Performance and potential impact of a chest pain prediction rule in a large public hospital

PURPOSE: To evaluate the performance of a previously validated prediction r ule for patients presenting to the emergency department with chest pain and the potential impact of the rule on triage decisions. SUBJECTS AND METHODS: In a prospective cohort study, physician investigator s interviewed consecutive patients admitted for suspected acute ischemic he art disease (n = 207) by emergency department attending physicians who had not used the prediction rule. We measured the accuracy of the rule in predi cting cardiac complications in these patients, and compared actual triage d ecisions with those that might have been recommended by use of the predicti on rule. We also measured comorbid illnesses among patients stratified as v ery low risk by the prediction rule, as well as the effect of standardizing the definition of unstable angina and interpretation of electrocardiograms (ECG) on the rule's sensitivity and specificity. RESULTS: Overall, the rate of major cardiac complications (4.3%) was simila r to that reported in the original study (3.6%). The prediction rule perfor med well in predicting these complications in our patients (area under rece iver operating characteristic curve 0.84 versus 0.80 in the original study; difference 0.04, 95% confidence interval [CI] -0.07, 0.14). Standardized d efinitions of unstable angina and interpretation of ECGs improved the speci ficity of the prediction rule in predicting complications (55% versus 47%; difference 8%, 95% CI 1.5%, 13.7%). The prediction rule recommended admissi on to telemetry units in 65 fewer patients than actually occurred (31% of t he entire cohort). None of these patients had major complications. A substa ntial minority of "very low risk" patients (27%) had comorbid illnesses req uiring inpatient treatment. CONCLUSIONS: This independent validation of the prediction rule suggests th at it can improve triage decisions for patients admitted with suspected acu te ischemic heart disease. Additional studies are needed to test prospectiv ely the performance of the prediction rule in actual decision making, its a cceptance by clinicians, and its cost effectiveness. (C) 1999 by Excerpta M edica, Inc.