Diabetes mellitus and outcome after primary coronary angioplasty for acutemyocardial infarction: Lessons from the GUSTO-IIb angioplasty substudy

OBJECTIVES We sought to compare the efficacy of primary angioplasty in diab etics versus nondiabetics and to evaluate the relative benefits of angiopla sty over thrombolytic therapy among diabetics. BACKGROUND Primary angioplasty for myocardial infarction is at least as eff ective as thrombolytic therapy in the general population. However, the infl uence of diabetic status on outcome after primary angioplasty versus thromb olysis remains unknown. METHODS Patients in the Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) Angioplasty Substudy were randomize d to receive either primary angioplasty or accelerated alteplase. The inter action of diabetic status (diabetics n = 177, nondiabetics n 961) and treat ment strategy with the occurrence of the primary end point (death, nonfatal reinfarction or nonfatal, disabling stroke at 30 day;) was analyzed (power to detect a 40% relative reduction in the primary end point with alpha = 0 .05 and beta = 0.20). Among patients who were randomized to and underwent p rimary angioplasty, procedural success (defined as residual stenosis <50% a nd TIMI grade 3 how) was assessed based on diabetic status. RESULTS Compared with nondiabetics, diabetics had worse baseline clinical a nd angiographic profiles. Despite more severe stenosis and poorer flow in t he culprit artery, procedural success with angioplasty was similar for diab etics (n = 81; 70.4%) and nondiabetics (n = 391; 72.4%). Outcome at 30 days was better for nondiabetics randomized to angioplasty versus alteplase (ad justed odds ratio, 0.62; 95% confidence interval, 0.41-0.96) with a similar trend for diabetics (0.70, [0.29 -1.72]). We noted no interaction between diabetic status and treatment strategy on outcome (p = 0.88). CONCLUSIONS Primary angioplasty was similarly successful in diabetics and n ondiabetics and appeared to be more effective than thrombolytic therapy amo ng diabetics with acute infarction. (C) 2000 by the American College of Car diology.