infants awaiting heart transplantation. We sought to describe recent trends in ABO-I listing for US infants and to determine the impact of ABO-I listing on wait times and wait-list mortality.
  
  
  RESULTS
  In this multicenter retrospective cohort study using Organ Procurement and Transplant Network data, infants<12 months of age listed for heart transplantation between 1999 and 2008 (n=1331) were analyzed. Infants listed for an ABO-I transplant were compared with a propensity score-matched cohort listed for an ABO-compatible transplant through the use of a Cox shared-frailty model. The primary end point was time to heart transplantation. The percentage of eligible infants listed for an ABO-I heart increased from 0% before 2002 to 53% in 2007 (P<0.001 for trend). Compared with infants listed exclusively for an ABO-compatible heart, infants with a primary ABO-I listing strategy (n=235) were more likely to be listed 1A, to have congenital heart disease and renal failure, and to require extracorporeal membrane oxygenation. For the propensity score-matched groups (n=197 matched pairs), there was no difference in wait-list mortality; however, infants with blood type O assigned an ABO-I listing strategy were more likely to undergo heart transplantation by 30 days (31% versus 16%; P=0.007) with a less pronounced effect for infants with other blood types.
  
  
  CONCLUSIONS
  The proportion of US infants listed for an ABO-I heart transplantation has risen dramatically in recent years but still appears to be preferentially used for sicker infant candidates. The ABO-I listing strategy is associated with a higher likelihood of transplantation within 30 days for infants with blood group O and may benefit a broader range of transplantation candidates.
authors.affiliation: Department of Cardiology, Children's Hospital Boston, and Department of Pediatrics, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA. christopher.almond@cardio.chboston.org
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Almond
authors.forename: Kimberlee
authors.initials: K
authors.lastname: Gauvreau
authors.forename: Ravi R
authors.initials: RR
authors.lastname: Thiagarajan
authors.forename: Gary E
authors.initials: GE
authors.lastname: Piercey
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Blume
authors.forename: Leslie B
authors.initials: LB
authors.lastname: Smoot
authors.forename: Francis
authors.initials: F
authors.lastname: Fynn-Thompson
authors.forename: Tajinder P
authors.initials: TP
authors.lastname: Singh
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000276:immunology / Q000401:mortality / Q000601:surgery; D016027:Heart Transplantation / Q000276:immunology* / Q000401:mortality*; D006648:Histocompatibility / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D014019:Tissue Donors / Q000600:supply & distribution; D009927:Tissue and Organ Procurement / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology; D014850:Waiting Lists
chemical_list: D000017:ABO Blood-Group System
references.citation: J Heart Lung Transplant. 1997 Dec;16(12):1255-66
references.pmid: 9436138
references.citation: Transplant Proc. 1987 Dec;19(6):4463-7
references.pmid: 3321601
references.citation: Stat Med. 1998 Oct 15;17(19):2265-81
references.pmid: 9802183
references.citation: J Thorac Cardiovasc Surg. 2006 Feb;131(2):455-61
references.pmid: 16434278
references.citation: J Heart Lung Transplant. 2007 Nov;26(11):1163-9
references.pmid: 18022083
references.citation: J Heart Lung Transplant. 2008 Oct;27(10):1085-9
references.pmid: 18926398
references.citation: J Heart Lung Transplant. 1999 Nov;18(11):1065-70
references.pmid: 10598729
references.citation: Eur J Cardiothorac Surg. 2007 Mar;31(3):339-43; discussion 343
references.pmid: 17239612
references.citation: Circulation. 2009 Feb 10;119(5):717-727
references.pmid: 19171850
references.citation: N Engl J Med. 2001 Mar 15;344(11):793-800
references.pmid: 11248154
references.citation: J Heart Lung Transplant. 2009 Dec;28(12):1292-8
references.pmid: 19782580
references.citation: J Heart Lung Transplant. 2003 Feb;22(2):147-53
references.pmid: 12581762
references.citation: Transplantation. 2004 May 15;77(9):1389-94
references.pmid: 15167596
references.citation: Pediatrics. 1976 Aug;58(2):259-63
references.pmid: 951142
references.citation: Circulation. 2007 Sep 11;116(11 Suppl):I172-8
references.pmid: 17846300
references.citation: Am J Transplant. 2008 Jan;8(1):208-15
references.pmid: 18021280
references.citation: Transpl Int. 2005 Oct;18(10):1210-4
references.pmid: 16162109
references.citation: J Heart Lung Transplant. 2007 Sep;26(9):876-82
references.pmid: 17845925