From the Department of Health Care Policy, Harvard Medical School, Boston (E.G., M.B.L., B.J.M.); the Health, Education, and Human Services Division, General Accounting Office, Washington, D.C. (E.A.P., M.T.G.); the Section of Cardiology, Department of Medicine, Boston University School of Medicine, Boston (T.J.R.); and the Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston (B.J.M.).

Address reprint requests to Dr. Guadagnoli at the Department of Health Care Policy, Harvard Medical School, 180 Longwood Ave., Boston, MA 02115-5899, or at:  guadagnoli@hcp.med.harvard.edu

Background:  Previous studies have documented that cardiac procedures are performed less frequently in patients enrolled in managed-care plans than in those with fee-for-service coverage. However, it is not known whether this difference is due to less frequent use of cardiac procedures when they are indicated or to less frequent use when they are not indicated.

Methods:  We compared the use of coronary angiography after acute myocardial infarction among Medicare beneficiaries who had traditional fee-for-service coverage with the use among Medicare beneficiaries enrolled in managed-care plans. The analysis was adjusted for differences in demographic and clinical characteristics of the patients and for characteristics of the hospitals to which they were admitted. We studied more than 50,000 beneficiaries in seven states and evaluated their care according to guidelines proposed by the American College of Cardiology and the American Heart Association (ACC-AHA).

Results:  Among the 44 percent of patients in both groups who had ACC-AHA class I indications (those for which angiography is useful and effective), more fee-for-service beneficiaries than managed-care enrollees underwent angiography (46 percent vs. 37 percent, P<0.001). The rate of angiography was very low among patients with class I indications who were admitted to hospitals without angiography facilities (31 percent in the fee-for-service group and 15 percent in the managed-care group, P<0.001). Among patients with class III indications (those for which angiography is not effective), the rate of use was low in both groups (approximately 13 percent).

In conclusion, in situations in which angiography is considered to be useful, it was used less often in  managed-care enrollees than in fee-for-service beneficiaries. This was true whether the patients were admitted to hospitals with angiography facilities or without them and even when we compared angiography rates among Medicare beneficiaries enrolled in specific plans with the rates among fee-for-service beneficiaries in the same hospital service areas.  Nevertheless, the level of underuse was high in both cohorts, suggesting that there is room for improving the care of elderly patients with myocardial infarction, regardless of the type of Medicare coverage, and especially those initially admitted to hospitals without angiography facilities. 

The views expressed in this article are those of the authors and not necessarily those of the General Accounting Office.

We are indebted to Christina Fu and Margaret Volya for assistance with statistical programming; to Laurie Silva for assistance with project management; and to Dr. Mary Cummings of the Agency for Healthcare Research and Quality , who served as the project officer for this study.

The following criteria were used for assigning patients to an ACC-AHA class:

Criteria for class I -- The presence of one or both of the following: an episode of myocardial ischemia (manifested as chest pain after arrival at the hospital, ischemia on a stress test, or both) and persistent hemodynamic instability (manifested as cardiogenic shock on arrival at the hospital or during the hospital stay, hypotension during the hospital stay, congestive heart failure or pulmonary edema with an ejection fraction of 40 percent or less, or a combination of these findings).

Criteria for class IIa -- The absence of class I indications and the presence of one or more of the following: an ejection fraction of 40 percent or less, prior revascularization, and congestive heart failure or pulmonary edema.

Criterion for class IIb -- The presence of myocardial infarction without complications.

Criteria for class III -- The presence of one or more of the following: hepatic failure, metastatic cancer, terminal illness, a do-not-resuscitate order in force at the time of admission, and decorticate or decerebrate posturing or a lack of motor response.