INFLUENCE OF REGIONAL CARDIOVASCULAR MORTALITY ON THE USE OF ANGIOGRAPHY AFTER ACUTE MYOCARDIAL-INFARCTION

Utilization of angiography after acute myocardial infarction (AMI) tre ated with thrombolytics has been shown in large clinical trials to be related primarily to the availability of the procedure and not individ ual clinical circumstances. This study evaluated the regional influenc e of overall population cardiovascular mortality on utilization of ang iography in the United States participants of the Global Utilization o f Streptokinase and t-PA for Occluded Arteries (GUSTO-1) trial. Publis hed summary statistics from GUSTO-1 and U.S. Census Bureau 1991 delta were evaluated using simple and multiple linear regression with analys is for outliers. Region predictor variables (age adjusted) included me an total cardiovascular deaths/100,000/year (ICD/9 codes 390 to 459), mean coronary artery disease deaths/100,000/year (ICD/9 codes 410 to 4 14), and mean stroke deaths/100,000/year (ICD/9 codes 430 to 438), wit h the major outcome being regional proportion of GUSTO-1 patients unde rgoing angiography during the hospital stay after treatment with throm bolysis. All 3 cardiovascular death rates varied significantly by regi on (p < 0.00002) with no significant difference in GUSTO-I mortality b y region (p = 0.25). Simple linear regression analysis revealed associ ations between regional death rates and angiography use (r = 0.60, p = 0.12; r = 0.39, p = 0.33; r = 0.81, and p = 0.015). Multiple stepwise linear regression analysis found regional death rate due to stroke as the strongest predictor of angiography use with 65.86% of the variati on explained by the model. New England was found to be a consistent ou tlier with reduced angiography use because of its background regional disease burden. This study confirms regional bias in the use of angiog raphy in GUSTO-1. This form of operator bios appears to be due to more aggressive practice patterns in regions, except New England, where th e overall cardiovascular disease burden is greater in terms of lives l ost per 100,000 per year. (C) 1997 by Excerpta Medica, Inc.