Mortality Surveillance: The mortality surveillance was a continuation of a surveillance study performed by the investigators since 1960 for the state of Minnesota. Mortality data for hypertension, stroke, coronary heart disease, and all cardiovascular renal disease were monitored for the Twin City metropolitan area with a total population of two million. Age, sex, area, location of death and cause-specific death rates were followed. Trends in cancer, diabetes, and other non-cardiovascular disease were examined. Case fatality rates, including one- and five-year survivorships were determined and related to coronary heart disease mortality trends.