From the Guidelines
The decision to start or stop anticoagulation for atrial fibrillation should primarily be based on the CHA₂DS₂-VASc score, not by comparing it with the HAS-BLED score. For most patients with atrial fibrillation, anticoagulation is recommended if the CHA₂DS₂-VASc score is 2 or higher for men and 1 or higher for women, as the stroke risk outweighs bleeding risk, according to the 2019 AHA/ACC/HRS guideline update 1. Common anticoagulants include warfarin (target INR 2-3), apixaban (5mg twice daily), rivaroxaban (20mg daily), dabigatran (150mg twice daily), and edoxaban (60mg daily).
Key Considerations
- The HAS-BLED score helps identify modifiable bleeding risk factors but should not typically be used to withhold anticoagulation, as stated in the guideline update 1.
- If the HAS-BLED score is high (≥3), focus on addressing reversible risk factors like uncontrolled hypertension, medication interactions, or excessive alcohol use while continuing anticoagulation in most cases.
- Regular reassessment of both stroke and bleeding risks is essential, with particular attention to kidney function, age, and medication interactions, as recommended by the guideline update 1.
Anticoagulation Therapy
- Selection of anticoagulant therapy should be based on the risk of thromboembolism, irrespective of whether the AF pattern is paroxysmal, persistent, or permanent, according to the guideline update 1.
- Renal function and hepatic function should be evaluated before initiation of a NOAC and should be reevaluated at least annually, as stated in the guideline update 1. This approach balances stroke prevention with bleeding risk management, recognizing that for most atrial fibrillation patients, the risk of stroke without anticoagulation exceeds the risk of serious bleeding with appropriate therapy, as supported by the guideline update 1.
From the Research
Comparison of HAS-BLED and CHADS2Vasc Scores
- The decision to stop or give anticoagulation long-term for atrial fibrillation (AF) depends on various factors, including the patient's risk of stroke and bleeding [ 2 ].
- The CHADS2Vasc score is used to assess the risk of stroke in patients with AF, while the HAS-BLED score is used to assess the risk of bleeding [ 2 ].
- A study published in 2011 found that the threshold for anticoagulation using warfarin was a CHADS2 score ≥2, but this threshold may be lower with newer, safer anticoagulants [ 2 ].
Anticoagulation Therapy
- New oral anticoagulants (NOACs) such as apixaban, dabigatran, and rivaroxaban have been shown to be effective in preventing stroke in patients with AF [ 3 ].
- A study published in 2017 found that apixaban had a lower risk of bleeding compared to warfarin, while rivaroxaban had a higher risk of bleeding [ 3 ].
- Another study published in 2014 found that apixaban had similar beneficial effects on stroke or systemic embolism and major bleeding compared to warfarin, irrespective of concomitant aspirin use [ 4 ].
Risk Assessment
- The risk of non-hemorrhagic stroke and systemic embolic events was similar with NOACs and warfarin, while the risk of intracranial bleeding was lower with NOACs [ 5 ].
- A study published in 2017 found that not all patients with AF need long-term anticoagulation, and the decision to start anticoagulation should be based on individual patient risk factors [ 6 ].
- The CHA2DS2VASc score can be used to assess the risk of stroke in patients with AF, and a score ≥2 indicates a higher risk of stroke [ 6 ].