The increased use of diagnostic procedures in patients with acute myocardial infarction. A community-wide perspective

Abstract

As part of a community-wide study examining time trends in the incidence and case-fatality rates of 3263 patients hospitalized with validated acute myocardial infarction (MI) during the years 1975, 1978, 1981, and 1984, we examined changes over time in the use of various noninvasive and invasive diagnostic tests during hospitalization for acute MI. In terms of the noninvasive procedures, exercise testing before hospital discharge increased from only 0.1% of patients in 1975 to 40.3% in 1984, while use of echocardiography (2.5%, 1975; 15.3%, 1984), Holter monitoring (1.0%, 1975; 34.0%, 1984), and radionuclide ventriculography (2.6%, 1975; 52.7%, 1984) also increased dramatically. Concerning the invasive procedures, use of coronary arteriography in patients with acute MI increased from 3.1% in 1975 to 9.8% in 1984. A more striking increase was noted in the use of pulmonary artery catheterization (7.2%, 1975; 19.9%, 1984). Examination of patient characteristics associated with the use of these tests demonstrated that the increased use of these diagnostic procedures was not due to changes in the clinical characteristics of patients hospitalized with acute MI; rather, it was the result of changes in physician practice patterns. If the practice patterns seen in this community-based study are similar to those seen throughout the United States, the charges for these diagnostic tests in 1984 are estimated to approach 600 million dollars. Given current interest in cost-containment and evaluation of clinical practices, these results suggest the need for further observational studies and clinical trials to assess the cost-effectiveness of these diagnostic tests. To assess the cost-effectiveness, it will be necessary to determine if the use of these tests improves the short-term or long-term prognosis of patients hospitalized with acute MI.