The association between on-site cardiac catheterization facilities and the use of coronary angiography after acute myocardial infarction. Myocardial Infarction Triage and Intervention Project Investigators

Abstract

Background: During the past decade the use of coronary angiography after acute myocardial infarction has substantially increased. Among the possible contributing factors, the increasing availability of cardiac catheterization facilities was the focus of our investigation.

Methods: We investigated whether the availability of cardiac catheterization facilities at an admitting hospital was associated with the likelihood that a patient would undergo coronary angiography. After adjusting for age, sex, cardiac history, and cardiac complications during hospitalization, we evaluated this association in 5867 consecutive patients with acute myocardial infarction admitted to 19 Seattle-area hospitals. We also assessed the association between the presence of on-site cardiac catheterization facilities and in-hospital mortality.

Results: Patients admitted to hospitals with on-site cardiac catheterization facilities were far more likely to undergo coronary angiography (odds ratio, 3.21; 95 percent confidence interval, 2.81 to 3.67) than patients admitted to hospitals where transfer to another institution would be required to perform cardiac catheterization. Admission to a hospital with on-site facilities was more strongly associated with the use of coronary angiography than any characteristic of the patient. Although our study had limited power to detect differences in mortality, the availability of coronary angiography had no discernible association with in-hospital mortality rates (odds ratio for mortality among patients admitted to hospitals with on-site facilities vs. patients admitted to hospitals without such facilities, 0.88; 95 percent confidence interval, 0.71 to 1.09).

Conclusions: In this community-wide study, the availability of on-site cardiac catheterization facilities was associated with a higher likelihood that a patient would undergo coronary angiography. However, admission to hospitals with these facilities did not appear to be associated with lower short-term mortality.