Relation Between Hospital Primary Angioplasty Volume and Mortality for Patients With Acute MI Treated With Primary Angioplasty vs Thrombolytic Therapy

CONTEXT Institutional experience with primary angioplasty has been suggested as a factor in selecting a reperfusion strategy for patients with acute myocardial infarction (AMI). However, no large studies have directly compared outcomes of primary angioplasty vs thrombolytic therapy as a function of institutional experience. OBJECTIVE To compare outcomes among patients with AMI who were treated with primary angioplasty vs thrombolytic therapy at hospitals with different volumes of primary angioplasty. DESIGN Retrospective cohort. SETTING A total of 446 acute care hospitals with 112 classified as low volume (≤16 procedures), 223 as intermediate volume (17-48 procedures), and 111 as high volume (≥49 procedures) based on their annual primary angioplasty volume. PATIENTS A total of 62 299 patients with AMI treated with primary angioplasty or thrombolytic therapy from June 1, 1994, through July 31, 1999. MAIN OUTCOME MEASURE In-hospital mortality. RESULTS Mortality was lower among patients who received primary angioplasty compared with those who received thrombolysis at hospitals with intermediate volumes (4.5% vs 5.9%; P