Patients at the lowest risk of thromboembolism are those with:
- mechanical aortic prostheses with no other stroke risk factors;
- atrial fibrillation with a CHADS2 score of zero to two; and/or
- a single VTE that occurred >12 months prior.
There are several approaches to identifying patients at greatest risk for bleeding. Location-specific modeling for upper GI bleeds (e.g. Rockall score) and lower GI bleeds (e.g. BLEED score) focus on the clinical presentation and/or endoscopic findings. General hemorrhage risk scores (e.g. HAS-BLED, ATRIA) focus on medical comorbidities. While easy to use, the predictive value of such scores as part of anticoagulation resumption after a GI hemorrhage remains uncertain.
Based on the above methods of risk stratification, patients at higher risk of thromboembolism and lower risk of bleeding will likely benefit from waiting only a short time interval before restarting anticoagulation. Based on the trial conducted by Witt and colleagues, anticoagulation typically can be reinitiated within four days of obtaining hemostatic and hemodynamic stability.2 Conversely, those at highest risk of bleeding and lower risk of thromboembolism will benefit from a delayed resumption of anticoagulation. Involvement of a specialist, such as a gastroenterologist, could help further clarify the risk of rebleeding.
The ideal approach for patients with a high risk of both bleeding and thromboembolism remains uncertain. Such cases highlight the need for an informed discussion with the patient and any involved caregivers, as well as involvement of inpatient subspecialists and outpatient longitudinal providers.
There remains a lack of evidence on the best method to restart anticoagulation. Based on small and retrospective trials, we recommend restarting warfarin at the patient’s previous home dose. The duration of inpatient monitoring following warfarin initiation should be individualized, but warfarin is not expected to impair coagulation for four to six days after initiation.
Little data is available with respect to the role of novel oral anticoagulants after a GI bleed. Given the lack of reversing agents for these drugs, we recommend exercising caution in populations with a high risk of rebleeding. Theoretically, given that these agents reach peak effect faster than warfarin, waiting an additional four days after the time frame recommended for starting warfarin is a prudent resumption strategy for novel oral anticoagulants.
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Table 1: Risk stratification for thromboembolism
Source: Adapted from Douketis JD, Spyropoulos AC, Spencer FA, et al. Perioperative management of antithrombotic therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e326S-350S.
Resumption of Antiplatelet Agents
The decision to resume antiplatelet therapy should also be highly individualized. In addition to weighing the risk of bleeding (as described in the previous section), the physician must also estimate the benefits of antiplatelet therapy in decreasing the risk of cardiovascular events.
In low-risk patients on antiplatelet therapy (i.e., for primary cardiovascular prevention) reinitiation after a bleeding episode can be reasonably delayed, because the risk of rebleeding likely outweighs the potential benefit of restarting therapy.
For patients who are at intermediate risk (i.e., those on antiplatelet agents for secondary prevention of cardiovascular disease), emerging evidence argues for early reinstitution after a GI bleed. In a trial published in Annals of Internal Medicine, Sung and colleagues randomized 156 patients to aspirin or placebo therapy immediately following endoscopically obtained hemostasis for peptic ulcer bleeding.4 All patients received PPIs. There was no significant difference in bleeding rates between the two groups, but delayed resumption of aspirin was associated with a significant increase in all-cause mortality.
gi bleed