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CHA₂DS₂-VASc Calculator

Stroke risk assessment for atrial fibrillation • NICE NG196

Clinical Context: This calculator is for patients with atrial fibrillation (AF) to assess annual stroke risk and guide anticoagulation decisions.

0
CHA₂DS₂-VASc Score
+1
+1
+2
+1
+2
+1
+1
+1

Note: Age categories are mutually exclusive. Select either 65-74 OR ≥75 (not both).

Risk Category
Annual Stroke Rate

Recommendation (NICE NG196)

Anticoagulation Options

    Bleeding Risk: Consider using ORBIT or HAS-BLED score to assess bleeding risk before initiating anticoagulation.

    About CHA₂DS₂-VASc

    CHA₂DS₂-VASc is a validated clinical prediction tool for assessing stroke risk in patients with atrial fibrillation (AF). It guides anticoagulation therapy decisions.

    When to use:

    • All patients with AF (paroxysmal, persistent, or permanent)
    • To determine need for oral anticoagulation
    • Annual review of AF patients

    Score Interpretation

    Risk Categories:

    • 0 (Male) / 1 (Female): Low risk - 0-1.3% annually
    • 1 (Male): Moderate risk - 1.3-2.2% annually
    • ≥2: High risk - ≥2.2% annually

    NICE NG196 Guidance: Offer anticoagulation to people with a CHA₂DS₂-VASc score of 2 or above (or score of 1 in males).

    Clinical Considerations

    • Assess bleeding risk (ORBIT/HAS-BLED)
    • DOACs preferred over warfarin (if suitable)
    • Patient preference and shared decision-making
    • Renal function assessment before DOAC
    • Review anticoagulation annually

    Evidence & Guidelines

    NICE NG196 - Atrial Fibrillation Europace - Original Validation Circulation - Clinical Application