The study was renewed in 1993 for one year in order to fully analyze the prospectively accumulated data on the 973 enrolled patients in the Multicenter Study of Silent Myocardial Ischemia (MSSMI). The primary goal was to determine the usefulness, or the lack thereof, of ambulatory electrocardiographic (AECG) monitoring for identifying coronary patients with jeopardized ischemic myocardium at risk for ischemic cardiac events. The aims of the study were: 1) to evaluate the reproducibility of then current methods for detecting ischemic-type changes (ST depression) on AECG; 2) to improve the accuracy and reliability of contemporary scanner-interactive methodology that had been utilized for identifying ischemic-type ST-segment changes on the AECG; 3) to complete the development on a new, innovative, and reproducible computer-based technique for automatic (operator-independent), quantitative identification of beat-to-beat ischemic-type ST depression on the MSSMI AECG tapes; 4) to evaluate the clinical utility of the improved and new ST-segment analytic techniques to identify coronary patients at risk for natural cardiac events (unstable angina, non-fatal myocardial infarction, and cardiac death) during two year follow-up in the overall MSSMI population, in selected subgroups (gender, age), and in prespecified high-risk ischemic subsets; and 5) to determine the optimal cost- effective strategy for sequencing the assessment of silent, jeopardized ischemic myocardium by clinical variables and non-invasive tests to identify coronary patients at risk for subsequent ischemic cardiac events. This research utilized statistical techniques for evaluating reproducibility of detecting ST depression on AECG (kappa statistics, analyses of variance, Cochran's Q-test), for determining ischemic risk factors for time-to-cardiac events (Cox regression analyses), and for cost-effectiveness analyses (receiver-operator characteristic curves).