Healthcare & Clinical
Duke Treadmill Score (DTS): Bruce Protocol Exercise Stress Test Prognosis
Calculate Mark's Duke Treadmill Score DTS = Exercise_Minutes - (5 * Max_ST_Deviation_mm) - (4 * Treadmill_Angina_Index) to stratify 1-year and 5-year coronary mortality into Low (>= +5), Moderate (-10 to +4), and High (<= -11) risk.
Combine Bruce exercise duration, ST depression, and limiting angina into one prognostic score!
Reading an exercise ECG as simply "positive or negative for 1 mm ST depression" ignores functional exercise capacity and whether chest pain forced test termination! Daniel Mark et al. at Duke University derived the validated Bruce-protocol Duke Treadmill Score: DTS = Exercise_Time_Minutes - (5 * Max_Net_ST_Deviation_mm) - (4 * Angina_Index), where Angina_Index is 0 = no angina during exercise, 1 = non-limiting angina, and 2 = exercise-limiting angina (angina was the reason for stopping the treadmill)!
DTS stratifies outpatient annual cardiovascular mortality cleanly across three ACC/AHA tiers: Low Risk DTS >= +5 (~0.25% annual mortality, ~97%+ 5-year survival -> medical management), Moderate Risk -10 <= DTS < +5 (~1.25% annual mortality -> stress imaging / coronary CTA), and High Risk DTS <= -11 (~5.0%+ annual mortality, high prevalence of left-main or 3-vessel CAD -> invasive coronary angiography)!
| Bruce Treadmill Test Result | DTS Calculation | Duke Treadmill Score | ACC/AHA Risk Tier |
|---|---|---|---|
| 10.0 min, 0 mm ST, No Angina (0) | 10.0 - 0 - 0 | +10.0 (>= +5) | Low Risk (~0.25%/yr mortality) |
| 9.5 min, 1.5 mm ST, Non-Limiting Angina (1) | 9.5 - 7.5 - 4.0 | -2.0 (-10 to +4) | Moderate Risk (~1.25%/yr mortality) |
| 5.0 min, 2.5 mm ST, Limiting Angina (2) | 5.0 - 12.5 - 8.0 | -15.5 (<= -11) | High Risk (~5%/yr: Cath Evaluation!) |
Duke Treadmill Score DTS = Minutes - (5 * ST_mm) - (4 * Angina_0_1_2)
Validates positive Bruce exercise minutes B2, non-negative ST deviation B3, and Angina_Index B4 in {0, 1, 2}.
=IF(OR(B2 <= 0, B3 < 0, B4 < 0, B4 > 2, B4 <> INT(B4)), "Invalid Stress Test Inputs", ROUND(B2 - (5 * B3) - (4 * B4), 1))ACC/AHA Duke Treadmill Prognostic Risk Stratum
Classifies DTS into Low (>= 5), Moderate (> -11 and < 5), or High (<= -11) coronary risk.
=IF((B2 - (5 * B3) - (4 * B4)) >= 5, "Low Risk (DTS >= +5: ~0.25%/yr Mortality)", IF((B2 - (5 * B3) - (4 * B4)) <= -11, "High Risk (DTS <= -11: ~5%/yr Mortality)", "Moderate Risk (-10 to +4: ~1.25%/yr Mortality)"))Try the example
Use the original values or change them to test your understanding.