Written by Amanda Mathews
The new DOAC score had stronger predictive performance for major bleeding in patients on anticoagulation for atrial fibrillation (A-fib) compared to the HAS-BLED score.
Is HAS BLED a HAS BEEN?
Many clinicians have used the HAS-BLED score for bleeding risk stratification for patients being started on anticoagulation for A-fib. However, it was validated in patients taking warfarin, which is rarely prescribed for A-fib anymore. Researchers developed, refined, and externally validated a clinical decision making tool, the DOAC Score, to risk stratify patients being prescribed direct oral anticoagulants (DOAC).
Researchers developed their initial risk score starting with a secondary analysis of the RE-LY trial and refined it using the GARFIELD-AF registry. They externally validated it using the COMBINE-AF clinical trial cohort and the RAMQ administrative database.
For the development cohort, 6.8% of patients developed a major bleeding event in the interim follow-up. Median follow-up was 1 year. Patients with a major bleeding event were older, more likely to take aspirin or dual antiplatelet therapy, and more likely to have diabetes. In the refinement cohort, 1.1% experienced a major bleeding event, and in the validation cohorts, major bleeding rates were 2.2% and 2.7%. In both validation cohorts, the DOAC score had stronger predictive performance compared to the HAS BLED score.
There were a few limitations to this study. The DOAC score was validated for major bleeding outcomes only, not all bleeding outcomes. The rate of major bleeding was highest in the development cohort study and much lower in the other cohorts, which could have led to flawed weighting of variables from the model development stage.
How will this change my practice?
I have used the HAS-BLED score in the past to talk to patients about risk for bleeding when prescribing anticoagulation for A-fib. The variables and weighting applied in the DOAC score are reasonable and intuitive in my assessment. I would now feel comfortable using the DOAC score to assess risk if prescribing a standard dosing DOAC in this patient population.
Development and Validation of the DOAC Score: A Novel Bleeding Risk Prediction Tool for Patients With Atrial Fibrillation on Direct-Acting Oral Anticoagulants. Circulation. 2023 Sep 19;148(12):936-946. doi: 10.1161/CIRCULATIONAHA.123.064556. Epub 2023 Aug 25.