Local and systemic application of tranexamic acid in heart valve surgery: a prospective, randomized, double blind LOST study.

The study was performed to examine a possible augmentation of systemic administration of tranexamic acid by the additional topical application during heart valve surgery in the post-aprotinin era. One-hundred patients were enrolled in the study and all the patients were given tranexamic acid intravenously. The participants were randomized into two groups (A, n = 49; B, n = 51), and before commencing the sternal suturing, the study solution (group A: 250 ml of normal saline + tranexamic acid 2.5 g, placebo group B: 250 ml of normal saline) was poured into the pericardial cavity. The cumulative blood loss (geometric means [95% confidence intervals]) 4 h after the surgery was 86.1 [56.1, 132.2] ml in group A, and 135.4 [94.3, 194.4] in group B, test for equality of geometric means P = 0.107, test for equality of variances P = 0.059. Eight hours after the surgery, the blood loss was 199.4 [153.4, 259.2] ml in group A, 261.7 [205.1, 334.0] ml in group B, P = 0.130 and P = 0.050, respectively. Twenty-four hours postoperatively the blood loss was 504.2 [436.0, 583.0] ml in group A, 569.7 [476.0, 681.7] ml in group B, P = 0.293 and P = 0.014, respectively. The proportion of patients transfused postoperatively by fresh frozen plasma differed significantly between the two study groups (group A: n = 21, group B: n = 36, P = 0.008). Our hypothesis is supported by a significant difference in the inter-group variance of blood loss and the proportion of patients requiring fresh frozen plasma; however evident differences in mean postoperative blood loss were not statistically significant.

Postoperative blood loss in coronary surgery. No real impact of fibrinolysis detected by thromboelastography and D-dimers. A prospective, randomized study.

Although in many cardiac surgery centers pharmacological strategies based on fibrinolytic inhibitors are used on a routine basis, detailed knowledge of fibrinolysis during various settings of coronary surgery is still limited. Sixty-five patients scheduled for coronary surgery were randomized into 3 groups: group A--conventional coronary artery bypass grafting, group B--off-pump surgery, and group C--coronary artery bypass grafting with modified, rheoparin coated cardiopulmonary bypass with the avoidance of reinfusion of cardiotomy blood into the circuit. The sampling time points for rotation thromboelastographic evaluations were as follows: preoperatively, 15 minutes after sternotomy, on the completion of peripheral bypass anastomoses, at the end of the procedures, and 24 hours after the end of surgery. D-dimer levels were evaluated before surgery, at the end of procedures, and 24 hours after surgery. Thromboelastographic signs of fibrinolysis (evaluated by Lysis Onset Time-intergroup differences at 60 and 150 minutes of assessment: P = 0.003 and P < 0.001, respectively) were clearly detectable during cardiopulmonary bypass in group A, but not at any time in groups B and C. At the other sampling times all thromboelastographic parameters were similar in all groups. In group A, no exceptional bleeding tendency (during 24 hours), as compared to groups B and C (geometric means and 95% confidence intervals: group A: 686.7 [570.8; 826.1] mL, group B: 555.3 [441.3; 698.9] mL, group C: 775.6 [645.1; 932.3] mL, P = 0.157), and no significant correlations between Lysis Onset Time, postoperative blood loss, and D-dimer levels were found. No significant differences in postoperative blood loss related to cardiac surgeons and assistant surgeons were detected. Thromboelastographic signs of increased fibrinolysis were detectable in the important proportion of coronary surgery patients operated on with the use of conventional cardio-pulmonary bypass, but not in off-pump patients and those operated on with the biocompatible surface-modified circuit without reinfusion of cardiotomy suction blood. These signs resolved spontaneously at the end of surgery and were not associated with increased postoperative bleeding. No significant correlation with D-dimer levels was found.

Fibrinolysis in coronary artery surgery: detection by thromboelastography.

Sixty-five patients scheduled for coronary surgery were randomized into three groups: A - conventional coronary artery bypass grafting, B - off-pump surgery, C - coronary artery bypass grafting with modified, rheoparin coated cardiopulmonary bypass with the avoidance of re-infusion of cardiotomy blood into the circuit. On the completion of peripheral bypass anastomoses, highly significant inter-group differences were found in the thromboelastographic parameter lysis of set time at 60 min of assessment (P=0.003) and at 150 min of assessment (P<0.001), the mean values of these parameters were significantly lower in group A as compared with both groups B and C, which were statistically indistinguishable. Lysis on set time on the completion of peripheral bypass anastomoses <50% was detected in 12 patients (52.2%) originating from group A. At the other sampling times (preoperatively, 15 min after sternotomy, at the end of the procedures, and 24 h later) thromboelastographic parameters were similar in all groups. In group A no significant correlations between lysis on set time, postoperative blood loss and D-dimer levels were found. Based on our results, thromboelastographic signs of fibrinolysis were clearly detectable during cardiopulmonary bypass in group A, but not at any time in groups B and C.

Off-pump versus on-pump coronary artery surgery.

The aim of this preliminary, prospective, randomized study was to compare rotation thromboelastography (roTEG) results and D-dimer levels in off-pump versus on-pump coronary surgery in order to identify the activation of fibrinolysis. Twenty patients scheduled for coronary bypass grafting were assessed (off-pump group A, n = 10; on-pump group B, n = 10). Blood samples for roTEG examination were taken preoperatively (t0), 15 minutes after sternotomy (t1), on the completion of peripheral bypass anastomoses (t2), and at the end of procedures (t3). The time points for D-dimer levels analyses were before operation, at the end of procedures, and 24 hours later. A certain degree of roTEG signs of fibrinolysis was noticed at time t2 in both groups and in group B these marks were quite widely, but not significantly expressed (P for intergroup differences for Lysis on Set Time at 60 and 150 minutes were P = 0.190 and P = 0.122, respectively), borderline differences were found for Maximum Clot Firmness (P = 0.082) with a lower mean value for group B (arithmetic means [95% confidence intervals]--57.7 [54.2; 61.2] mm). Completely expressed roTEG signs of hyperfibrinolysis were observed in 2 patients from group B. In group B also the highest geometric means of D-dimers (1326.0 [943.5; 1863.6] ng mL(-1)) and thus a dramatic intergroup difference (P < 0.001) were observed at the end of surgery; 24 hours later the significantly elevated D-dimer levels in both groups (A: 1070.0 [723.5; 1582.6] versus B: 1093.3 [732.0; 1632.9] ng mL(-1)) were equalized (P = 0.932). Our roTEG results display a slightly greater, but fairly subtle activation of fibrinolysis during the course of cardiopulmonary bypass, compared to off-pump cardiac surgery.