What Surgeons Need to Know About the Recent Updates to the CHEST Guidelines on Antithrombotic Therapy for Venous Thromboembolic Disease and Perioperative Management of Antithrombotic Therapy

The last decade has seen tremendous advancements in anticoagulant and antiplatelet medications. Antithrombotic therapy now includes vitamin K antagonists (VKAs), direct oral anticoagulants (DOACs), antiplatelet agents, unfractionated heparin, low molecular weight heparin (LMWH), and combination regimens. With surgical patients taking these newer medications and combination regimens, perioperative management has become complex for elective surgeries and is even more challenging for emergency surgeries. Hence, it is important for surgeons to understand the perioperative management of antithrombotic medications, appropriate treatment regimens, and duration for the management of venous thromboembolism (VTE) based on recently published evidence. Fortunately, the American College of Chest Physicians publishes guidelines with updates on antithrombotic therapy. In August 2021, the second update to the ninth edition of Antithrombotic Therapy for VTE Disease was published. This update includes 4 new guidance statements and 8 substantially modified statements compared with the ninth edition published in 2012 and the subsequent first update from 2016.1–3 In November 2022, an update to the Perioperative Management of Antithrombotic Therapy was published. This update now includes 43 guidance statements, with 20 new and 23 revised or expanded statements, compared with the 11 guidance statements from the 2012 update.4,5 Together, these publications provide a comprehensive roadmap for the perioperative management of antithrombotic therapy and VTE treatment. However, the combined 87 pages of text, tables, and figures, not including references, may limit the number of surgeons who become aware of the new or revised statements. The goal of this article is to increase awareness of these two recently updated guideline documents among surgeons and to provide a summary of the most salient new or revised guideline statements that affect the management of surgical patients. ANTITHROMBOTIC THERAPY FOR VTE DISEASE Of the 29 recommendations made in the 2021 update, there are 20 guidance statements on initial management (statements 1–20), 1 on the duration of the treatment phase (statement 21), 7 on extended-phrase therapy (statements 22-28), and 1 on complications of VTE (statement 29). Impactful new or revised statements from the August 2021 update are summarized further. Important changes have been made to acute VTE treatment in the setting of cancer. The guidelines now recommend treating cancer-associated thrombosis with DOACs over VKAs for the first 3 months of treatment phase therapy when the prior recommendation was to use LMWH. The guidelines continue to recommend DOACs over VKAs for the treatment of acute VTE in patients without active cancer. New or revised statements have been made regarding extended-phase treatment for VTE. For patients with transient risk factors, the guidelines do not recommend extended-phase anticoagulation. For patients without transient risk factors, revised guidelines now recommend extended-phase anticoagulation with DOACs, or VKAs for patients who cannot receive DOACs. There are also new statements to provide multiple therapeutic regimen options for treating patients with extended-phase therapy. Specifically, reduced-dose apixaban or rivaroxaban is now recommended over full-dose therapy, and reduced-dose DOACs are now recommended over aspirin or no therapy. Lastly, for patients with unprovoked proximal deep vein thrombosis or pulmonary embolism who are stopping anticoagulation therapy, a new guidance statement suggests administering aspirin over no aspirin to prevent recurrent VTE. Finally, there are some notable new or revised disease-specific statements. For patients with cerebral vein thrombosis, the new guidance recommends anticoagulation therapy for 3 months over no therapy. VKAs are now recommended over DOACs for patients with antiphospholipid syndrome who develop an acute VTE. For patients with superficial venous thrombosis, guidelines recommend treatment with fondaparinux 2.5 mg daily over prophylactic or therapeutic LMWH, and rivaroxaban 10 mg daily as a reasonable alternative to fondaparinux. PERIOPERATIVE MANAGEMENT OF ANTITHROMBOTIC THERAPY The 2022 update provides antithrombotic therapy recommendations on VKAs (statements 1–15), bridging anticoagulation (statements 16–21), DOACs (statements 22–28), and antiplatelet agents (statements 29–43). It also addresses the following main perioperative questions every surgeon must answer for patients prescribed any of these medications: (1) Is interruption of the antithrombotic regimen recommended for elective surgery?; (2) How long should the medication be held before surgery and when should the medication be resumed after an elective surgery?; and (3) When therapy is interrupted, is bridging therapy recommended? The following are the salient new or revised guidance statements on perioperative management of antithrombotic therapy for each category of medication. For VKA management, the 2022 guidance statements were modified to be more specific regarding interruption and/or the need for bridging therapy. For example, revised guidelines recommend that for patients requiring VKA interruption for elective surgery, warfarin should be interrupted ≥5 days before and resumed within 24 hours of surgery at the patient’s usual dose (Fig. 1). New guidelines recommend that patients taking VKAs for a mechanical heart valve, atrial fibrillation, or VTE therapy no longer require bridging therapy with heparin when the VKA is interrupted. However, for patients undergoing pacemaker or implantable cardioverter defibrillator implantation, VKA therapy should continue over interruption and heparin bridging. Patients undergoing a colonoscopy with polypectomy are not recommended to have bridging therapy with heparin during VKA interruption. Lastly, for patients receiving LMWH for bridging therapy, new guidelines recommend administering the last preoperative dose ~24 hours before and the first postoperative dose at least 24 hours after the elective surgery and recommend against the routine measurement of anti-factor Xa levels.FIGURE 1: Flowchart of guidance recommendations regarding perioperative management of antithrombotic and antiplatelet agents. Additional visual representation with stratification by procedural bleeding risk and creatinine clearance for dabigatran is provided in Figures 1 to 3 of the 2022 Perioperative Management of Antithrombotic Therapy update.4 Created using BioRender.com. ASA indicate aspirin.Specific guidance has been provided regarding the management of DOACs in the perioperative period (Fig. 1). Most importantly, new guidance statements recommend that for patients taking DOACs, bridging therapy is not recommended. For patients taking apixaban, edoxaban, or rivaroxaban, new guidelines recommend stopping these medications 1 to 2 days before elective surgery. However, for patients taking dabigatran, the guidelines recommend stopping 1 to 4 days before the surgery. The guidance statements recommend resuming the DOACs >24 hours after the elective surgery and recommend against routine DOAC coagulation function testing to guide management. Finally, there are also new and revised guidance statements for antiplatelet agents. Revised guidance statements now recommend continuing aspirin for patients without high surgery-related bleeding risk for elective noncardiac surgery. For patients requiring aspirin interruption, revised guidance statements now recommend stopping aspirin ≤7 days before and resuming it ≤24 hours after the elective surgery (Fig. 1). For patients undergoing cardiac surgery, new guidance statements recommend continuing aspirin but suggest interruption of P2Y12 inhibitors. As with DOACs, the guidance statements recommend against routine platelet function testing to guide perioperative management. For elective noncardiac surgeries, new guidelines recommend stopping clopidogrel 5 days before, ticagrelor 3 to 5 days before, and prasugrel 7 days before the surgery. Lastly, for patients with coronary stents placed within the prior 3 to 12 months who are receiving dual therapy with aspirin and a P2Y12 inhibitor, revised guidance recommends stopping the P2Y12 inhibitors before the elective surgery and recommends against routine bridging therapy with a glycoprotein IIb/IIIa inhibitor, cangrelor, or LMWH. THE WAY FORWARD It is important for surgeons to be aware of the recent updates to both CHEST guideline documents, given the prevalence of anticoagulation therapy and the incidence of VTE occurrence in surgical patients. Furthermore, the management of antithrombotic therapies in the perioperative period and for VTE treatment has become a major focus of malpractice litigation. Although these guidelines provide important recommendations for the complex management of antithrombotic medications, much remains unknown. Additional research is needed regarding the perioperative management of DOACs before regional anesthesia, the management of DOACs for patients with severe chronic kidney disease, and the management of dual antiplatelet therapy before surgical procedures. Most importantly, these guidelines do not make recommendations on reversal strategies for antithrombotic medications in urgent or emergent cases. Even with these limitations, the American College of Chest Physicians has provided surgeons with an invaluable resource for the perioperative management of antithrombotic therapy and VTE treatment; it is now up to us to apply these evidence-based recommendations to the management of our surgical patients.