Duke Treadmill Score
Why Use
Can provide diagnostic and prognostic information for patients with suspected coronary artery disease based on the treadmill exercise test.
When to Use
Patients without known coronary artery disease undergoing treadmill EKG testing.
Formula
Pearls / Pitfalls
Should be used with caution in patients undergoing testing with other protocols. If alternative protocol used, consider equivalent in multiples of resting oxygen consumption (METs) instead of minutes of exercise. Provides independent prognostic information in addition to coronary anatomy, left ventricular ejection fraction, and clinical data. Unclear utility if any of the following are present: significant valvular or congenital heart disease, previous cardiac surgery, uninterpretable EKG due to left bundle branch block, ST-segment elevation in leads with pathologic Q waves. Does not consider clinical variables such as age, heart rate, or blood pressure, which are known risk factors for CAD.
Advice
Based on score results, clinicians may decide to proceed with cardiac catheterization for suspected coronary artery disease. The 1997 ACC/AHA Guidelines for Exercise Testing and 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease state that the Duke Treadmill Score is a validated tool for risk assessment for coronary artery disease. The 1997 ACC/AHA Guidelines for Exercise Testing state if a patient has an exercise stress test with a high risk Duke Treadmill Score (<-10), coronary angiography should be considered.
More Information
Interpretation: Duke Treadmill Score Risk Group Survival at 5 Years* ≥+5 Low 99% -10 to +4 Medium 95% <-10 High 79% *For outpatients. From Mark 1991 . The data from the treadmill exercise test can be plotted on a nomogram to derive an estimate of five-year survival or average annual mortality. Prognosis is determined in five steps: The observed amount of exercise-induced ST-segment deviation (the largest elevation or depression after resting changes have been subtracted) is marked on the line for ST-segment deviation during exercise. The observed degree of angina during exercise is marked on the line for angina. The marks for ST-segment deviation and degree of angina are connected with a straight edge. The point where this line intersects the ischemia-reading line is noted. The total number of minutes of exercise in treadmill testing according to the Bruce protocol (or the equivalent in multiples of resting oxygen consumption [METs] from an alternative protocol) is marked on the exercise-duration line. The mark for ischemia is connected with that for exercise duration. The point at which this line intersects the line for prognosis indicates the five-year survival rate and average annual mortality for patients with these characteristics.