In this longitudinal study, patients were recruited from the adult Emergency Service of Cook County Hospital. Key end-points included: case fatality rates from acute events; long-term survival rates; sudden versus non-sudden death rates; occurrence of first myocardial infarction among patients with new onset angina; functional recovery after myocardial infarction and coronary artery bypass graft. Baseline data were collected in all groups and include: age, sex, education, weight, height, medical history, hyperlipidemia, alcohol and cigarette use, and medications. Both two-dimensional and M-mode echocardiograms were obtained and an exercise test performed. At the time of cardiac catheterization fasting blood samples were drawn for lipid analysis. Bi-plane ventriculography and cineangiography were performed. After discharge, patients returned to the clinic at three-month intervals for up to two years. Analyses were conducted on left ventricular hypertrophy and socioeconomic status as predictors of mortality. The two control groups permitted comparisons of baseline findings and end-points. One hundred and fifty patients from each of the control groups were followed long-term, primarily through surveillance of government vital status records. The study provided data on survival rates, incidence of new events, and mode of death, the roles of sex differences and hypertension in coronary artery disease, and the efficacy of coronary artery bypass surgery.