From the Guidelines
The CHA2DS2-VASc score is the most widely recommended tool to calculate ischemic risk, particularly for patients with atrial fibrillation. This scoring system assigns points for various risk factors: congestive heart failure (1 point), hypertension (1 point), age ≥75 years (2 points), diabetes (1 point), prior stroke or TIA (2 points), vascular disease (1 point), age 65-74 (1 point), and female sex (1 point) 1. The CHA2DS2-VASc score has a broader score range (0 to 9) and includes a larger number of risk factors compared to the CHA2DS2 score, making it a more comprehensive tool for assessing ischemic risk 1.
Some key points to consider when using the CHA2DS2-VASc score include:
- For patients with a score of 0 (male) or 1 (female), the risk is low enough that anticoagulation may not be necessary 1.
- For scores of 2 or higher, oral anticoagulation therapy is typically recommended 1.
- The 'C' in CHA2DS2-VASc refers to recent decompensated HF, irrespective of the ejection fraction, while 'H' refers to history of hypertension or uncontrolled BP, and 'S' refers to stroke, systemic embolism, or a confirmed diagnosis of TIA 1.
- Female sex (Sc criterion) is only relevant as a risk modifier if age > 65 or additional associated risk factors are present 1.
- Stroke risk is dynamic, and risk should be re-assessed at every patient contact, as seen in a study where the “delta CHA2DS2VASc score” was the best predictor for ischemic stroke 1.
Overall, the CHA2DS2-VASc score is a valuable tool for clinicians to make evidence-based decisions about anticoagulation therapy, balancing the risk of thromboembolism against bleeding risks, and identifying patients most likely to benefit from preventive treatments while avoiding unnecessary therapy in low-risk individuals 1.
From the Research
Ischemic Risk Score
The score used to calculate ischemic risk is not explicitly stated in the provided studies. However, various risk scores are mentioned, including:
- Framingham Risk Score (FRS) 2, 3, 4
- Prospective Cardiovascular Münster (PROCAM) risk score 5
- Systemic Coronary Evaluation (SCORE) risk chart 3
- European Society of Hypertension/European Society of Cardiology (ESH/ESC) risk chart 3
- QRISK2 4
- Joint British Society risk calculator 3 (JBS3) 4
- American College of Cardiology/American Heart Association (ACC/AHA) atherosclerotic cardiovascular disease (ASCVD) risk calculator 4
- WHO risk charts 4
Key Factors
Some key factors that are considered when calculating ischemic risk include:
- Age 5, 6
- Sex 5, 6
- LDL cholesterol 5
- HDL cholesterol 5
- Systolic blood pressure 5, 6
- Smoking status 5, 6
- Triglycerides 5
- Diabetes mellitus status 5, 6
- Body mass index (BMI) 6
- Alcohol consumption 6
- Physical activity 6
- Chronic kidney disease 6
- Family history 6
Model Performance
The performance of these risk scores and models varies, with some studies reporting: