Turns a Bruce protocol exercise test into a prognostic score from exercise time, ST deviation and angina.
Result
Enter the exercise time, ST deviation and angina during the test.
Sources
ACC/AHA 2002 · 5 studies
ACC/AHA 2002 Exercise testing to estimate prognosis; presents the Duke treadmill score as a validated tool.
5
studies
661
citations
162
PubMed papers
Evidence
Guideline recommendation
“The ACC/AHA 2002 exercise testing guideline update recommends using exercise test results to estimate prognosis, and presents the Duke treadmill score, with its low, moderate and high risk groups, as a validated way of doing so in patients with suspected or known coronary disease.”
American College of Cardiology / American Heart Association
Circulation: Journal Metrics Score 2.3, Q2 · cited 2,591 times
Known limitations
Of 2,842 inpatients, 13% were high risk, 53% moderate and 34% low. Among patients with three-vessel disease, 5-year survival was 67% with a score of −11 or less and 93% with +7 or more.
Ann Intern Med: Journal Metrics Score 4.6, Q1 · cited 661 times
In 613 outpatients, about two thirds scored +5 or more and had 99% 4-year survival (0.25% a year); 4% scored below −10 and had 79% 4-year survival (5% a year). The area under the curve for death was 0.849.
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 836 times
The score also predicted the extent of coronary disease in patients referred for catheterization: 60% of low-risk patients (+5 or more) had no stenosis of 75% or more, while 74% of high-risk patients (defined in this study as below −11) had three-vessel or left main disease. Five-year mortality was 3%, 10% and 35% in the low, moderate and high groups.
Circulation: Journal Metrics Score 2.3, Q2 · cited 309 times
In older patients the score predicted cardiac survival in younger age groups but not in those aged 75 or over, most of whom were classed as moderate risk; even the low-risk group had an annual cardiac mortality of about 2%.
J Am Coll Cardiol: Journal Metrics Score 1.2, Q3 · cited 95 times
In 976 women and 2,249 men, the score stratified survival equally well in both sexes; low-risk women had less significant coronary disease than low-risk men (20% vs 47%).
J Am Coll Cardiol: Journal Metrics Score 1.2, Q3 · cited 232 times
The original paper has been cited 661 times, and 162 PubMed articles mention the Duke treadmill score in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 14, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
High risk (below −10) · Moderate risk (−10 to +4) · Low risk (+5 or more)
Coronary angiography. Further testing. Medical management.
Next steps
Avoid common errors
6 common errors to avoid
and 4 more
When the score misleads
1Uninterpretable resting ECG
Left bundle branch block, pacing, pre-excitation, more than 1 mm resting ST depression and digoxin make exercise ST changes unreadable; use stress imaging instead (vasodilator stress perfusion imaging with left bundle branch block or pacing).
2Bruce protocol only
Minutes on other protocols do not equal Bruce minutes; the score was not validated on them.
3Prognosis, not diagnosis
A low score means a low risk of death; it does not exclude coronary disease, and some low-risk patients have significant stenoses.
4Stopping early
A test stopped for reasons other than angina (fatigue, breathlessness, blood pressure, arrhythmia) still scores the time achieved; record why it stopped.
5Older patients
In patients aged 75 or over the score did not predict cardiac survival: most were classed as moderate risk, and even low-risk patients had about 2% cardiac mortality a year (Kwok 2002). Interpret it cautiously in this age group.
6Other high-risk findings
A fall in systolic blood pressure during exercise, sustained ventricular tachycardia, ST elevation in leads without Q waves, or marked ST depression at a low workload or persisting late into recovery call for further evaluation whatever the score.
Formula
Minutes on the Bruce protocol − 5 × ST deviation (mm) − 4 × angina index; +5 or more low, below −10 high.
min − 5×ST − 4×angina
Minutes on the Bruce protocol − 5 × ST deviation (mm) − 4 × angina index; +5 or more low, below −10 high.
Components and risk groups
| Component | Contribution |
|---|---|
| Exercise time | + minutes completed on the Bruce protocol |
| ST deviation | − 5 × largest net ST deviation in mm (any lead except aVR, exercise or recovery) |
| Angina index | − 4 × 0: no angina during the test− 4 × 1: angina, but not the reason for stopping− 4 × 2: angina that stopped the test |
| Risk | Score | Outpatients | 4-year survival | 5-year mortality |
|---|---|---|---|---|
| Low risk | +5 or more | 62% | 99% (0.25%/yr) | 3% |
| Moderate risk | −10 to below +5 | 34% | 95% (1.25%/yr) | 10% |
| High risk | below −10 | 4% | 79% (5%/yr) | 35% |
Mark 1987
Mark 1991
Cut-offs
Test cases
3 published cases, each also a test case
3 published cases; the calculator reproduces every score.
Worked examples
A 53-year-old man had chest pain at night and a troponin rise (NSTEMI); angiography showed severe myocardial bridging without obstructive coronary disease, and he was treated with a beta-blocker. A treadmill test on day 6 lasted 12 minutes without chest pain or ischemic ECG changes, and the report gives a Duke treadmill score of 12.
“Duke treadmill score of 12, explained by 12 minutes of exercise”
At one year a repeat test gave 6.4 after 11.4 minutes. The report describes ST deviation under 1 mm, read as a normal response, but the reported score corresponds to 1 mm being entered (11.4 − 5 × 1 = 6.4). Both are low risk.
Entered as: Exercise time (Bruce protocol): 12 minutes; Maximal ST deviation: 0 mm; Treadmill angina index: No angina during the test (0).
Source: Bettinotti BG et al., Cureus 2026 (PubMed · Free full text · DOI)
A woman with a year of chest discomfort and near-fainting was admitted after a syncopal episode. Her treadmill test was stopped after 6 minutes for fatigue, without symptoms, with 1.5 mm ST depression in the inferior and lateral leads that resolved quickly in recovery; the report gives a Duke treadmill score of −1.5. Coronary CT showed only mild disease; an ambulatory ECG later caught ST elevation with non-sustained ventricular tachycardia, and invasive angiography then showed right coronary spasm that resolved with nitroglycerin.
“Her calculated Duke Treadmill Score was −1.5.”
The report does not name the protocol; 7.2 METs at 6 minutes is consistent with the Bruce protocol. Moderate risk. The score assesses fixed coronary stenosis on exertion; it says nothing about vasospasm, which often strikes at rest.
Entered as: Exercise time (Bruce protocol): 6 minutes; Maximal ST deviation: 1.5 mm; Treadmill angina index: No angina during the test (0).
Source: Shtembari J et al., HeartRhythm Case Rep 2026 (PubMed · Free full text · DOI)
A 73-year-old man had two weeks of exertional chest pain and breathlessness. He exercised for 4 minutes on the Bruce protocol before chest pain and breathlessness stopped the test, with more than 1 mm of horizontal ST depression in the inferior and anterior leads; the authors give a Duke treadmill score of −11.5. The perfusion scan showed no ischemia (only a small fixed defect in the basal inferior segment), but angiography showed severe three-vessel disease (balanced ischemia).
“which makes a duke treadmill score of -11.5”
The report says only that the ST depression was more than 1 mm; 1.5 mm is back-calculated from the reported score (4 − 5 × 1.5 − 4 × 2 = −11.5). The ST elevation in aVR, also reported, is not counted. High risk, matching the three-vessel disease found at angiography.
Entered as: Exercise time (Bruce protocol): 4 minutes; Maximal ST deviation: 1.5 mm; Treadmill angina index: Angina that stopped the test (2).
Source: Baqi A et al., Cureus 2020 (PubMed · Free full text · DOI)
FAQ
6 questions and answers
and 4 more answers
Questions
Exercise time in minutes on the Bruce protocol, minus 5 × the largest ST deviation in millimetres, minus 4 × the angina index (0 no angina, 1 angina that did not stop the test, 2 angina that stopped it). Nine minutes with 1 mm of ST depression and non-limiting angina gives 9 − 5 − 4 = 0.
+5 or more is low risk: in the outpatient validation study 99% of these patients were alive at 4 years. −10 to +4 is moderate risk and below −10 high risk, with 4-year survival of 79% in the high-risk group.
The largest net ST-segment deviation, depression or elevation, in any lead except aVR, during exercise or recovery, in millimetres. Enter 0 if there was none. Some laboratories count deviation under 1 mm as 0, since it is usually read as normal.
The score was developed and validated with the Bruce protocol. Exercise time on other protocols is not equivalent; some laboratories convert the workload to an equivalent Bruce time, but that has not been validated in the same way.
Yes. In 976 women and 2,249 men who had both treadmill testing and angiography, the score stratified prognosis equally well in both, and low-risk women were less likely than low-risk men to have significant coronary disease.
When the resting ECG makes exercise ST changes unreadable: left bundle branch block, a paced rhythm, pre-excitation (Wolff–Parkinson–White), more than 1 mm of resting ST depression, or digoxin. Left ventricular hypertrophy with repolarisation changes also reduces accuracy. These patients need stress imaging; with left bundle branch block or a paced rhythm, vasodilator stress perfusion imaging is preferred to exercise imaging.
Further reading
9 references with PubMed and DOI links
9
references
3
free full text
From Mark DB et al., Ann Intern Med 1987 to the newest case reports.
References
clinical grade of aneurysmal subarachnoid hemorrhage, I to V.
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MAP from systolic and diastolic pressure, against the 65 mm Hg target.
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oxygenation ratio with the Berlin ARDS severity ranges.
serum sodium corrected for high glucose, Katz or Hillier factor.
sodium − (chloride + bicarbonate), with the albumin-corrected gap.
urea nitrogen to creatinine ratio, in US or SI units.
estimated creatinine clearance with actual, ideal or adjusted weight.
cardiac output and index from oxygen consumption and saturations.
ANC from the white cell count, neutrophils and bands.
insulin resistance from fasting glucose and insulin, in US or SI units.
FENa from plasma and urine sodium and creatinine: prerenal, indeterminate or tubular pattern.
three-item stroke severity screen for large vessel occlusion, 0 to 4.
water deficit in hypernatremia from sodium, weight and body water.
expected PaCO2 in metabolic acidosis, 1.5 × HCO3 + 8 ± 2.
corrected QT interval by Bazett, Fridericia, Framingham or Hodges.
head CT decision rule for children with minor head trauma.
blood loss before hemoglobin or hematocrit reaches a chosen lowest value.
eye, verbal and motor response, 3 to 15, with GCS-Pupils.
Devine ideal body weight and adjusted weight from height and sex.
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MELD, MELD-Na and MELD 3.0 for chronic liver disease.
early stroke risk after a transient ischemic attack.
whether a patient with blunt trauma needs cervical spine imaging.
alveolar–arterial oxygen gradient from a blood gas.
whether an adult with minor head injury needs CT.
risk of advanced liver fibrosis from age, AST, ALT and platelets.
Which published the original score, with its current metrics.
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 14, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.