Fibrinolytic inhibitors in off-pump coronary surgery: a prospective, randomized, double-blind TAP study (tranexamic acid, aprotinin, placebo).

OBJECTIVE: To evaluate and compare hemostatic effects of tranexamic acid vs. aprotinin vs. placebo in off-pump coronary artery bypass (OPCAB) surgery and, in addition, to assess the safety of fibrinolytic inhibitors therapies.

METHODS: In a prospective, randomized, double-blind study finally 91 patients undergoing OPCAB were investigated (group A, n=32, tranexamic acid 1g before skin incision and continuously 200mg/h; group B, n=29, aprotinin 1,000,000IU before skin incision and 250,000IU/h; group C, n=30, placebo).

RESULTS: Highly significant inter-group differences were found in cumulative blood loss within 4h (geometric means [95% confidence intervals]-group A: 89.3 [72.7, 109.8] mL, group B: 72.3 [49.2, 106.3] mL and group C: 192.3 [151.8, 243.5] mL) (P<0.001), within 8h (group A: 152.1 [120.7, 191.6] mL, group B: 130.3 [88.1, 192.8] mL and group C: 283.8 [226.0, 356.3] mL) (P=0.001), and within 24h postoperatively (group A: 410.3 [337.6, 498.6] mL, group B: 345.8 [256.0, 398.2] mL and group C: 619.8 [524.3, 732.8] mL) (P<0.001). At all time points, placebo group C was significantly distinct from the groups treated with fibrinolytic inhibitors (groups A and B). However, no differences between groups A and B were found. Both mean hemoglobin and hematocrit values 24h postoperatively were different between the groups (P=0.018 and P=0.077, respectively), acheiving the lowest value in group C. Number of re-transfuzed patients was highest in group C, but without statistical significance (either packed red blood cells, P=0.119 or fresh-frozen plasma, P=0.118). We observed one postoperative myocardial infarction in aprotinin treated group B and one temporary postoperative myocardial ischemia in placebo group C, no cerebrovascular or pulmonary embolism was noticed. Treated groups A and B did not demonstrate postoperative increase in mean levels of myocardial enzymes, compared with group C. Significantly higher mean values of D-dimer were found in group C 24h postoperatively (P<0.001).

CONCLUSIONS: Both tranexamic acid and aprotinin seem to be similarly effective in the reduction of postoperative blood loss in OPCAB. Tranexamic acid appears to be cost-effective and safe alternative to aprotinin.