CHA₂DS₂-VASc (Lip GY et al., Chest 2010; 137: 263-272) is a validated risk score for thromboembolic complications in patients with nonvalvular atrial fibrillation. It extends the earlier CHADS₂ score by adding vascular disease, female sex, and the 65-74 year age category for more precise risk stratification.
The score is endorsed by the ESC 2020 and ACC/AHA/HRS 2023 guidelines on atrial fibrillation. Its result drives a key clinical decision: whether long-term anticoagulation is indicated.
Current thresholds: a score of ≥ 2 in men and ≥ 3 in women warrants anticoagulation (direct oral anticoagulants, DOACs, are preferred). A score of 1 in men and 2 in women calls for individualized discussion, weighing bleeding risk (in parallel with HAS-BLED). A score of 0 in men and 1 in women (from sex alone) means anticoagulation is not indicated.
When to use
Established diagnosis of nonvalvular AF - paroxysmal, persistent, or permanent.
Deciding whether to start or continue anticoagulation before cardioversion, ablation, or device implantation.
Routine reassessment (at least annually) - the score can rise over time with age and new comorbidities.
Documenting the rationale for DOAC prescription for insurance or formulary purposes.
Prior MI, symptomatic peripheral artery disease, or aortic plaque on imaging.
Clinical example
Case
68-year-old woman with permanent AF. History: hypertension for 10 years, type 2 diabetes on metformin, ischemic stroke 3 years ago. Creatinine 78 µmol/L, GFR 72 mL/min.
Very high stroke risk (~10%/year without treatment). Anticoagulation is clearly indicated. DOACs (apixaban, rivaroxaban, dabigatran) are the preferred agents. Assess HAS-BLED in parallel to individualize management, but a high bleeding risk score alone is not a contraindication.
Limitations and cautions
Does not apply to valvular AF (moderate/severe mitral stenosis, mechanical valve prosthesis) - anticoagulation is indicated regardless of score in these cases.
Does not account for time since stroke - starting anticoagulation within the first 14 days after an acute event requires separate assessment.
In severe CKD (GFR < 30), DOAC selection and dosing require adjustment not reflected in the score.
Does not assess bleeding risk - that is a separate task (HAS-BLED).
If a woman scores 1 point from sex alone, is anticoagulation needed?
No. Female sex alone is a risk modifier, not an independent risk factor. The anticoagulation threshold in women is ≥ 3 points; a score of 1 (sex alone) is treated as equivalent to zero risk.
Can this be used in a patient with atrial flutter?
Yes. Guidelines apply the score equally to AF and atrial flutter, since thromboembolic risk is comparable.
Is aspirin an alternative to anticoagulation?
No. Its efficacy for stroke prevention is significantly lower, while bleeding risk is comparable. An exception is concomitant coronary artery disease with its own indications for antiplatelet therapy.
Warfarin or a DOAC - which to choose?
In nonvalvular AF, DOACs are first-line (fewer interactions, no INR monitoring needed, lower risk of intracranial hemorrhage). Warfarin remains the choice in valvular AF and severe CKD.
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Aleksandr A. Aulov
Physician, internal medicine, Sechenov School — independent medical education platform.
Calculators are compiled from the original publications and current clinical guidelines. Interpretation thresholds follow the source study unless stated otherwise.
This calculator is intended for healthcare professionals. Do not use it for self-diagnosis or self-treatment. Management decisions are made by the treating clinician based on the full clinical picture of the individual patient.
Last clinical review: April 28, 2026 ·
Author: Aleksandr A. Aulov,
MD, internal medicine ·
Primary source: Lip GYH et al. Chest 2010; 137(2): 263-272