Beginning in the mid to late 1960's, mortality attributed to coronary heart disease (CHD) in the United States turned markedly downwards declining by approximately 2-3% annually. The reasons for this encouraging mortality decrease remain unknown, however, and CHD remains the leading cause of death in the United States. A paucity of population-based data exist to ascertain whether or not the observed secular trends in CHD remains the leading cause of death in the United States. A paucity of population-based data exist to ascertain whether or not the observed secular trends in CHD mortality rates are due to changes in the incidence rates of new coronary events, changes in survival after an acute coronary episode or combinations thereof. The present population-based study proposes to continue the examination of temporal trends in the incidence and survival rates of acute myocardial infarction (MI) and out-of hospital deaths due to CHD in the setting of the Worcester, MA, Standard Metropolitan Statistical Area (SMSA). The objectives of this study are to examine recent (1991, 1993 and 1995) as compared to prior (1975, 1978, 1981, 1984, 1986, 1988 and 1990) time trends in the annual attack rates of acute MI and out-of-hospital deaths attributed to CHD, recent (1991-1995) as well as prior (1975-1990) changes over time in the in-hospital and long-term survival rates of acute MI, and the relationship of these incidence and survival patterns of acute MI and out-of-hospital deaths due to CHD to selected socio-demographic, clinical and medical care factors. An additional objective of this study is to examine changes over time in the therapeutic management and diagnostic workup of patients hospitalized with acute MI as well as related issues of cost. To accomplish these objectives, the proposed study would be carried out within the confines of the 14 acute general hospitals in the Worcester, MA, SMSA (1990 census count=403000). This study will utilize and extend previous approaches used in the conduct of this study. In Phase I, all new (incident) and recurrent episodes of definite acute MI occurring among residents of the Worcester SMSA during calendar years 1991, 1993 and 1995 would be identified from discharge diagnostic printouts obtained from the participating Worcester SMSA hospitals. The medical records of patients from the Worcester SMSA will then be individually reviewed for validation purposes according to pre-established diagnostic criteria for acute MI> Abstraction of the medical record of patients satisfying the diagnostic and geographic eligibility criteria is then carried out with the recording of relevant data onto a standardized data collection instrument. A review of records of additional hospitalizations and a statewide and local research of death certificates will be carried out to examine the long-term survival status of discharged hospital patients from each of the presently proposed study years (1991, 1993 and 1995) as well as those of previous study years (1975-1990). In the second phase of this study, death certificates of Worcester SMSA residents will be reviewed to identify cases of out-of-hospital deaths due to CHD occurring in 1991, 1993 and 1995 in order to determine temporal trends in these incidence rates. The results of this community-wide investigative will provide important insights from a 20 year vantage point concerning the role of primary and secondary preventive and therapeutic efforts to declining CHD mortality rates as it affects the population of a large representative metropolitan area.