Acute myocardial infarction in the elderly: Differences by age

OBJECTIVES We evaluated the clinical characteristics and outcomes of elderl y patients hospitalized with acute myocardial infarction (AMI) to describe differences by age. BACKGROUND Elderly patients with AMI are perceived as a homogeneous populat ion, though the extent by which clinical characteristics vary among elderly patients has not been well described. METHODS Data from 163,140 hospital admissions of Medicare beneficiaries age greater than or equal to 65 years between 1994 and 1996 with AMI at U.S. h ospitals were evaluated for differences in clinical characteristics and mor tality across five age-based strata (in years): 65 to 69, 70 to 74, 75 to 7 9, 80 to 84 and greater than or equal to 85. RESULTS Older age was associated with a greater proportion of patients with functional limitations, heart failure, prior coronary disease and renal in sufficiency and a lower proportion of male and diabetic patients. Of note, the proportion of patients presenting with chest pain within 6 h of symptom onset, and with ST-segment elevation, was lower in each successive age gro up. Thirty-day mortality rates were higher in older age groups (65 to 69: 1 0.9%, 70 to 74: 14.1%, 75 to 79: 18.5%, 80 to 84: 23.2%, greater than or eq ual to 85: 31.2%, p = 0.001 for trend). The effect of age persisted but was attenuated after adjustment for differences in patient characteristics; si milar trends were observed for one-year mortality. CONCLUSIONS Our data indicate significant age-associated differences in cli nical characteristics in elderly patients with AMI, which account for some of the age-associated differences in mortality. The practice of grouping ol der patients together as a single age group may obscure important age-assoc iated differences. (C) 2001 by the American College of Cardiology.