Duke Score
Calculate the Duke Treadmill Score for cardiac risk assessment using exercise duration, ST deviation, and angina index. Get your risk category, annual mortality, and five-year survival prognosis.
About This Calculator
About the Duke Treadmill Score Calculator
The Duke Treadmill Score (DTS) is a validated clinical tool for predicting mortality and coronary artery disease (CAD) risk in patients undergoing exercise stress testing. Developed by Mark et al. in 1987 based on a study of 2,842 patients with chest pain who underwent treadmill testing and cardiac catheterization, it has become a cornerstone of cardiac risk assessment incorporated into ACC/AHA guidelines.
The score combines three key parameters from a standard Bruce protocol treadmill test: total exercise duration in minutes, maximum net ST segment deviation in millimeters (elevation or depression in any lead except aVR), and an angina index that captures symptom burden during exercise. Scores range from -25 (highest risk) to +15 (lowest risk), with risk stratified into low (score ≥5), moderate (score -10 to 4), and high (score ≤-11) categories corresponding to annual mortality rates of 0.25%, 1.25%, and 5.25% respectively.
The formula used is: Duke Treadmill Score = Exercise Duration (minutes) - (5 × ST Deviation in mm) - (4 × Angina Index), where Angina Index is 0 for no angina, 1 for non-limiting angina, or 2 for exercise-limiting angina. This weighted index helps clinicians determine whether patients with suspected coronary disease need referral for cardiac catheterization.
How This Calculator Works
Enter your exercise duration in minutes from the Bruce protocol, the maximum net ST deviation in millimeters, and select the appropriate angina index. The calculator computes the Duke Treadmill Score and provides the risk category, annual mortality rate, five-year survival prognosis, and a detailed interpretation of your results. A score breakdown chart shows how each component contributes to the final score, and a risk classification chart visualizes your risk category.
Clinical Applications
The Duke Treadmill Score is used worldwide for risk stratifying patients with suspected coronary artery disease. It helps guide clinical decisions about the need for further cardiac imaging, angiography, or medical management. High-risk patients (score ≤-11) have a 74% probability of three-vessel or left main coronary disease and require urgent evaluation. Moderate-risk patients (score -10 to 4) may benefit from additional stress imaging before deciding on invasive management.
Frequently Asked Questions
What is the Duke Treadmill Score?
The Duke Treadmill Score (DTS) is a validated prognostic tool that predicts mortality and coronary artery disease risk based on exercise stress testing. It uses exercise duration, ST segment deviation, and angina index to calculate a score ranging from -25 (highest risk) to +15 (lowest risk).
How is the Duke Treadmill Score calculated?
The Duke Treadmill Score is calculated using the formula: Exercise Time (minutes) - (5 × ST Deviation in mm) - (4 × Angina Index). The angina index is 0 for no angina, 1 for non-limiting angina, and 2 for exercise-limiting angina. The resulting score determines the risk category and prognostic outcomes.
What do the Duke Treadmill Score results mean?
Scores of 5 or higher indicate low risk (0.25% annual mortality, 97% five-year survival). Scores between -10 and 4 indicate moderate risk (1.25% annual mortality, 90% five-year survival). Scores of -11 or lower indicate high risk (5.25% annual mortality, 65% five-year survival).
Who should use the Duke Treadmill Score?
The Duke Treadmill Score is designed for patients with suspected coronary artery disease undergoing exercise stress testing. It is used by cardiologists and healthcare providers for diagnostic and prognostic assessment. Both men and women can use this score, though it may be better at excluding ischemic heart disease in women.
Can the Duke Treadmill Score replace cardiac imaging?
No. The Duke Treadmill Score is a screening and risk stratification tool. Patients with moderate or high-risk scores should be referred for additional testing such as myocardial perfusion scanning or coronary angiography. This calculator provides educational reference information and should not substitute professional medical advice.
What is the Bruce protocol used in the Duke Treadmill Score?
The Bruce protocol is a standardized treadmill exercise test protocol where both speed and grade increase every three minutes in stages. Stage 1 is 1.7 mph at 10% grade, and each subsequent stage increases speed and incline. The total exercise time in minutes measured during this protocol is used as input for the Duke Treadmill Score calculation.
How reliable is the Duke Treadmill Score for predicting outcomes?
The Duke Treadmill Score has been validated in multiple clinical studies involving thousands of patients. It is incorporated in the American College of Cardiology and American Heart Association guidelines for exercise testing. The original study found 74% of high-risk patients had three-vessel or left main coronary disease on angiography.
Is this calculator a substitute for professional medical advice?
No. This calculator is for educational and reference purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for any medical concerns or before making any decisions related to your health.