Calculate the Duke Treadmill Score from exercise stress test results. Estimates annual cardiac mortality risk and guides need for coronary angiography.
The Duke Treadmill Score (DTS) Calculator interprets exercise stress test results and places the patient into low, moderate, or high cardiac risk groups. It combines exercise time, ST-segment deviation, and exercise-related angina into a single score.
Low scores point toward higher risk, while higher scores are more reassuring. The result is most useful when it is read alongside the exercise report and the patient's overall clinical picture.
Use the Duke Treadmill Score to turn stress-test findings into a clearer risk estimate. It helps show when the test is reassuring and when further evaluation may be worth considering.
The score is especially useful when the exercise ECG findings need to be summarized for follow-up decisions or referral.
Duke Treadmill Score = Exercise Time (minutes) − (5 × max ST deviation in mm) − (4 × Angina Index) Angina Index: 0 = no angina; 1 = non-limiting angina; 2 = exercise-limiting angina Low Risk: DTS ≥ +5 (annual mortality <1%) Moderate Risk: DTS −10 to +4 (annual mortality 2-3%) High Risk: DTS < −10 (annual mortality ≥5%)
Result: DTS = 2 — Moderate Risk (2-3% annual mortality)
DTS = 7 min − (5 × 1 mm) − (4 × 0) = 7 − 5 − 0 = 2. A score between −10 and +4 indicates moderate risk with approximately 2-3% annual cardiac mortality. Further non-invasive imaging or clinical correlation is recommended.
The DTS has been validated in over 10,000 patients across multiple institutions. In the original Duke cohort, the score correctly stratified patients into risk categories with 5-year survival of 97% (low risk), 90% (moderate), and 75% (high risk). The score performs best in intermediate pre-test probability populations.
Additional exercise test features provide prognostic information: exercise-induced ventricular arrhythmias, abnormal heart rate recovery (failure to decrease >12 bpm in the first minute post-exercise), and abnormal blood pressure response. Integrating these with the DTS provides more refined risk assessment.
Stress echocardiography and nuclear perfusion imaging provide functional and anatomic information beyond exercise ECG. CT coronary angiography offers direct anatomic visualization. However, the standard exercise test with DTS calculation remains a cost-effective first-line evaluation for patients capable of adequate exercise.
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This calculator applies the standard Duke Treadmill Score equation by combining exercise duration, maximal ST-segment deviation, and angina during exercise into the familiar low-, intermediate-, and high-risk bands. The output is meant to summarize the prognostic signal from a standard exercise ECG stress test rather than to replace the full stress-test report.
The score is most defensible in patients who complete an interpretable exercise ECG test. Baseline ECG abnormalities, submaximal effort, non-treadmill protocols, and the broader clinical context can all change how the result should be used, so the page should be treated as a risk-summary aid rather than a catheterization rule by itself.
The original DTS was derived predominantly from male populations. While it has been validated in women, exercise ECG testing has lower sensitivity and specificity in women due to hormonal effects on ST segments. Some experts recommend stress imaging over exercise ECG alone for women.
A submaximal test is less reassuring. The DTS can still be calculated, but the result should be interpreted more cautiously and alongside the reason the target was not reached.
No. Baseline ST abnormalities (LVH, digoxin, LBBB) reduce the diagnostic value of exercise ST changes. The DTS should be interpreted cautiously in these patients, and stress imaging is preferred.
Exercise capacity (METs) is one of the strongest predictors of all-cause mortality, independent of other factors. Patients achieving <5 METs have significantly worse prognosis. Each 1-MET increase in capacity is associated with 10-15% reduction in mortality.
A low score may not need more testing, a moderate score often leads to stress imaging, and a high score may lead to angiography depending on the rest of the case.
Chronotropic incompetence is the inability to achieve 85% of age-predicted max HR despite adequate effort (in the absence of beta-blockers or rate-limiting medications). It is an independent predictor of cardiac events and all-cause mortality.