Preoperative Management of Antithrombotics in Arthroplasty

Brian T. Barlow, MD; Matthew T. Hannon, MD; Jacob E. Waldron, DO

Disclosures

J Am Acad Orthop Surg. 2019;27(23):878-886. 

In This Article

Abstract and Introduction

Abstract

Antithrombotic therapy is common in the arthroplasty patient population; the preoperative management of chronic antithrombotic medications requires coordination among the medical team. It is estimated that approximately 250,000 or 10% of patients on chronic antithrombotic medication undergo treatment interruption for surgical procedures annually in North America. Although the description of postoperative anticoagulation management after arthroplasty is extensive, orthopaedic literature describing the preoperative management of antithrombotic therapy is lacking. The goal of this guideline is to provide practicing orthopaedic surgeons concise recommendations for the preoperative management of common contemporary antithrombotics in the setting of elective arthroplasty using evidence-based guidelines from other medical specialties. All arthroplasty procedures are considered high bleeding risk in accordance with collaborative AAOS and ACC guidelines. Orthopaedic surgeons should collaborate with their colleagues in cardiology, anesthesia, and other specialties when planning perioperative antithrombotic interruption, particularly in the case of medically complex patients such as those with known risk factors for bleeding and clotting disorders. Resumption of antithrombotic therapy after arthroplasty is beyond the scope of this discussion; this should be performed in accordance with cardiology and anesthesia recommendations.

Introduction

Antithrombotic medications can be subdivided into two basic classes: anticoagulants and antiplatelets.[1,2] The essential components for thrombus formation include fibrin and platelets. Although fibrin plays a role in both arterial and venous thromboembolic (VTE) disease, it is more relevant for venous thromboembolism prevention. On the other hand, platelets are essential for the development of arterial thrombosis. Anticoagulants inhibit the formation of fibrin clots and are effective in the prevention of both venous and arterial thrombosis, whereas antiplatelet medications are used primarily for the management of arterial disease.[3] Some common indications for antithrombotic therapy include chronic atrial fibrillation (AF), thrombophilia, recent or recurrent venous thromboembolism, recent percutaneous coronary intervention (PCI), cardiac valve replacement, coronary artery bypass graft surgery (CABG), and known malignancy.[4–6] Given the various indications for antithrombotic therapy and patient heterogeneity, defining the risk-benefit ratio can be challenging.

It is estimated that approximately six million people worldwide currently require chronic antithrombotic therapy.[2] Up to 250,000 or 10% of patients in North America alone require temporary antithrombotic interruption (ATI) annually for surgical procedures.[1,2] Orthopaedic surgeons should always collaborate with their colleagues in cardiology, anesthesia, and other specialties during the preoperative evaluation of a medically complex patient, including those on antithrombotics (Table 1, Table 2 and Table 3), for appropriate risk stratification. When considering ATI, the risk of a thrombotic event must be weighed against the risk of bleeding. Patient factors that increase perioperative bleeding risk include hemophilia, liver disease, renal disease, and a history of major bleeding.[7] However, all patients undergoing total joint arthroplasty (TJA) have high bleeding risk in accordance with the AAOS, ACC, and ASRA guidelines.[1,7,8]

A rapidly evolving topic in this realm is the use of tranexamic acid (TXA), an antifibrinolytic medication, in the perioperative setting to decrease blood loss. TXA has been shown to be efficacious in reducing blood loss regardless of the method of administration (IV, topical, or oral). Although more research is needed to determine the safety of TXA in patients at high risk for VTE, the lack of evidence proving harm and its generally well-documented safety profile thus far is reassuring. These data are summarized in the recently published combined clinical practice guidelines led by the American Association of Hip and Knee Surgeons.[9]

Although most TJAs in the United States are completed under general anesthesia, neuraxial anesthesia is increasingly popular for elective arthroplasty, and the risks of epidural and intrathecal hemorrhage must be considered in addition to surgical site bleeding. The incidence of spinal hematoma after neuraxial anesthesia is rare and difficult to estimate but frequently results in catastrophic permanent neurologic dysfunction.[10]

AF is the most prevalent sustained arrhythmia; antithrombotics are prescribed for patients with AF to reduce the risk of stroke and systemic embolism.[1] For patients with nonvalvular AF, tools have been developed to predict the risk of thrombosis.[2] The CHADS2 and more recent CHA2DS2-VASc (see Table 4) scoring systems were developed to stratify the risk of thrombotic events.[11,12] The annual stroke risk without antithrombotic therapy can range from as low as 1.9% (CHADS2 score 0) to as high as 18.2% (CHADS2 score >5).[11] The CHA2DS2-VASc scoring system improves the predictive value by incorporating additional risk factors with an increased emphasis on age.[12] Using CHA2DS2-VASc, the annual stroke risk without antithrombotic therapy has been reported to be as low as 0% (CHA2DS2-VASc score 0) to as high as 100% (CHA2DS2-VASc score 9).[12] In regard to valvular AF, all patients are considered to be at high risk for a thrombotic event.[2]

Previous VTE is a strong risk factor for recurrent thromboembolic events. Without antithrombotic therapy, patients with a previous VTE more than 12 months ago are considered to be at low risk (annual rate <5%), whereas those with a VTE within the past 3 to 12 months are at moderate risk (annual rate 5% to 10%) and patients with a VTE in the past 3 months are at high risk (annual rate >10%) for recurrence, propagation, and embolization of thrombi.[2] Elective procedures including TJA should be delayed in patients with a thrombotic event within the past 3 months.[1] Hypercoagulable disorders such as factor V Leiden, activated protein C resistance, protein C or S deficiency, antithrombin deficiency, and prothrombin G20210A mutation increase the risk of VTE, but specific recommendations regarding discontinuation intervals are not provided by ACC, ACCP, or ASRA guidelines.

Patients with coronary artery disease treated with PCI are another commonly encountered population on chronic antithrombotic therapy. Dual antiplatelet therapy (DAPT) is typically used after PCI to decrease the risk of stent thrombosis. Although the duration of DAPT in patients who receive drug-eluting stents (DES) and bare-metal stents is controversial and beyond the scope of this article, it is well-demonstrated that discontinuation of DAPT in the immediate weeks after stent placement is a strong risk factor for stent thrombosis.[13] The 2016 ACC/AHA guidelines recommend delaying elective procedures such as TJA in patients with bare-metal stent placement within the past 30 days and DES placement in the past 6 months.[13] Of note, this updates the previous 2014 guideline recommendation of delaying elective noncardiac surgery for one year after PCI with DES placement.[14]

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