Usefulness of ST-segment changes in ≥2 leads on the emergency room electrocardiogram in either unstable angina pectoris or non-Q-wave myocardial infarction in predicting outcome

To determine the reliability of the admission electrocardiogram in predicting outcome in patients hospitalized for chest pain at rest, 90 patients were randomized into a trial of aspirin versus heparin in unstable angina or non-Q-wave myocardial infarction, and prospectively followed for 3 months. The emergency room admission electrocardiogram was analyzed for ST-segment deviation ≥1 mm/lead and T-wave changes. Unfavorable outcomes were recurrent ischemic pain, myocardial infarction and coronary revascularization with angioplasty or surgery. In patients who underwent coronary arteriography, a myocardium in jeopardy score ranging from 0 to 10 was assigned, based on the number of vessels with a diameter stenosis ≥70% and the location of the stenoses. Considering all 90 patients, an admission electrocardiogram with ST-segment deviation in ≥2 leads had a positive predictive value for adverse clinical events of 79% and a negative predictive value of 64%. In the subset of patients without left ventricular hypertrophy and whose admission electrocardiograms were recorded during chest pain (62 of 90), the positive predictive value of ST deviation in ≥2 leads improved to 89% and the negative value to 72%. Of the 62 patients, 53 underwent coronary arteriography. There was a positive linear correlation between the total number of leads with ST-segment deviation and the myocardium in jeopardy score (r = 0.80, p < 0.001). In patients with unstable angina or non-Q-wave myocardial infarction, an admission electrocardiogram recorded during pain and revealing ST-segment changes in ≥2 leads is by itself a reliable predictor of major clinical events. The total number of leads with ST changes predicts the extent of myocardium in jeopardy.