CHA₂DS₂‑VASc Score Helper

This tool helps estimate annual stroke risk in non-valvular atrial fibrillation (AFib). It's for adults with AFib to better understand this common clinical score, prepare for appointments, and discuss prevention with their doctor. All calculations run offline in your browser.

Educational only, not medical advice. This is a discussion aid, not a diagnostic tool. Clinical decisions require professional judgment.

Risk Factor ChecklistTotal: 0 points

Check all that apply. Each checked item adds the displayed points to your total CHA₂DS₂‑VASc score.

Congestive Heart Failure (or LVEF ≤40%) 1 point

Hypertension (high BP, treated or untreated) 1 point

Age 75 years or older 2 points

Diabetes Mellitus (Type 1 or 2) 1 point

Stroke, TIA, or Thromboembolism history 2 points

Vascular Disease (MI, PAD, aortic plaque) 1 point

Age 65‑74 years 1 point

Female sex 1 point

Interpretation & Discussion Notes

0 CHA₂DS₂‑VASc Score

Points are automatically summed as you check boxes above.

Typical Annual Stroke Risk (based on score)

Very low risk. For AFib patients with a score of 0 (male) or 1 (female), guidelines often suggest no anticoagulation may be needed, but individual factors matter.

Prepare for Your Appointment

Your current score suggests discussing stroke prevention strategies with your doctor may be relevant. Consider asking about:

Confirming your atrial fibrillation diagnosis
Reviewing your risk factors for accuracy

Understanding Your CHA₂DS₂‑VASc Score

The CHA₂DS₂‑VASc score is a clinical tool used by cardiologists and primary care doctors to estimate the annual risk of stroke in patients with non‑valvular atrial fibrillation (AFib). It helps guide decisions about anticoagulant medication (blood thinners).

How to Use This Tool

Check all risk factors that apply to you based on your medical history and current status.
Your total score updates automatically. Higher scores indicate higher estimated stroke risk.
Review the interpretation and typical risk percentage. This is an estimate, not a prediction.
Use the "Prepare for Your Appointment" notes to write down questions for your doctor.

Realistic Examples

Patient	Risk Factors	Score	Typical Annual Stroke Risk
Male, 60, healthy	None	0	~0.5%
Female, 78, hypertension	Age ≥75, Female, HTN	4	~4.8%
Male, 70, diabetes, prior stroke	Age 65-74, Diabetes, Stroke history	5	~7.2%

Key Definitions & Common Pitfalls

Congestive Heart Failure: Symptomatic heart failure OR documented left ventricular ejection fraction (LVEF) ≤40%.
Hypertension: History of high blood pressure, whether currently treated or not.
Vascular Disease: Includes prior heart attack (MI), peripheral artery disease (PAD), or aortic plaque.
Female Sex: Adds 1 point. The increased risk is thought to be age‑related; younger women with AFib without other risk factors may not have elevated stroke risk.
Important: This score is only validated for non‑valvular AFib. It does not apply to patients with mechanical heart valves or moderate‑to‑severe mitral stenosis.

Frequently Asked Questions

How accurate is this score?

The score provides population‑based risk estimates. Your personal risk may differ due to genetics, medication adherence, lifestyle, and other unmeasured factors. It is a starting point for discussion.

I scored 0 (male) or 1 (female). Does that mean I don't need blood thinners?

Guidelines often suggest anticoagulation may not be needed for these low scores, but the decision is individual. Your doctor will consider bleeding risk, patient preference, and other clinical factors.

What's the difference between "Stroke history" and "Vascular disease"?

"Stroke history" includes ischemic stroke, TIA (transient ischemic attack), or systemic embolism. "Vascular disease" refers to problems in the arteries like prior heart attack or peripheral artery disease.

When should I seek immediate medical help?

If you experience sudden signs of stroke (face drooping, arm weakness, speech difficulty, time to call 911), new chest pain, severe shortness of breath, or palpitations with dizziness, seek emergency care regardless of your score.

Formulas & Assumptions

Scoring: CHF=1, HTN=1, Age≥75=2, Diabetes=1, Stroke/TIA/Thromboembolism=2, Vascular Disease=1, Age 65‑74=1, Female Sex=1. Maximum possible score = 9.
Risk Conversion: Approximate annual stroke risk percentages based on the 2010 Lip et al. validation study: Score 0=0.5%, 1=1.5%, 2=2.5%, 3=3.5%, 4=4.8%, 5=7.2%, 6=9.7%, 7=11.2%, 8=13.6%, 9=15.7%.
Rounding: Percentages shown are rounded to one decimal place. Calculations use unrounded values internally.
Assumptions: The tool assumes non‑valvular atrial fibrillation. It does not account for bleeding risk (e.g., HAS‑BLED score) or other individual clinical nuances.

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