RESUMO
OBJECTIVE: Tranexamic acid reduces blood loss and transfusion in on-pump coronary artery bypass graft (CABG) surgery. Compared with on-pump, off-pump surgery is associated with less blood loss and transfusion. Therefore, tranexamic acid may be less effective for off-pump surgery, and its safety profile may be different in this setting. The aim of this study was to determine the efficacy and safety of tranexamic acid for off-pump CABG surgery. DESIGN: Systematic review and meta-analysis. SETTING: University of Edinburgh. INTERVENTIONS: The administration of tranexamic acid. METHODS: A systematic review of randomized controlled trials administering tranexamic acid to patients undergoing off-pump CABG surgery. A meta-analysis of 24-hour blood loss, postoperative allogeneic transfusion, and thromboembolic events. MEASUREMENTS AND MAIN RESULTS: Eight trials were identified. The lack of appropriate data limited the meta-analysis on blood loss. Tranexamic acid significantly reduced the overall risk of allogeneic blood component transfusion (risk ratio = 0.47; 95% confidence intervals, 0.33-0.66; p < 0.0001) and packed red blood cell transfusions (risk ratio = 0.51; 95% CI, 0.36-0.71; p = 0.0001). No association was found between tranexamic acid and myocardial infarction, stroke, or pulmonary embolism. Population sizes of meta-analyses ranged from 466 to 544. CONCLUSIONS: Tranexamic acid reduces blood transfusion after off-pump surgery. Although no association with adverse events was found, the population sample size was too small to detect rare but clinically significant adverse events. A well-designed randomized controlled trial with an appropriate sample size is required to confirm tranexamic acid effectiveness and safety in off-pump CABG surgery.
