Impact of tranexamic acid vs. aprotinin on blood loss and transfusion requirements after cardiopulmonary bypass

Introduction: Aprotinin (AP) reduces blood loss and transfusions after cardiopulmonary bypass (CPB), but may sensitize patients and is expensive. Tranexamic acid (TA) has less side effects, but data regarding its efficacy are controversial. The aim of our prospective, randomized, double-blind study was to compare the impact of AP vs. TA on drainage blood loss and transfusion requirements in patients undergoing primary CABG on CPB.

Methods: One hundred twenty adult patients were randomized to receive either high-dose AP according to Hammersmith or a total of 2g TA. Perioperative blood products were transfused in a standardized fashion. Blood loss was measured up to 24 hours. Demographic and clinical patient data were collected until hospital discharge.

Results: The data from 118 patients (TA: n=58, AP: n=60) who completed the study according to protocol were analyzed. Blood loss at 24h postop in TA patients was significantly higher (896±354ml) as compared to AP patients (756±347ml; p=0.03). TA patients received 1.5±1.5 units red blood cells (AP: 1.5±1.7, p=1.0), 1.3±2.0 units fresh frozen plasma (AP: 1.0±2.0, p=0.38), and 0.5±1.4 units platelets (AP: 0.2±0.7, p=0.15). Clinical data including perioperative myocardial infarction rate, acute renal failure, mechanical ventilation, hospital stay, and mortality were not significantly different between both groups.

Conclusion: Our data show a difference in blood loss between TA and high-dose AP. Although statistically significant, it has little clinical relevance, because perioperative transfusion requirements were similar for both groups. Thus, TA appears to be a cost effective alternative to AP in primary CABG patients.