About

The CHA₂DS₂-VASc score is the standard clinical prediction rule for estimating the risk of stroke in patients with non-rheumatic atrial fibrillation. It improves upon the older CHADS₂ score by identifying "truly low risk" patients more accurately. Cardiologists and general practitioners use this tool to determine the necessity of oral anticoagulation therapy. A score of 0 in males or 1 in females suggests no therapy is needed, whereas higher scores strongly indicate the benefit of anticoagulation to prevent ischemic stroke.

Formulas

The score sums weighted risk factors:

Score = CHF + HTN + Age₇₅ + Diabetes + Stroke + Vasc + Age₆₅ + SexCat

Weights:

Stroke/TIA/Thromboembolism → 2 ptsAge ≥ 75 → 2 ptsAll others (CHF, HTN, DM, Vasc, Age 65-74, Female) → 1 pt

Reference Data

Score	Adjusted Stroke Rate (%/year)	Recommendation
0	0.0%	No antithrombotic therapy
1	1.3%	Consider oral anticoagulant (Based on gender)
2	2.2%	Oral anticoagulant recommended
3	3.2%	Oral anticoagulant recommended
4	4.0%	Oral anticoagulant recommended
5	6.7%	Oral anticoagulant recommended
6	9.8%	High risk
7	9.6%	High risk
9	15.2%	Extreme risk

Frequently Asked Questions

Yes, female sex is an independent risk factor and adds 1 point. However, if a female patient has NO other risk factors (Score = 1), the actual risk is low, and anticoagulation is typically not recommended solely based on gender.

Vascular disease in this context includes prior myocardial infarction, peripheral artery disease, or complex aortic plaque.

This is a statistical artifact from the validation cohorts (e.g., Friberg et al. 2012). Sample sizes for very high scores are smaller, leading to wider confidence intervals, but the trend remains: higher score equals higher risk.