title: Association of ABO-mismatched platelet transfusions with morbidity and mortality in cardiac surgery.
abstract: BACKGROUND
  The transfusion of ABO-mismatched platelets has been associated with increased morbidity and mortality during induction therapy for acute leukemia and allogeneic progenitor cell transplantation.
  
  
  METHODS
  Reported here is a cohort study of 153 patients undergoing primary coronary artery bypass graft or coronary valve replacement surgery by two surgeons in one institution during 1997 and 1998. All statistics employed nonparametric two-sided tests (Mann-Whitney; Fisher's exact test).
  
  
  RESULTS
  Patients receiving at least one ABO-mismatched pool of platelets had a significantly longer hospital stay, more days of fever, greater total hospital charges, and more RBC transfusions. Mortality, hours in the intensive care unit, days on antibiotics, and numbers of platelet transfusions were also greater in recipients of ABO-mismatched platelets, but these differences were of less statistical significance. When the analysis was restricted to the 139 patients who received no more than two pools of platelets, the trends for increased morbidity and mortality (8.6% vs. 1.9%; p = 0.10) in recipients of ABO-mismatched platelets persisted. The number of RBC transfusions required in this latter cohort was 50 percent greater (mean, 6.1 vs. 9.2; p = 0.02), despite the fact that the number of platelet transfusions given was similar (mean, 1.2 vs. 1.3 pools; p = 0.22).
  
  
  CONCLUSIONS
  ABO-mismatched platelet transfusions are associated with unfavorable outcomes in cardiac surgery, a relationship that remains unexplained. As this association has been found in three cohort studies in various clinical settings, further investigation of this association is warranted.
authors.affiliation: Department of Pathology, University of Rochester Medical Center, Rochester, New York 14642, USA. Neil_Blumberg@urmc.rochester.edu
authors.forename: N
authors.initials: N
authors.lastname: Blumberg
authors.forename: J M
authors.initials: JM
authors.lastname: Heal
authors.forename: G L
authors.initials: GL
authors.lastname: Hicks
authors.forename: W H
authors.initials: WH
authors.lastname: Risher
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000368:Aged; D001788:Blood Grouping and Crossmatching; D001026:Coronary Artery Bypass; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion; D011183:Postoperative Complications / Q000401:mortality; D012307:Risk Factors
chemical_list: D000017:ABO Blood-Group System