Aspirin in the treatment of acute myocardial infarction in elderly Medicare beneficiaries. Patterns of use and outcomes.

BACKGROUND: Although aspirin is an effective, inexpensive, and safe treatment of acute myocardial infarction, the frequency of use of aspirin in actual medical practice is not known. Elderly patients, a group with low rates of utilization of effective therapies such as thrombolytic therapy, also may be at risk of not receiving aspirin for acute myocardial infarction. To address this issue, we sought to determine the current pattern of aspirin use and to assess its effectiveness in a large, population-based sample of elderly patients hospitalized with acute myocardial infarction.

METHODS AND RESULTS: As part of the Cooperative Cardiovascular Project Pilot, a Health Care Financing Administration initiative to improve quality of care for Medicare beneficiaries, we abstracted hospital medical records of Medicare beneficiaries who were hospitalized in Alabama, Connecticut, Iowa, or Wisconsin from June 1992 through February 1993. Among the 10,018 patients > or = 65 years old who had no absolute contraindications to aspirin, 6140 patients (61%) received aspirin within the first 2 days of hospitalization. Patients who were older, had more comorbidity, presented without chest pain, and had high-risk characteristics such as heart failure and shock were less likely to receive aspirin. The use of aspirin was significantly associated with a lower mortality (OR, 0.78; 95% CI, 0.70 to 0.89) after adjustment for potential confounders.

CONCLUSIONS: About one third of elderly patients with acute myocardial infarction who had no contraindications to aspirin therapy did not receive it within the first 2 days of hospitalization. The elderly patients with the highest risk of death were the least likely to receive aspirin. After adjustment for differences between the treatment groups, the use of aspirin was associated with 22% lower odds of 30-day mortality. The increased use of aspirin for patients with acute myocardial infarction is an excellent opportunity to improve the delivery of care to elderly patients.