The effect of pre-infarction unstable angina on the size of myocardial necrosis

Introduction and objectives. Recent studies suggest that preinfarction angi na (PA) might induce less myocardial necrosis. The objective of this study is to evaluate whether patients with PA have smaller myocardial infarctions . Methods, Patients with acute myocardial infarction of less than 12 hours si nce the onset symptoms were included. PA was defined as unstable angina at rest during the 7 days before the infarction. Infarct size was assessed wit h the area under the curve of OK-MB levels in the 24 hours following the on set of the infarct. Results. One hundred-seventy nine patients were included, 75 (41.9%) with P A. There were more men in the group with PA (89.3% vs 70.2%, p = 0.004) and a higher prevalence of ex-smokers (38.7% vs 19.2%, p = 0,006). We did not find significant differences in myocardial infarction size between both gro ups, but a statistically significant interaction between PA and pre-treatme nt with sulfonylurea drugs was noted (p = 0.050). Conclusions. Preinfarction angina does not seem to induce less myocardial n ecrosis in this study. There is a significant interaction between preinfarc tion angina and pre-treatment with sulfonylurea drugs.