Calculate the Duke Treadmill Score (DTS) to assess coronary artery disease risk. Enter exercise duration (minutes using Bruce protocol), maximum ST-segment deviation (mm), and angina index — and get back your Duke Treadmill Score, risk category, estimated 5-year survival rate, and annual mortality estimate.
Duke Treadmill Score
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Risk Category
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Estimated 5-Year Survival
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Estimated Annual Mortality
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The Duke Treadmill Score (DTS) is a validated prognostic tool used to estimate the risk of coronary artery disease (CAD) and predict 5-year mortality in patients undergoing treadmill ECG stress testing. It was originally developed by Mark et al. in 1987 and incorporates exercise duration, ST-segment deviation, and angina severity during exercise.
The formula is: DTS = Exercise duration (minutes) − (5 × maximum ST deviation in mm) − (4 × angina index). Exercise time is based on the Bruce protocol. The angina index is 0 for no angina, 1 for non-limiting angina, and 2 for exercise-limiting angina.
A score above 5 is low risk (approximately 97% 5-year survival). A score between −11 and 4 is intermediate risk (approximately 90% 5-year survival). A score below −11 is high risk (approximately 65% 5-year survival), with around 74% of high-risk patients having 3-vessel or left main occlusive coronary artery disease.
The Duke Treadmill Score was originally validated using the standard Bruce treadmill protocol. Exercise time entered into the formula should reflect the number of minutes completed on the Bruce protocol. Results may not be directly applicable if a different exercise protocol was used.
The ST-segment deviation refers to the maximum net ST elevation or depression observed in any electrocardiographic lead during or after exercise, excluding lead aVR. It is measured in millimeters and reflects myocardial ischemia caused by inadequate coronary blood flow during exertion.
The DTS is intended for outpatients with suspected coronary artery disease who do not have a prior known CAD diagnosis. It is not validated for patients with known prior MI, left bundle branch block, pacemakers, or those unable to complete a standard Bruce protocol stress test.
The score has been studied in women and found to have prognostic value, though some research suggests the predictive accuracy differs slightly compared to men. A study by Alexander et al. (1998) examined the value of treadmill testing specifically in women, supporting cautious application of the score in female patients.
A high-risk score (≤ −11) is associated with approximately 5.25% annual mortality. An intermediate-risk score (−10 to 4) corresponds to roughly 1.25% annual mortality. A low-risk score (≥ 5) is associated with approximately 0.25% annual mortality per year.