Antithrombotic therapy is increasingly used to either reduce the risk of or treat thromboembolic episodes in patients with various medical conditions such as ischemic and valvular heart disease, atrial fibrillation (AF), cerebrovascular disease, peripheral arterial disease, venous thromboembolism (VTE) and hypercoagulable diseases. Antithrombotics include medications classified as anticoagulants or antiplatelets. Anticoagulants work by interfering with the native clotting cascade and consist of four main classes: vitamin K antagonists (VKA), heparin derivatives, direct factor Xa inhibitors, and direct thrombin inhibitors. Direct oral anticoagulants (DOACs) refer to dabigatran (a direct thrombin inhibitor) and the factor Xa inhibitors (apixaban, rivaroxaban, and edoxaban).
Antiplatelets, on the other hand, work by decreasing platelet aggregation and thus preventing thrombus formation; they include P2Y12 receptor inhibitors, protease-activated receptor-1 inhibitors, glycoprotein IIb/IIIa receptor inhibitors, acetylsalicylic acid (ASA), and nonsteroidal anti-inflammatory drugs. All of these agents may directly cause or increase the risk of gastrointestinal (GI) bleeding from luminal sources such as ulcers or diverticula, as well as after endoscopic interventions such as polypectomy. However, there is also a risk of thromboembolic consequences if some of these agents are withheld. Thus, the management of patients receiving antithrombotic agents and undergoing GI endoscopy represents an important clinical challenge and something that every GI physician has to deal with routinely.
The goal of this review is to discuss the optimal strategy for managing antithrombotics in patients undergoing elective endoscopy based on current available evidence and published clinical guidelines.1-4 Much of our discussion will review recommendations from the recently published joint American College of Gastroenterology (ACG) and Canadian Association of Gastroenterology (CAG) guidelines on management of anticoagulants and antiplatelets in the periendoscopic period by Abraham et al.4
Factors that guide decision-making
The two most vital factors to consider prior to performing endoscopic procedures in patients receiving antithrombotic therapy are to assess the risk of bleeding associated with the procedure and to assess the risk of thromboembolism associated with the underlying medical condition for which the antithrombotic agents are being used. In addition, it is also important to keep in mind the individual characteristics of the antithrombotic agent(s) used when making these decisions.
Estimating procedure-related bleeding risk
Various endoscopic procedures have different risks of associated bleeding. Although guidelines from GI societies may differ when classifying procedures into low or high risk, it is important to know that most of the original data on postprocedural bleeding risks are from studies conducted in patients who are not on complex antithrombotic regimens and thus may not accurately reflect the bleeding risk of patients using newer antithrombotic therapies.1,4-7
Traditionally, some of the common low-risk procedures have included diagnostic EGD and colonoscopy with or without biopsy, ERCP without sphincterotomy, biliary stent placement, and push or balloon-assisted enteroscopy. On the other hand, endoscopic procedures associated with interventions are known to have higher bleeding risk, and other procedural factors can influence this risk as well.8 For example, polypectomy, one of the most common interventions during endoscopy, is associated with bleeding risk ranging from 0.3% to 10% depending on multiple factors including polyp size, location, morphology (nonpolypoid, sessile, pedunculated), resection technique (cold or hot forceps, cold or hot snare), and type of cautery used.9 For some procedures, such as routine screening colonoscopy, however, the preprocedure estimate of bleeding risk can be uncertain because it is unclear if a high risk intervention (e.g., polypectomy of large polyp) will be necessary. For example, in the most recent ACG/CAG guidelines, colonoscopy with polypectomy < 1cm is considered a low/moderate risk bleeding procedure, whereas polypectomy > 1cm is considered high risk for bleeding.4 In these situations, the management of antithrombotic medications may depend on the individual patient’s risk of thrombosis and the specific antithrombotic agent. In the example of a patient undergoing colonoscopy while on antithrombotic medications, the bleeding risk associated with polypectomy can potentially be reduced by procedural techniques such as preferential use of cold snare polypectomy. Further high-quality data on the optimal procedural technique to reduce postpolypectomy bleeding in patients on antithrombotic medications is needed to help guide management.