According to an assessment of bleeding risk scores for patients with atrial fibrillation treated with oral anticoagulants (OACs), reinitiation of OACs after a major bleeding event can significantly reduce thromboembolism and all-cause mortality and should be considered on an individualized basis. Results from the assessment were published in Expert Review of Hematology.
Although OACs reduce the risk for thromboembolism in patients with AF, they are associated with an increased risk of bleeding due to their mechanism of action. Bleeding risk is complex, and after a major bleeding event, a multidisciplinary team should regularly assess a patient’s risk prior to treatment, including reinitiating OAC therapy. The authors emphasized that even in patients with a high risk of bleeding, continued OAC therapy is warranted, along with frequent and close monitoring of bleeding risk.
Researchers conducted a PubMed literature search for articles published between 2006 and 2019 that evaluated bleeding risk scores. The literature search identified 6 bleeding risk scores: Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT); Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA); hypertension, abnormal renal or liver function, stroke, bleeding history or predisposition, labile International Normalised Ratio (INR), elderly, drugs or alcohol (HAS-BLED); age, biomarkers, clinical history (ABC); hepatic or renal disease, ethanol abuse, malignancy, older age > 75 years, reduced platelet count or function, rebleeding risk, hypertension, anemia, genetic factors, excessive fall risk, stroke (HEMORR2HAGES); and the Outpatient Bleeding Risk Index (OBRI).
Bleeding risk scores typically stratify patients into low-, intermediate-, and high-risk groups, though HAS-BLED groups low- and intermediate-risk patients into a single low-intermediate-risk group. Reversible risk factors for bleeding should be considered across risk categories and not just in patients with a high risk of bleeding, and these risk factors should be addressed when possible.
Reversible risk factors for bleeding include use of antiplatelet and nonsteroidal anti-inflammatory drugs (NSAIDs), hypertension, alcohol abuse, and time in therapeutic range for patients on vitamin K antagonists. Factors that are potentially reversible include abnormal renal and liver function, anemia, and reduced platelet count or function. Irreversible factors include older age, cancer, genetic factors, history of stroke, history of major bleeding, and cirrhotic liver disease.
After a major bleeding event, absolute contraindications to restarting OACs are rare. In these cases, nonpharmacologic approaches, including permanent carotid filters and left atrial appendage occlusion, can provide therapeutic options for reducing the risk of stroke in patients with atrial fibrillation.
The authors noted limitations of observational studies included high heterogeneity, the difficulty in assessing direct causality between OAC exposure and clinical outcomes, and the limited number of analyses. They suggested further sufficiently powered prospective cohort studies or randomized clinical trials are needed to elucidate the optimal reinitiation of OACs after a major bleeding event.
- Kozieł M, Ding WY, Kalarus Z, Lip GYH. Considerations when restarting anticoagulants in patients with atrial fibrillation after bleeding [published online July 23, 2019]. Expert Rev Hematol. doi:10.1080/17474086.2019.1647779