Related Subjects:
|AF - General
|AF and Anticoagulation
|AF and Rate Control
|AF and Rhythm Control and Cardioversion
|AF ECG
|DC cardioversion
🫀 Atrial Fibrillation – Anticoagulation Risk Assessment
In AF, anticoagulation decisions balance the risk of stroke (CHA₂DS₂-VASc) ⚡ against the risk of
bleeding (HAS-BLED) 💉. NICE recommends anticoagulation for most patients with
CHA₂DS₂-VASc ≥ 1 (men) or ≥ 2 (women).
⚡ CHA₂DS₂-VASc Score (Stroke Risk)
- CCF history (+1)
- Hypertension (+1)
- Age 65–74 (+1), >75 (+2)
- Diabetes mellitus (+1)
- Stroke/TIA/thromboembolism (+2)
- Vascular disease (MI, PAD, aortic plaque) (+1)
- Sex category: female (+1)
| Score | Estimated Yearly Stroke Risk (%) | Management |
|---|
| 0 | 0% | No anticoagulation |
| 1 | ~1.3% | Consider anticoagulation (men); in women, if only risk is “female sex”, omit |
| 2 | ~2.2% | Oral anticoagulants recommended |
| 3 | ~3.2% | Oral anticoagulants recommended |
| 4 | ~4.0% | Oral anticoagulants recommended |
| 5 | ~6.7% | Oral anticoagulants recommended |
| 6 | ~9.8% | Oral anticoagulants recommended |
| 7 | ~9.6% | Oral anticoagulants recommended |
| 8 | ~6.7% | Oral anticoagulants recommended |
| 9 | ~15.2% | Oral anticoagulants recommended |
💉 HAS-BLED Score (Bleeding Risk)
A score ≥3 = higher bleed risk (≈3.7 bleeds/100 patient-years). Not a contraindication, but
a flag for caution, review and modifiable risk factor control.
| Feature | Score |
|---|
| Hypertension (SBP >160 mmHg) | +1 |
| Abnormal renal/liver function | +1 each |
| Stroke history | +1 |
| Bleeding history/anaemia | +1 |
| Labile INRs (if on warfarin) | +1 |
| Elderly >65 | +1 |
| Drugs (antiplatelets/NSAIDs) or Alcohol | +1 each |
💊 Anticoagulant Options
| Drug | Mechanism | Dosing Notes | Reversal |
|---|
| Warfarin | Vitamin K antagonist | Target INR 2–3 (2.5–3.5 in high risk). Many food & drug interactions. | Vitamin K + PCC (Octaplex/Beriplex) |
| Dabigatran | Direct thrombin inhibitor | Avoid if CrCl <30. Reduce dose in age >80 or renal impairment. | Praxbind (idarucizumab) |
| Apixaban | Factor Xa inhibitor | Reduce dose if ≥80yrs, weight ≤60kg, or renal impairment. | PCC (Octaplex/Beriplex) |
| Rivaroxaban | Factor Xa inhibitor | Once daily. Reduce if CrCl 15–49. Avoid if <15. | PCC |
| Edoxaban | Factor Xa inhibitor | Reduce in renal impairment or weight ≤60kg. Avoid if ESRD/dialysis. | PCC |
🔑 Clinical Pearls
- Bleeding and stroke risks overlap – don’t use HAS-BLED to deny anticoagulation; instead use it to mitigate risks.
- DOACs are preferred first-line (NICE NG196, 2021) unless contraindicated (e.g. valvular AF, severe renal impairment).
- Warfarin still used in mechanical valves or severe mitral stenosis.
- Reversal agents are now available for both warfarin and DOACs.
