Abstract 6181: ST Segment Resolution and Pathological Findings of Aspirated Materials in Patients with ST Elevation Acute Myocardial Infarction

Early resolution of ST-segment elevation (STR) is a potent predictor of better clinical outcome after PCI in ST elevation acute myocardial infarction (STEMI). The aim of this study was to determine the association of aspirated materials and serial change of ST elevation. We studied 150 consecutive STEMI patients with assessable ECG recording, in whom standard PCI was performed with the adjunctive use of aspiration thrombectomy. STR(+) was defined as more than 50% resolution of ST-segment elevation at 60min after PCI. Aspirated materials were pathologically classified into thrombus only group (fresh, lytic, or organized) or thrombus and atheroma complex group, and compared between STR(+) and STR(−). TIMI flow grade, IVUS findings after aspiration(ruptured plaque, calcification, thrombus and echo signal attenuation), area under the curve (AUC) of CK-MB release, and pathological findings were also compared between the two groups. Seventy-six patients (50.6%) showed STR and 74 patients didn’t. RCA culprit lesion was significantly more frequent in STR(+)(P<0.05). There was no significant difference in other patient characteristics or IVUS findings in the present cohort. AUC of CK-MB was lower in STR(+)(p=0.02). TIMI 3 flow was more frequently achieved in STR(+)(p<0.05). Fresh thrombus was more frequent in STR(+)(p<0.05), whereas atheromatous component and lytic or organized thrombus were frequently observed in STR(−)(p<0.05). Culprit lesions in STEMI, when atheroma and thrombus complex with lytic or organized thrombus was aspirated, caused more myocardial damage and less frequent STR.