DTS = Exercise time (minutes) − (5 × ST deviation in mm) − (4 × Angina Index). Angina index: 0 = no angina, 1 = non-limiting angina, 2 = exercise-limiting angina. For example, 8 minutes exercise, 2 mm ST depression, non-limiting angina: 8 − (5×2) − (4×1) = −6 (moderate risk).

Low risk (DTS ≥5): Annual mortality <1%, 5-year survival 97%. Usually no additional workup needed. Moderate risk (DTS −10 to +4): Annual mortality 2–3%. Consider additional imaging. High risk (DTS < −10): Annual mortality ≥5%. Coronary angiography recommended.

The Bruce protocol is the standard treadmill protocol used in exercise stress testing. It starts at 1.7 mph / 10% grade and increases speed and grade every 3 minutes through 7 stages. Average healthy adults complete 8–12 minutes. Exercise capacity (METs achieved) is itself a strong predictor of mortality.