PAI-1 and t-PA/PAI-1 Complex Potential Markers of Fibrinolytic Bleeding After Cardiac Surgery Employing Cardiopulmonary Bypass

Agnese Ozolina; Eva Strike; Inta Jaunalksne; Angelika Krumina; Lars J Bjertnaes; Indulis Vanags

Disclosures

BMC Anesthesiol. 2012;12(27) 

In This Article

Results

Clinical Course

Totally 88 consecutive patients (47 men and 41 women) 66 ± 10 years (mean ± SD) of age scheduled for cardiac surgery were considered for inclusion. Eleven patients (12.5%) required reoperation between 10 minutes and 62 hours postoperatively, seven of them within 24 hours because of suspected surgical bleeding or hemipericardium, and they all survived. A surgical bleeding site was identified in nine patients (10.2%) that were discarded from further data analysis. In two patients, a specific site was not found and they were allocated to Group I. As surveyed in Table 1 , 79 patients were subjected to further analysis: 38 patients were diagnosed with a CTD > 500 ml/24h (Group I), whereas 41 patients were registered with a postoperative CTD ≤ 500 ml/24h (Group II). We found significant differences in 24 hour CTD and transfusion requirements between the groups. Moreover, we noticed no significant intergroup differences in demographic characteristics (mean age, gender, BMI, EF, comorbidities, preoperative medication or surgical variables) or in preoperative coagulation tests (PT, APTT, fibrinogen and PLT).

Variables of Fibrinolysis

As shown in Figure 1, both the mean plasma concentration of PAI-1 preoperatively (A) and of t-PA/PAI-1 complex 24 hours postoperatively (B), were lower in Group I (P < 0.001 and P = 0.01, respectively). Postoperatively, mean plasma concentrations of fibrinogen increased less from T1 and beyond in Group I as compared to Group II (P = 0.01) as depicted in Figure 2A. Concomitantly, the mean plasma concentrations of D-dimer were significantly higher (P < 0.05) in Group I as compared to Group II (Figure 2B).

Figure 1.

(A) Preoperative plasma concentration of plasminogen activator inhibitor type-1. (B) Postoperative plasma concentration of tissue plasminogen activator/plasminogen activator inhibitor type-1 complex. Group I, patients with postoperative blood loss of > 500 ml/24 hours; Group II, patients with postoperative blood loss of ≤ 500 ml/24 hours PAI-1, plasminogen activator inhibitor type − 1; t-PA-PAI-1: tissue, plasminogen activator/plasminogen activator inhibitor type-1 complex. Data are presented as mean ± SD.

Figure 2.

(A) Plasma concentrations of fibrinogen: at baseline (TO), upon admision to the intensive care unit (T1), six hours after surgery (T6) and twenty-four hours after surgery (T24). (B) Postoperative plasma concentrations of D-dimer: upon admission to the intensive care unit (T1) six hours after surgery (T6) and twenty-four hours after surgery (T24). Group I, patients with postoperative blood loss of >500 ml/24 hours; Group II, patients with postoperative blood loss of ≤ 500 ml/24 hours. Data presented as mean ± SD.

Associations Between Postoperative Bleeding and Variables of Fibrinolysis

We found no correlation between demographic and surgical parameters and the plasma concentrations of PAI-1 and t-PA/PAI-1 complex. However, preoperative PAI-1 levels correlated inversely with 24 hour postoperative blood loss (Figure 3; r = − 0.3, P = 0.009). In contrast, the correlation between t-PA/PAI-1 complex and 24 hour blood loss did not reach statistical significance (r = − 0.24, P = 0.08).

Figure 3.

Relationships between preoperative plasma concentrations of plasminogen activator inhibitor type - 1 and blood loss over 24 hours of patients subjected to cardiac surgery employing cardiopulmonary bypass. *P < 0.05. PAI-1: plasminogen activator inhibitor type - 1.

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