title: PAI-1 and t-PA/PAI-1 complex potential markers of fibrinolytic bleeding after cardiac surgery employing cardiopulmonary bypass.
abstract: BACKGROUND
  Enhanced bleeding remains a serious problem after cardiac surgery, and fibrinolysis is often involved. We speculate that lower plasma concentrations of plasminogen activator inhibitor - 1 (PAI-1) preoperatively and tissue plasminogen activator/PAI-1 (t-PA/PAI-1) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding.
  
  
  METHODS
  Totally 88 adult patients (mean age 66 ± 10 years) scheduled for cardiac surgery, were enrolled into a prospective study. Blood samples were collected pre-operatively, on admission to the recovery and at 6 and 24 hours postoperatively. Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study. The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage (CTD): Group I > 500ml, Group II ≤ 500ml. Associations between CTD, PAI-1, t-PA/PAI-1 complex and D-dimer were analyzed with SPSS.
  
  
  RESULTS
  Nine patients were excluded because of surgical bleeding. Of the 79 remaining patients, 38 were allocated to Group I and 41 to Group II. The CTD volumes correlated with the preoperative plasma levels of PAI-1 (r = - 0.3, P = 0.009). Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups (P < 0.001 and P = 0.012, respectively). Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively.
  
  
  CONCLUSIONS
  Lower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery.
authors.affiliation: Department of Anaesthesiology and Cardiac surgery, Pauls Stradins Clinical University Hospital, Pilsonu street 13, Riga, Latvia. agnese_krauze@yahoo.com.
authors.forename: Agnese
authors.initials: A
authors.lastname: Ozolina
authors.forename: Eva
authors.initials: E
authors.lastname: Strike
authors.forename: Inta
authors.initials: I
authors.lastname: Jaunalksne
authors.forename: Angelika
authors.initials: A
authors.lastname: Krumina
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Bjertnaes
authors.forename: Indulis
authors.initials: I
authors.lastname: Vanags