Compute the Duke Treadmill Score (DTS) from a standard Bruce-protocol exercise test: exercise duration, maximal ST-segment deviation, and exercise-induced angina. Get the score, risk category, and the original study cohort's survival statistics — with a worked example.
The Duke Treadmill Score was developed by Mark DB and colleagues (N Engl J Med 1991) from 2,842 patients with known or suspected coronary artery disease who underwent Bruce-protocol exercise testing.
ST deviation carries the strongest prognostic weight (×5); the angina index is weighted ×4. Scores typically range from −25 (highest risk) to +15 (lowest risk). The worked example built into this calculator: 9 minutes, 1 mm ST deviation, angina index 1 → 9 − 5 − 4 = 0 (moderate risk).
| Score | Risk | Annual mortality* | 5-year survival* |
|---|---|---|---|
| ≥ +5 | Low | 0.25% | 97% |
| −10 to +4 | Moderate | 1.25% | 90% |
| ≤ −11 | High | 5.25% | 65% |
*From the original Mark et al. study cohort — group averages, not personal predictions. In the high-risk group, 74% of patients had 3-vessel or left main occlusive coronary disease on angiography. Fractional scores use the range rule: ≥5 → low, <−10 → high, otherwise moderate.
The Duke Treadmill Score (DTS) is a prognostic index computed from exercise treadmill test results. It was developed by Mark DB and colleagues from 2,842 patients who had exercise testing at Duke University Medical Center. It combines exercise duration, ST-segment deviation, and exercise-induced angina into one score that cardiologists use for risk stratification.
The formula is: exercise time in minutes (standard Bruce protocol) minus 5 times the maximal ST-segment deviation in millimeters, minus 4 times the treadmill angina index. Worked example: 9 minutes of exercise, 1 mm ST deviation, angina index 1 gives 9 - 5x1 - 4x1 = 0, which falls in the moderate-risk band.
A score of +5 or higher is low risk (0.25% annual mortality, 97% 5-year survival in the original study cohort). Scores from -10 to +4 are moderate risk (1.25% annual mortality, 90% 5-year survival). Scores of -11 or lower are high risk (5.25% annual mortality, 65% 5-year survival). These figures describe the original Mark et al. patient cohort — they are not a personal prediction for any individual.
Exactly +5 is the lowest score still counted as low risk, and exactly -11 is the highest score counted as high risk. For example, 5 minutes of exercise with no ST deviation and no angina gives 5 - 0 - 0 = 5, low risk; 4 minutes with the same clean test gives 4, moderate risk.
The maximal net ST-segment elevation or depression in millimeters, taken from any ECG lead except aVR during exercise. Abnormality is usually defined as 1 mm or more of horizontal or downsloping ST depression measured about 60-80 ms after the J point. At the standard ECG calibration of 10 mm per mV, 1 mm equals one small box on the ECG grid.
0 means no angina during exercise. 1 means non-limiting angina: typical chest pain occurred during exercise but the patient could continue the test. 2 means exercise-limiting angina: chest pain severe enough to stop the test.
Yes. Scores typically range from -25 (highest risk) to +15 (lowest risk). For example, 2 minutes of exercise with 3 mm ST deviation and limiting angina gives 2 - 5x3 - 4x2 = -21, high risk; 12 minutes with no ST deviation and no angina gives 12 - 0 - 0 = 12, low risk.
No. It is a risk-stratification tool that helps clinicians interpret an exercise test; it does not diagnose coronary artery disease on its own. Exercise stress testing must be performed and interpreted under medical supervision. This calculator is educational only and is not medical advice.
The score requires a standard Bruce-protocol treadmill test. It is not valid when baseline ECG abnormalities make ST criteria uninterpretable, such as left bundle branch block, a paced rhythm, Wolff-Parkinson-White pattern, or resting ST depression greater than 1 mm. It was developed in patients evaluated for suspected coronary disease, not for general fitness screening.
Those weights come from the statistical analysis in the original study: ST deviation carried the strongest prognostic weight, so it is multiplied by 5, while the angina index is multiplied by 4. They are the fitted coefficients of the study, not arbitrary choices.
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