Identifying priority patients for coronary angiography

We conducted an open observational study with blinded endpoint evaluation to validate the use of the Duke treadmill score in identifying patients likely to require coronary intervention. We studied 101 consecutive patients referred for coronary angiography from a cardiology clinic. All patients had a Bruce protocol exercise test. A 70% stenosis was regarded as significant. Patients were referred for percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) surgery, if indicated. The Duke score was calculated as follows: exercise time (min) - (5 x ST segment deviation mm]) - (4 x angina index text]). Patients were classified into low, medium and high risk. The patients at high risk are more likely to have a significant stenosis (53/58 vs 30/43: p = 0.01 OR 4.59 95% CI 1.34-16.6]) and require CABG or PTCA (47/58 vs 16/43: p < 0.001 OR 7.21 95% CI 2.69-19.8]) than those at medium/low risk. Multiple logistic regression analysis, including ST segment depression, exercise time and symptoms shows that the score independently predicts a significant stenosis (p = 0.002) and the need for coronary intervention (p = 0.001). Introducing the score can help to identify those patients who need priority investigation.