Angiographic findings and catheterization laboratory events in patients with primary coronary angioplasty or streptokinase therapy for acute myocardial infarction

BACKGROUND: The purpose of this study was to evaluate catheterization laboratory events and angiographic findings in patients randomly assigned to undergo primary coronary angioplasty or to receive intravenous streptokinase for acute myocardial infarction. METHODS: We analysed angiographic data in 301 patients with acute myocardial infarction, randomly assigned to undergo primary coronary angioplasty without antecedent thrombolytic therapy or to receive intravenous streptokinase therapy. Follow-up coronary angiography was preferably performed after 3 months. All angiograms were analysed with a quantitative coronary analysis system. RESULTS: Of the 152 patients assigned to angioplasty treatment, 140 underwent this procedure with a success rate of 97%. The residual diameter stenosis of the infarct-related vessel immediately after angioplasty was 27 +/- 15% and there were major events in 14% of the patients in the catheterization laboratory. At follow-up angiography after a mean interval of 92 days in the angioplasty assigned patients, a diameter stenosis of 35 +/- 22% was observed in this group. The restenosis rate was 28% and the reocclusion rate 5%. A Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow immediately after angioplasty was predictive for reocclusion at follow-up (P = 0.001). In the streptokinase assigned patients (149) the infarct-related vessel was patent at follow-up angiography after a mean of 22 days in 66% of the patients with a mean residual diameter stenosis of 77 +/- 20%. CONCLUSION: Primary coronary angioplasty is a highly effective and safe reperfusion modality for patients with acute myocardial infarction. However, TIMI grade 2 flow through the infarct-related vessel immediately after angioplasty is a predictor of reocclusion.