Operator Volume and Clinical Outcomes of Primary Coronary Angioplasty for Patients With Acute Myocardial Infarction

n inverse relationship between the annual number of patients treated by a hospital or physician and rates of mortality and complications has been repeatedly documented. These volume-outcome relationships have been explored in particular detail in cardiovascular medicine, including for procedures such as coronary artery bypass graft surgery and coronary angioplasty and conditions such as acute myocardial infarction. There is considerable controversy regarding how these data should be interpreted and, in particular, whether policies should be based on hospital or physician volume. In the present issue of Circulation, Vakili and associates 1 present data on the effect of operator volume on the outcome of primary angioplasty for acute myocardial infarction. To place this study in context, we will first review the data on volume-outcome relationships, then assess why these relationships exist, and finally discuss what policies might be based on these findings.