HAS-BLED Score
Assess bleeding risk in anticoagulated atrial fibrillation (AF) patients using the HAS-BLED score. Identify modifiable risk factors before starting or adjusting anticoagulation therapy.
Based on: ESC 2020 · Pisters 2010
Input
Clinical reasoning
A 72-year-old male with AF on warfarin. BP 165/95 mmHg, TTR 52% over the past 6 months. No prior bleeding or stroke. Drinks 2–3 glasses of wine daily.
Should anticoagulation be stopped?
A 78-year-old woman on apixaban for AF. Prior TIA (S), age >65 (E), CKD stage 3 (A-renal). Blood pressure controlled, no labile INR, no alcohol, no antiplatelets.
Should anticoagulation be stopped?
Overview
HAS-BLED quantifies one-year major bleeding risk in patients with atrial fibrillation. High scores identify modifiable risk factors to address — not a reason to withhold anticoagulation.
Evidence Summary
About HAS-BLED
HAS-BLED was developed by Pisters et al. (2010) using the Euro Heart Survey dataset of 3,978 AF patients followed over one year. The score quantifies 9 clinical factors associated with major bleeding on anticoagulation, with a maximum score of 9.
Interpreting the score
A score of ≥3 indicates elevated bleeding risk. In most AF patients, net clinical benefit of anticoagulation still outweighs bleeding risk even at high HAS-BLED scores (ESC 2020). The score's primary value is identifying actionable targets: uncontrolled hypertension, labile INR, and concurrent antiplatelet or NSAID use are directly modifiable.
Clinical use
HAS-BLED is a risk modification tool, not a restriction tool. A high score should prompt intervention on modifiable factors — not withdrawal of anticoagulation.
In practice, HAS-BLED is used alongside CHA₂DS₂-VASc — the two scores answer different questions. CHA₂DS₂-VASc establishes the indication; HAS-BLED guides how to make anticoagulation safer. For modifiable factors such as uncontrolled hypertension, labile INR, and concurrent antiplatelet or NSAID use, targeted correction before starting or alongside anticoagulation can meaningfully lower the score without stopping therapy. Non-modifiable factors (age, prior stroke, chronic organ disease) shift the clinical goal from risk reduction to closer monitoring.