Management of antithrombotic medications in elective endoscopy

Estimating thromboembolic risk

The risk of thromboembolic events in patients who are withholding their antithrombotic therapy for an endoscopic procedure depends on their underlying condition and individual characteristics. In patients who are on antithrombotic therapy for stroke prevention in non-valvular AF, the risk of cerebral thromboembolism in these patients is predictable using the CHA₂DS₂Vasc index.¹⁰ This scoring index includes heart failure, hypertension, age 75 years or older, diabetes mellitus, prior stroke or transient ischemic attack (TIA), vascular disease, age 65-74 years, and sex categories.

Patients with previous VTE on anticoagulation or those who have mechanical heart valves may have different risk factors for thromboembolic episodes. Among patients with VTE, time from initial VTE, history of recurrent VTE with antithrombotic interruption, and presence of underlying thrombophilia are most predictive of future thromboembolic risk. And for patients with mechanical heart valves, presence of a mitral valve prosthesis, and the presence or absence of associated heart failure and AF determine the annual risk of thromboembolic events. Bioprosthetic valves are generally considered low risk.

In patients with coronary artery disease (CAD), high thrombosis risk scenarios with holding antiplatelets include patients within 3 months of an acute coronary syndrome (ACS) event, within 6 months of a drug-eluting stent (DES) placement, or within 1 month of a bare metal coronary stent (BMS) placement. In addition, patients with ACS that occurred within the past 12 months of DES placement or within 2 months of BMS placement are also considered high risk.^11,12 Even beyond these periods, certain patients may still be at high risk of stent occlusion. In particular, patients with a prior history of stent occlusion, ACS or ST elevation myocardial infection, prior multivessel percutaneous coronary intervention, diabetes, renal failure, or diffuse CAD are at higher risk of stent occlusion or ACS events with alteration of antithrombotic therapy.¹³ Thus, modification of antithrombotic regimens in these patients should be cautiously approached.

Management of antithrombotics prior to elective endoscopy

In patients who need elective endoscopic procedures, if the indication for antithrombotic therapy is short-term, the procedure is probably best delayed until after that period.¹³ For patients on long-term or lifelong antithrombotic treatment, the decision to temporarily hold the treatment for endoscopy should occur after a discussion with the patient and all of the involved providers. In some high-risk patients, these agents cannot be interrupted; therefore, clinicians must carefully weigh the risks and benefits of the procedure before proceeding with endoscopy. For patients who are known to be undergoing an elective endoscopic procedure, antithrombotic medications may or may not need to be held prior to the procedure depending on the type of therapy. For example, according to the recent ACG/CAG guidelines, warfarin should be continued, whereas DOACs should be temporarily stopped for patients who are undergoing elective/planned endoscopic GI procedures.

Unfractionated heparin (UFH) administered as a continuous intravenous infusion can generally be held 3-4 hours before the procedure, given its short half-life. Low molecular weight heparin (LMWH), including enoxaparin and dalteparin, should be stopped 24 hours prior to the procedure.^2,14 Fondaparinux is a synthetic X-a inhibitor that requires discontinuation at least 36 hours preceding a high risk procedure. For patients on warfarin who are undergoing elective endoscopic procedures that are low risk for inducing bleeding, warfarin can be continued, as opposed to temporarily interrupted, although the dose should be omitted the morning of the procedure.⁴ For those who are undergoing high-risk endoscopic procedures (including colonoscopy with possible polypectomy > 1 cm), 5 days of temporary interruption without periprocedural bridging is appropriate in most patients. This is contrary to previous guidelines, which had recommended bridging for patients with a CHA2DS2Vasc score ≥ 2. Recent impactful randomized trials (BRIDGE and PERIOP-2) have called into question the benefit of periprocedural bridging with LMWH. Avoiding bridging anticoagulation was generally found to be similar to bridging in regard to prevention of thromboembolic complications, but importantly was associated with a decreased risk of major bleeding.^15,16 Of note, periprocedural bridging may still be appropriate in a small subset of patients, including those with mechanical valves, AF with CHADS2 score > 5, and previous thromboembolism during temporary interruption of VKAs. The decision to bridge or not should ideally be made in a multidisciplinary fashion.^15-20

Data are lacking on the ideal strategy for periendoscopic DOAC management. As mentioned above, for patients on DOACs who are undergoing elective endoscopic GI procedures, temporarily interrupting DOACs rather than continuing them is recommended. Currently, there are no randomized controlled trials addressing the management of DOACs in the periendoscopic period. However, based on five cohort studies, the ideal duration of DOAC interruption before endoscopic procedures may be between 1 and 2 days, excluding the day of the procedure.^21-25 This strategy allows for a short preprocedural duration of DOAC interruption and likely provides a balance between bleeding and thromboembolism risk. Importantly, there are no reliable laboratory assays to assess the anticoagulant effect of DOACs, and an individual patient’s degree of renal dysfunction may impact how long the DOAC should be held. In general, the anti-Xa drugs should be held for 1-2 days if the creatinine clearance (CrCl) is ≥ 60 mL/min, for 3 days if the CrCl is between 30 mL/min and 59 mL/min, and for 4 days if the CrCl is less than 30 mL/min.²⁶ For edoxaban, the recommendation is to hold at least 24 hours before high-risk procedures. The recommendation for stopping dabigatran is 2-3 days before a high-risk procedure in patients with CrCl more than 80 mL/min, 3-4 days prior if between 30 and 49 mL/min, and 4-6 days prior if less than 30 mL/min respectively.²⁷

In regard to antiplatelet management, ASA and the P2Y₁₂ receptor inhibitors (e.g. clopidogrel, prasugrel, and ticagrelor) are the most commonly utilized antiplatelets in patients undergoing endoscopic procedures. For patients who are on ASA monotherapy, whether 81 mg or 325 mg daily, for secondary cardiovascular prevention, no interruption of ASA therapy is necessary for elective procedures. The benefit of ASA for secondary cardiovascular prevention and the possible reduction in thrombotic events seen in RCTs of nonendoscopic surgical procedures is well known. However, there may be certain exceptions in which aspirin should be temporarily held. For example, short-term interruption of ASA could be considered in high risk procedures such as biliary or pancreatic sphincterotomy, ampullectomy, and peroral endoscopic myotomy. For patients on single antiplatelet therapy with a P2Y₁₂ receptor inhibitor who are undergoing elective endoscopic GI procedures, the recent CAG/ACG guidelines did not provide a clear recommendation for or against temporary interruption of the P2Y₁₂ receptor inhibitor. Although interruption of a P2Y₁₂ receptor inhibitor should theoretically decrease a patient’s risk of bleeding, the available evidence reported a nonsignificant increased bleeding risk in patients who stop a P2Y₁₂ receptor inhibitor for an elective endoscopic procedure compared with those who continue the medication.^28,29 Therefore, until further data are available, for patients on P2Y₁₂ receptor monotherapy, a reasonable strategy would be to temporarily hold therapy prior to high risk endoscopic procedures, assuming the patients are not at high cardiovascular risk. Clopidogrel and prasugrel have to be stopped 5-7 days prior to allow normal platelet aggregation to resume as opposed to ticagrelor, a reversible P2Y₁₂ receptor inhibitor that can be stopped 3-5 days prior.³⁰

Lastly, for patients who are on dual antiplatelet therapy (DAPT) for secondary prevention, continuation of ASA and temporary interruption of the P2Y₁₂ receptor inhibitor is recommended while undergoing elective endoscopy. Studies have shown that those who discontinued both had a much higher incidence of stent thrombosis compared with those who remained on aspirin alone.^4,28,31