Criteria-based expert system for cardiac ischemia evaluation in the emergency department

Objective: To develop and evaluate a cardiac ischemia computer expert system using a criteria-based expert shell for assessment of chest pain patients in a community hospital ED setting, Methods: A retrospective, comparison study of the expert system against the clinical judgment of board-certified emergency physicians (EPs) was performed in 1 community hospital ED. All chest pain patients had either a cardiac catheterization, Persantine stress testing, or both within 1 month of ED presentation. A final diagnosis of acute myocardial infarction or unstable angina by a consultant cardiologist represented the criterion standard for cardiac ischemia. Results: Of the 59 patients meeting study criteria, 28 (47%) had cardiac ischemia. The expert system had equal sensitivity (100%) and was more than twice as specific (39% vs 16%) in diagnosing ischemic cardiac disease as were the board-certified EPs (p < 0.001; McNemar's chi-square with Yates' correction). Conclusions: The criteria-based system built around a system of findings ordered by Bayes' rule has potential augment the ability of the EP to accurately diagnose ischemic heart disease.