Changing Congestive Heart Failure Incidence in an Older Population, 1970-74 and 1990-94.
Congestive heart failure (CHF) mortality rates have increased dramatically in recent years, particulary among the elderly, but little is known about CHF incidence changes. This study compares CHF incidence between 1970-74 and 1990-94 in a large well-defined population of over 30,000 persons >65 y/o with access to complete medical records. Using Framingham Heart Study (FHS) criteria for confirming CHF we identified 387 and 1555 confirmed cases in the respective periods. We observed unchanging incidence rates of 7.6 and 7.9, and increasing incidence from 15.1 to 18.7 and 27.8 to 42.4 cases per 1000 person-years among persons 65-74, 75-84, and 85+ years old, respectively. In both time periods, 21% of potential cases were unconfirmed by FHS criteria. Onset of confirmed CHF occured as an outpatient in 16% and 22% of cases in the respective periods. Profiles of FHS major and minor diagnostic criteria were very similar for cases in the two timed periods. This study documents significant increase in CHF incidence among old-old(>75y/o) but not young old (65-74). Possible explanations are under study.