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Duke Treadmill Score Calculator

Free Duke treadmill score Calculator with medically-sourced formulas. Enter your measurements for personalized, accurate health insights.

Reviewed by Rahul Singh, Health & Wellness Specialist

Reviewed by Rahul Singh, Health & Wellness Specialist

Formula

DTS = Exercise time (min) - (5 x ST deviation mm) - (4 x Angina index)

Where DTS = Duke Treadmill Score, Exercise time is measured in minutes on the Bruce protocol, ST deviation is the maximum ST-segment depression or elevation in mm, and Angina index is 0 (no angina), 1 (non-limiting angina), or 2 (exercise-limiting angina). Score >= 5 is low risk, -10 to +4 is intermediate risk, and < -10 is high risk.

Worked Examples

Example 1: Low Risk Score

Problem:A patient exercises for 9 minutes on the Bruce protocol, develops 0.5 mm ST depression, and has no chest pain during the test.

Solution:DTS = Exercise time - (5 x ST deviation) - (4 x Angina index)\nDTS = 9 - (5 x 0.5) - (4 x 0)\nDTS = 9 - 2.5 - 0 = 6.5\nScore >= 5: Low Risk\nEstimated annual mortality: < 1%\n5-year survival: > 97%

Result:Duke Treadmill Score: 6.5 (Low Risk - Medical therapy appropriate)

Example 2: High Risk Score

Problem:A patient exercises for only 4 minutes on the Bruce protocol, develops 3 mm ST depression, and has exercise-limiting angina requiring test termination.

Solution:DTS = Exercise time - (5 x ST deviation) - (4 x Angina index)\nDTS = 4 - (5 x 3) - (4 x 2)\nDTS = 4 - 15 - 8 = -19\nScore < -10: High Risk\nEstimated annual mortality: > 3%\n5-year survival: < 85%

Result:Duke Treadmill Score: -19 (High Risk - Coronary angiography recommended)

Frequently Asked Questions

What is the Duke Treadmill Score and what does it predict?

The Duke Treadmill Score (DTS) is a validated prognostic tool derived from exercise treadmill testing that predicts cardiovascular mortality and identifies patients who may benefit from coronary angiography and potential revascularization. Developed by Mark and colleagues at Duke University Medical Center in 1987 from a cohort of 2,842 consecutive patients, the score combines three key exercise test parameters: exercise duration (in minutes on the Bruce protocol), maximum ST-segment deviation (in millimeters), and the presence and severity of exercise-induced angina. The score ranges from approximately -25 (worst prognosis) to +15 (best prognosis) and categorizes patients into low-risk (5 or higher), intermediate-risk (-10 to +4), and high-risk (below -10) groups with distinct survival curves.

How is the Duke Treadmill Score calculated?

The Duke Treadmill Score is calculated using a simple formula: DTS equals exercise time in minutes minus 5 multiplied by the maximum ST-segment deviation in millimeters, minus 4 multiplied by the angina index. Exercise time is measured during the Bruce treadmill protocol, where each stage lasts 3 minutes with increasing speed and incline. The ST-segment deviation is the maximum deviation observed in any lead during exercise or recovery, measured in millimeters from the baseline. The angina index is scored as 0 for no angina during the test, 1 for non-limiting angina (angina that occurs but does not require test termination), and 2 for exercise-limiting angina (angina that is the reason for stopping the test). Each component contributes independently to the prognostic assessment.

What do the risk categories of the Duke Treadmill Score mean clinically?

The three risk categories have distinct clinical implications for patient management. Low-risk patients (score 5 or higher) comprise approximately 60 percent of tested patients and have an annual mortality rate of less than 1 percent and 5-year survival exceeding 97 percent. These patients generally do well with medical therapy alone and typically do not require invasive evaluation. Intermediate-risk patients (score -10 to +4) represent about 30 percent of patients and have annual mortality of 1 to 3 percent. These patients often benefit from additional non-invasive testing such as stress echocardiography or nuclear perfusion imaging to better define their risk. High-risk patients (score below -10) constitute approximately 10 percent of patients and have annual mortality exceeding 3 percent with 5-year survival below 85 percent. These patients are generally referred directly for coronary angiography.

How significant is ST-segment deviation in the Duke Treadmill Score?

ST-segment deviation is the most heavily weighted component in the Duke Treadmill Score, multiplied by a factor of 5. This reflects the strong association between the degree of ST-segment change during exercise and the presence and severity of coronary artery disease. ST-segment depression of 1 mm or more (measured 60 to 80 milliseconds after the J-point) is considered a positive test result. Greater degrees of ST depression correlate with more extensive coronary disease and worse prognosis. ST depression of 2 mm or more is particularly concerning and associated with multivessel or left main coronary disease. The timing and morphology of ST changes also matter clinically: early onset during exercise, persistence into recovery, and downsloping morphology are all more concerning features. ST-segment elevation (except in aVR or leads with Q waves) during exercise suggests transmural ischemia and localizes the area of jeopardized myocardium.

References

Reviewed by Rahul Singh, Health & Wellness Specialist · Editorial policy