In the community surveillance component, the four communities are investigated to determine the long term trends in hospitalized MI and CHD deaths. The target population of men and women aged 35-84 years was approximately 446,000 at the end of surveillance in 2014. Events are abstracted and then investigated by review of hospital records. Physicians and family members are also queried in some instances. Each event is assigned a standardized classification. Surveillance of inpatient heart failure in men and women ages 55 years and older began in 2005 and continued until 2014.