Determinants of exercise-induced ST segment depression in patients with coronary artery disease: A multivariate approach

The purpose of this study was to delineate among the usually gathered parameters in an electrocardiographic exercise test the determinants of its positive outcome (Delta ST down arrow greater than or equal to 1 mm measured at 80 msec from the J point). The authors studied 832 patients investigated with Bruce's exercise testing and with diagnostic coronary arteriography, all of whom were shown to have significant coronary artery disease (diameter stenosis greater than or equal to 50%). Twenty-five demographic, clinical, electrocardiographic, exercise, and anatomic/hemodynamic parameters were analyzed. The stepwise forward logistic regression analysis retained seven among them as significant independent predictors: four as positive contributors: (1) three-vessel and/or left main disease (P=0.0000), (2) Gensini's angiographic score for disease extent (P=0.0025), (3) anginal pain during the test (P=0.0000), and (4) age (P=0.0031) and three as negative contributors: (1) resting heart rate (P=0.0004), (2) history of old myocardial infarction (P=0.0019), and (3) pathological Q waves at the resting ECG (P=0.0018). These findings establish standards that permit the prediction of the positive electrocardiographic exercise outcome in patients with significant coronary disease.