Identification of severe coronary artery disease using simple clinical parameters.

The purpose of our study was to examine the ability of clinical and resting electrocardiographic variables to provide useful estimates of the probability of three-vessel or left-main coronary artery disease. The study group consisted of 680 patients with symptomatic coronary artery disease who underwent exercise equilibrium radionuclide angiography and coronary angiography within 6 months. Sixteen clinical and electrocardiographic variables were examined by logistic regression analysis. The independently predictive variables were then used to develop convenient graphic estimates of the probability of three-vessel or left-main disease and to classify patients into high-risk (greater than 35%), intermediate-risk (15-35%), or low-risk (less than 15%) groups. Five variables were independently predictive of left-main or three-vessel disease: age, typical angina, diabetes, gender, and both history and electrocardiographic evidence of a prior myocardial infarction. A single graph was constructed that displayed the probability of severe coronary artery disease as a function of a five-point cardiac risk scale, which incorporated these variables. Two hundred sixty-two patients (39% of the study group) were classified as high risk; 127 of these patients (48%) had three-vessel or left-main disease. An additional 96 patients were classified as low risk; nine of these patients (9%) had three-vessel or left-main disease. Five clinical variables that were obtained on an initial patient assessment can provide useful estimates of the likelihood of severe coronary disease.