Diagnosis of acute myocardial infarction in the emergency room: a prospective assessment of clinical decision making and the usefulness of immediate cardiac enzyme determination

Abstract

This study evaluates (a) the ability of house staff physicians to diagnose acute myocardial infarction (AMI) in patients with chest pain and (b) the usefulness of immediate ("stat") creatine kinase determinations in aiding the decision to hospitalize patients with chest pain. Of 80 emergency room patients with chest pain, 34 were admitted to an intensive care unit and 46 were either discharged or admitted to a general medical unit. Of the 34 patients admitted to intensive care, 11 fulfilled criteria for AMI. Of the 46 who were not admitted, two met criteria for AMI: one had abnormal initial enzyme values; the other had normal initial values but diagnostic 48-hour values. Both had abnormal electrocardiograms. On the other hand, 11 patients who were not admitted had elevated initial enzyme values but did not have myocardial infarctions and might have been admitted inappropriately on the basis of their initial enzyme values. Five patients who were admitted had normal initial values but did develop infarctions and might have been sent home inappropriately on the basis of initial enzymes values. We conclude that: (a) physicians discharged 2 of 13 patients with AMI drawn from a population of 80 with chest pain and (b) the availability of stat cardiac enzymes could have prevented the discharge of only 1 patient and may have caused the inappropriate admission of 11 and discharge of 5 patients.