title: Heart surgery with extracorporeal circulation leads to platelet activation at the time of hospital discharge.
abstract: OBJECTIVE
  Heart surgery with extracorporeal circulation has a marked effect on platelet function and coagulation accounting for abnormal blood loss and allegedly a low incidence of thromboembolic complications. Little is known about platelet function at the time of hospital discharge of routine patients.
  
  
  METHODS
  Blood samples from 91 patients undergoing elective heart surgery were drawn before surgery and prior to discharge. Thirty-seven patients underwent coronary artery surgery and 54 an aortic valve implantation. The mean age of patients was 69+/-9 years. Fifty patients were male and 41 female. Platelet function was evaluated using plasma beta-thromboglobulin quantification in enzyme-linked immunosorbent assay. In addition, flow cytometric analysis of platelet-monocyte conjugates and platelet-neutrophil conjugates was performed.
  
  
  RESULTS
  The platelet count before discharge was significantly increased (265+/-86 vs. 212+/-61 x 10(9)/l preoperatively). beta-Thromboglobulin was significantly increased (176+/-127 vs. 79+/-70 ng/ml preoperatively) and flow cytometry proved a significant increase in monocyte-platelet aggregates (8.3+/-5.4% vs. 5.3+/-2.6% preoperatively) indicating platelet activation at the time of hospital discharge. There were no significant differences among the three subgroups coronary surgery, mechanical valve insertion and biological valve insertion.
  
  
  CONCLUSIONS
  Heart surgery with extracorporeal circulation leads to significant platelet activation and a reactive increase in platelet count before discharge. This is in contrast to the reduced platelet function immediately postoperatively.
authors.affiliation: St. Elisabeth Heart Centre, Norwegian University of Science and Technology, 7018, Trondheim, Norway. alexander.wahba@rit.no
authors.forename: Alexander
authors.initials: A
authors.lastname: Wahba
authors.forename: Vibeke
authors.initials: V
authors.lastname: Videm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002315:Cardiopulmonary Bypass; D003327:Coronary Disease / Q000097:blood* / Q000601:surgery*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D015539:Platelet Activation; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013927:Thrombosis / Q000209:etiology*