Free Duke Treadmill Score Calculator

What Is Duke Treadmill Score?

The Duke Treadmill Score (DTS) is a widely used risk‑stratification index that combines three variables from the standard Bruce‑protocol treadmill exercise test: exercise duration, maximal net ST‑segment deviation, and an exercise‑induced angina index. This score helps predict the probability of coronary artery disease (CAD) and future cardiac events, making it a valuable coronary artery disease risk assessment tool. This free Duke Score Calculator allows clinicians and individuals to quickly perform cardiac risk calculation based on stress test data, without the need for complex manual computation.

The Role of Exercise Stress Testing in CAD

Coronary artery disease occurs when atherosclerotic plaque narrows the arteries supplying the heart. As the most prevalent form of heart disease, CAD can manifest as angina, heart failure, or even sudden heart attack. Exercise stress testing is a standard diagnostic procedure that monitors the heart's electrical activity and symptoms while the patient walks on a treadmill. The Duke Treadmill Score quantifies the test results to stratify risk and guide further management.

How the Duke Treadmill Score Is Calculated

The DTS formula is:

$$\text{DTS} = \text{Exercise Duration (min)} - 5 \times \text{ST Deviation (mm)} - 4 \times \text{TAI}$$

• Exercise Duration: Total minutes the patient exercised following the Bruce protocol. This reflects functional capacity.
• ST‑segment Deviation: The maximal net ST deviation (elevation or depression) in millimeters, excluding lead aVR. Larger values indicate more significant myocardial ischemia.
• Treadmill Angina Index (TAI): A graded score for chest pain experienced during the test:

Angina Description	TAI Score
No angina or pain	0
Typical angina that does not force test termination	1
Exercise stopped because of angina	2

The typical DTS range is from –25 (worst prognosis) to +15 (best prognosis). Each component captures a different aspect of the cardiac response: duration reflects reserve, ST deviation points to ischemia, and the angina index incorporates symptom burden.

Risk Classification and Prognostic Value

Patients are categorized into three groups based on their DTS:

DTS Range	Risk Group	4‑Year Survival
≥ 5	Low	99%
–10 to +4	Medium	95%
< –10	High	79%

A higher score corresponds to a better outlook. Those in the high‑risk group often require further investigation or aggressive treatment.

Practical Example

Consider a patient named Susan who exercises for 8 minutes without experiencing any angina. Her maximal ST‑segment deviation is 0.6 mm. The calculation proceeds as:

$$\text{DTS} = 8 - (5 \times 0.6) - (4 \times 0) = 8 - 3 = 5$$

With a DTS of 5, Susan falls into the low‑risk category, indicating an excellent 4‑year survival prognosis. This example shows how easily the exercise stress test score can be converted into actionable clinical information.

Important Disclaimer

This free Duke Treadmill Score calculator is intended for educational and informational purposes. It does not replace professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment decisions.