The CHADSVASC score (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes, prior Stroke/TIA, Vascular disease, Age 65–74 years, and Sex category [female]) is a clinical tool used to assess the risk of thromboembolic events, such as stroke, in patients with non-valvular atrial fibrillation (NVAF). It is a simple, validated risk stratification system that helps clinicians make informed decisions about anticoagulation therapy.
How the CHADSVASC Score is Calculated
The score is derived from a patient's medical history and demographic factors. Each risk factor contributes points to the total score. Here's a breakdown of how each component is weighted:
Congestive Heart Failure: 1 point
Hypertension: 1 point
Age ≥75 Years: 2 points
Diabetes Mellitus: 1 point
Prior Stroke or Transient Ischemic Attack (TIA): 2 points
Vascular Disease (history of myocardial infarction, peripheral arterial disease, or aortic plaque): 1 point
Age 65–74 Years: 1 point
Sex Category (Female): 1 point
Note: Patients with NVAF are assumed to have an underlying risk, and the score is calculated based on the presence of these additional risk factors. The calculator above simplifies the scoring by directly asking for the presence of each factor and applying the correct points. For instance, "History of Stroke or Transient Ischemic Attack (TIA)" directly adds 2 points if "Yes" is selected. Similarly, "Age (Years)" contributes points based on the thresholds: 1 point if the age is between 65 and 74, and 2 points if the age is 75 or older. The 'Sex' input assigns 1 point if 'Female' is selected.
Interpreting the CHADSVASC Score
The total score helps predict the annual risk of stroke or systemic embolism:
Score 0: Approximately 0% annual risk
Score 1: Approximately 1.3% annual risk
Score 2: Approximately 2.2% annual risk
Score 3: Approximately 3.2% annual risk
Score 4: Approximately 4.0% annual risk
Score 5: Approximately 4.3% annual risk
Score 6+: Approximately 4.9% annual risk
Generally, patients with a CHADSVASC score of 2 or higher in men, or 3 or higher in women, are considered to be at increased risk and are typically recommended for oral anticoagulation therapy (e.g., warfarin, DOACs) to prevent stroke. Patients with a score of 1 may be considered for anticoagulation, but the decision is often individualized. A score of 0 usually indicates a very low risk, and anticoagulation may not be necessary.
Importance in Clinical Practice
The CHADSVASC score is a crucial tool in managing atrial fibrillation. It provides a standardized and evidence-based approach to risk assessment, helping to balance the benefits of stroke prevention with the risks of bleeding associated with anticoagulation. Regular reassessment of the score may be necessary as a patient's clinical status changes.
function calculateChadsvasc() {
var age = parseFloat(document.getElementById("age").value);
var hypertension = parseInt(document.getElementById("hypertension").value);
var antiplatelet = parseInt(document.getElementById("antiplatelet").value); // Note: Antiplatelet therapy is NOT part of original CHADSVASC, but is often considered in risk assessment, especially in stroke prevention guidelines. For this calculator, we will exclude it from the core CHADSVASC score calculation to adhere to the standard but mention its relevance.
var diabetes = parseInt(document.getElementById("diabetes").value);
var stroke_tia = parseInt(document.getElementById("stroke_tia").value);
var vascular = parseInt(document.getElementById("vascular").value);
var sex = parseInt(document.getElementById("sex").value); // 0 for Female, 1 for Male
var score = 0;
var riskFactors = [];
// Age
if (age >= 75) {
score += 2;
riskFactors.push("Age ≥75 years (2 points)");
} else if (age >= 65 && age 0) {
resultHTML += "Contributing Factors:";
resultHTML += "
";
for (var i = 0; i < riskFactors.length; i++) {
resultHTML += "
" + riskFactors[i] + "
";
}
resultHTML += "
";
}
// Interpretation based on score
var interpretation = "";
if (score === 0) {
interpretation = "Annual stroke risk is very low (approx. 0%). Anticoagulation is generally not indicated.";
} else if (score === 1) {
interpretation = "Annual stroke risk is low (approx. 1.3%). Anticoagulation may be considered based on individual assessment.";
} else if (score === 2) {
interpretation = "Annual stroke risk is moderate (approx. 2.2%). Anticoagulation is generally recommended.";
} else { // score >= 3
interpretation = "Annual stroke risk is significant (approx. 3.2% or higher). Anticoagulation is strongly recommended.";
}
resultHTML += "" + interpretation + "";
resultDiv.innerHTML = resultHTML;
}