Cardiopulmonary Function Assessment Scores (CPET)

Duke Treadmill Score (DTS) with Bruce protocol Calculator

Clinical calculation support · Verify results before clinical use

Calculate the score

Enter exercise duration, maximal net ST-segment deviation, and exercise-related angina using the original Duke Treadmill Score definitions.

DTSRisk score

Exercise duration

Total exercise time achieved on the Bruce treadmill protocol. Enter minutes as a decimal, e.g. 7.5.

Unit: minutes

Maximal net ST-segment deviation

Enter the magnitude in millimeters as assessed during or after exercise. Use the value determined from the exercise ECG report.

Unit: mm

Angina during exercise

Select the symptom category that best matches the test.

None0 points · No angina during exercise

Non-limiting angina1 point · Angina occurs but does not limit exercise

Exercise-limiting angina2 points · Angina is the reason exercise stops

About the Duke Treadmill Score

The Duke Treadmill Score (DTS) combines exercise duration, maximal net ST-segment deviation, and exercise-related angina to stratify prognosis in adults undergoing exercise treadmill testing for suspected coronary artery disease. The original score was developed using exercise testing performed with the Bruce protocol.

Formula

Duke Treadmill Score	Exercise duration (min) − 5 × ST deviation (mm) − 4 × angina index
Angina index 0	No angina during exercise
Angina index 1	Non-limiting angina
Angina index 2	Exercise-limiting angina

Risk categories

DTS	Category	Published outpatient cohort
≥ +5	Low risk	Approximately 99% 4-year survival
≥ −10 and < +5	Intermediate risk	Approximately 95% 4-year survival
< −10	High risk	Approximately 79% 4-year survival

Survival estimates above are from the outpatient cohort reported by Mark and colleagues in 1991. Estimates differed in the original referred inpatient cohort; they are population-level historical results, not guaranteed outcomes for an individual patient.

Important limitations

Use the score as one component of clinical assessment, not as a standalone diagnosis of obstructive coronary artery disease.
Interpretation may be limited when the resting ECG is not suitable for ischemia assessment, exercise is submaximal, or the test is otherwise nondiagnostic.
Consider symptoms, pre-test likelihood, exercise capacity, hemodynamic response, ECG quality, comorbidities, and applicable local guidelines.

References

Mark DB, Hlatky MA, Harrell FE Jr, Lee KL, Califf RM, Pryor DB. Exercise treadmill score for predicting prognosis in coronary artery disease. Ann Intern Med. 1987;106(6):793–800. DOI: 10.7326/0003-4819-106-6-793; PMID: 3579066.

Mark DB, Shaw L, Harrell FE Jr, et al. Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease. N Engl J Med. 1991;325:849–853. DOI: 10.1056/NEJM199109193251204; PMID: 1875969.

Interpreting exercise treadmill tests needs scoring system. BMJ. 2002;325:522. Available at: PubMed Central.

Clinical disclaimer: This calculator is intended to support clinical assessment and education. The score does not replace clinician interpretation of the complete exercise test or current guideline-based decision-making. Historical survival estimates vary by cohort and should not be presented as individualized predictions. Urgent symptoms or clinical instability require assessment regardless of the calculated score.