The Duke Treadmill Score (DTS) is a point system to predict 5-year mortality based on treadmill ECG stress testing in patients without known coronary artery disease. The Duke Treadmill Score is calculated as below:
DTS = Exercise time (minutes) - (5 x ST deviation in mm) - (4 x angina index)
The exercise time is based on using the standard Bruce protocol.
ST deviation refers to maximum ST change (elevation or depression) in any lead except lead aVR.
The angina index gives 0 points if no angina occurs, 1 point if non-limiting angina occurs and 2 points if angina occurs which limits exercise.
Patients are categorized as low-, intermediate- or high-risk.
Low risk (score > 5) indicates a 5-year survival of 97%.
Intermediate risk (score between 4 and -11) indicates 5-year survival of 90%.
High risk (score < -11) indicates 5-year survival of 65%.
In high-risk patients, 74% had 3-vessel or left main occlusive coronary disease on angiography.