VTE Risk (Patients With History)
There is a paucity of randomized clinical trials on the risk of adverse effects of IV, topical, and oral TXA in patients with known history of a VTE, MI, CVA, TIA, and/or vascular stent placement. The existing high quality literature regarding administration of TXA in patients of generally higher comorbidity burden does not suggest increased risk of adverse thromboembolic events during the perioperative episode of a primary TJA.
Tranexamic Acid in Total Joint Arthroplasty
Developed by the American Association of Hip and Knee Surgeons

Rationale
Despite an established proposed mechanism of action for TXA as a fibrin clot stabilizer, clinician concerns remain over the use of any antifibrinolytic medication in patients considered at “high-risk” for thromboembolic events (e.g., previous history of VTE, MI with vascular stents, cerebral vascular occlusive disease) which continues to limit the widespread adoption of TXA use in hip and knee arthroplasty.13 Since no clinical trials have investigated specific risk factors, the American Society of Anesthesiologists (ASA) physical status classification system was used as a proxy to identify “high-risk” patients among the literature available. In a meta-regression analysis comparing a population of patients with greater than 50% ASA status ≥3 to another population with patients of greater than 50% ASA status 1 or 2, the results demonstrated no increase in the risk of VTE for patients undergoing a primary hip or knee arthroplasty.12 Due to the absence of experimental evidence, we also reviewed observational studies on the topic of TXA administration in patients with specific risk factors. Large database studies suggest TXA administration in patients with a history of VTE or ASA status of ≥ 3 does not experience an increased risk of VTE.14-17

In the “high-risk” patient population, we must consider the summation of the benefits and potential risks of administering TXA. Despite limited data on the safety of TXA, we wish to highlight a parallel lack of evidence for harm. Additionally, evidence has demonstrated that postoperative cardiovascular complications are associated with anemia and high blood transfusion rates.18-20 Therefore we wish to highlight the overall positive summation of data on TXA efficacy in the context of limited evidence for added risk with the use of TXA. In sum, the calculation of the number needed to harm for VTE among the total joint population was 983 patients, but the number needed to treated with IV TXA in THA and TKA to prevent a transfusion was only 4 and 3 patients, respectively.12 Although the available data limits for stronger advocacy and more widespread use in those at “high-risk”, each patient with known risks factors should be considered individually and we advocate for a multidisciplinary approach when deciding whether to withhold or administer TXA.