If your patient presents a condition, select 'Yes'
Congestive heart failure
Female gender?
Stroke, TIA or thromboembolism history
Vascular disease
The patient is in the low risk group.

The annual risk of stroke is 0.2% and the risk of stroke/TIA or peripheral embolism is 0.3% per year. [1]

Anticoagulation therapy is not required. [2]

CHA2DS2-Vasc calculator is a useful tool to assess your patient with atrial fibrillation. Have you ever had a hard clinical decision to make? We're here to help you! The CHA2DS2-Vasc score considers seven stroke risk factors to score your patient's risk. You'll also get a short comment about the CHA2DS2-Vasc risk stratification and any further recommendations. With our tool for calculating the CHA2DS2-Vasc stroke risk, clinical assessment is faster and easier. It is important to notice, that if someone refers to 'CHADSVasc score' or 'CHADSVasc calculator', they mean this scale. But, if they mention the 'CHADS score', they might think of the older version of the scale. Find more in the last section of the text.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace a professional doctor's assessment. Before administering any drugs, fluids, or treatment to your patient, make sure you know the dose and the method.

What is the CHA2DS2-Vasc score?

The CHA2DS2-Vasc score is a medical scale used to assess the risk of ischaemic stroke and other vascular incidents (e.g., TIA - transient ischaemic attack) in patients with underlying atrial fibrillation. Atrial fibrillation is a growing medical problem that affects a large part of the population. The key to providing therapy for it is to balance two needs - to protect the patient from thromboembolic complications (by using anticoagulant therapy), and to prevent major bleedings. Luckily, to make clinical decisions easier, we have scales to help us. To assess the risk of stroke, we use CHA2DS2-Vasc, and to evaluate the risk of major bleeding, we use the HAS-BLED score.

The scale was developed in 2010 to complement the previous ruling scale - CHADS2 - with stroke risk factors, like female sex, vascular disease, and age. Since then, the American Heart Association has recommended it.

It is used mainly in patients with atrial fibrillation, but there are reports that it might be useful for other medical conditions, such as sick sinus syndrome. Also, the scale is not yet set in stone - scientific reports are trying to add obstructive sleep apnea as another major stroke risk factor to CHA2DS2-Vasc.

How to use CHA2DS2-Vasc calculator

The technical part of using our calculator is very simple - just mark all the conditions that your patient presents with a 'Yes', and your CHA2DS2-Vasc score will appear at the bottom of the calculator right away. You will also find some statistical data about the scoring and a short comment regarding anticoagulation.

When is the CHA2DS2-Vasc calculator used? It is used on every patient with atrial fibrillation before anticoagulant therapy is administered. Concomitantly, you should fill in the HAS-BLED score. You may notice that most of the stroke risk factors are major bleeding factors as well. This is why treating and controlling the factors that can be is so important.

Most of the CHA2DS2-Vasc stroke risk factors are factors for other cardiovascular diseases, as well. Check our CVD 10-year risk calculator to see if your patient has a high chance of developing one.

CHA2DS2-Vasc - stroke risk factors

There are seven significant stroke risk factors in the CHA2DS2-Vasc scale. The name of the scale is an acronym of the risks. All are worth an either 0 or 1 point, except age, which can be worth 2, and stroke, which is only worth 0 or 2.

  1. Congestive heart failure - with signs or symptoms and an objective evidence, like reduced ejection fraction (EF) during an echocardiography examination.
  2. Hypertension - defined as a blood pressure measurement >140/90mmHg on two separate occasions, or current antihypertensive treatment.
  3. Age - being older than 74 scores two points, while being between 65 - 74 years old is one point.
  4. Diabetes - defined as current use of insulin or anti-diabetic drugs, or a fasting glycemia >125mg/dL (7mmol/L). It usually goes with high values of A1c hemoglobin.
  5. Sex - female sex gives one point; however, it is valid only in the presence of at least one other stroke risk factor.
  6. Stroke - stroke, TIA (transient ischaemic attack), thromboembolism, or any other incident of cerebral ischemia in the patient's history. It adds two points to CHA2DS2-Vasc automatically - a prior incident of that kind indicates that the patient must have had some predisposing factors.
  7. Vascular disease - history of myocardial infarction, peripheral artery disease or plaque in the aorta.

CHA2DS2-Vasc risk stratification

Intuitively, the larger the patient's score in the CHA2DS2-Vasc calculator, the greater the risk of inauspicious incidents. The Swedish Atrial Fibrillation cohort study allowed us to determine precisely the risk for particular results. The researchers took into consideration not only the stroke risk but also other incidents, such as peripheral embolism or TIA - transient ischaemic attack. The CHA2DS2-Vasc risk stratification is presented in the table below.

CHA₂DS₂-VASc score Risk of ischaemic stroke (%) per one year Risk of stroke/ TIA/ peripheral embolism (%) per one year
0 0.2 0.3
1 0.6 0.9
2 2.2 2.9
3 3.2 4.6
4 4.8 6.7
5 7.2 10.0
6 9.7 13.6
7 11.2 15.7
8 10.8 15.2
9 12.23 17.4

CHA2DS2-Vasc score interpretation

Though there are seven stroke risk factors included in the CHA2DS2-Vasc scale, the recommendations divide the patients into only three groups, depending on the points scored.

Patients with 0 point, or 1 point if they are a woman, are patients with 'isolated atrial fibrillation'. They have the lowest risk of stroke. For the rest of the cases, please look at the table below.

0 points/
1 point in female
low risk groupno oral anticoagulation is suggested (!)
1 point in male moderate risk grouporal anticoagulation should be considered (!)
⩾ 2 points high risk grouporal anticoagulation is recommended

(!) - despite suggestions, clinical judgment, and individual approach should always have the last word while making medical decisions. This is crucial, especially in patients with only one stroke risk factor. All factors have a different significance, so this should be taken into account. Taking a medical history and a close examination are the best tool for any doctor in this case.

A note about confusing scale names - CHADSVasc score, CHADSVasc calculator, CHADS score

First, it's worth mentioning that the CHA2DS2-Vasc score (represented here) is built on the background of the CHADS score (or CHADS2 to be precise). CHADS score used only seven factors (congestive heart failure, hypertension, age ≥75, diabetes, prior stroke/thromboembolism/TIA), and the maximum result was 6. However, it was widely discussed and eventually qualified as 'simple, broadly applicable, but with many potential detriments'. There was a need for improvement - and so the CHA2DS2-Vasc was created.

However, many times - on the Internet, in the spoken language - you may encounter not a 'CHA2DS2-Vasc' name, but rather 'CHADSVasc calculator, CHADSVasc score'. Be aware that they all refer to the same scale, the one that you see on the screen on your left. Adding the numbers '2' to the name is meant to help doctors memorize the scale, in this case - which stroke risk factors carry two points. But in everyday life, and with tools such as Omni's CHA2DS2 Vasc calculator, you don't have to worry about those things anymore.

Aleksandra Zając, MD