Abstract 4185: Impact of Plaque Composition at Culprit Lesions on Myocardial Microcirculation Following Primary Angioplasty in Patients With ST-segment Elevation Myocardial Infarction -Virtual Histology Intravascular Ultrasound Analysis
The influence of plaque composition in culprit lesions on myocardial microcirculation following percutaneous reperfusion remains to be elucidated. We thought to assess the relationship between plaque composition and myocardial perfusion after primary angioplasty. A total of consecutive 101 patients with ST-segment elevation myocardial infarction (STEMI) were enrolled. Patients were divided into 3 groups according to ST-segment resolution (STR) at 60 min after angioplasty: Group A (complete: STR ≥70%, n=26), Group B (partial: 30% < STR <70%, n=55) and Group C (none: STR ≤30%, n=20). We assessed the relationship between plaque composition by VH-IVUS and STR. The no-reflow phenomenon was observed in 26 patients (group A: 11.5% vs. group B: 23.6% vs. group C: 55%, p=0.001). Total plaque volume (PV) and necrotic core volume (NCV) was significantly higher in the group C than the group A and B (PV: 93.3±29.1 mm3 vs. 105.8±31.5 mm3 vs. 146.6±38.0 mm3, p<0.001, NCV: 11.9±6.3 mm3 vs. 17.3±9.7 mm3 vs. 25.4±8.0 mm3, p<0.001). There were negative liner relations between PV and STR, NCV and STR (r=−0.46, p<0.0001, r=−0.44, p<0.0001, respectively). Receiver-operating characteristic analysis revealed that PV and NCV can predict STR ≤30%, and the optimal cut-off point (sensitivity/specificity) was 123.4 mm3 (75.0%/75.3%) for PV and 20.3 mm3 (75.0%/74.1%) for NCV. Culprit plaque with high NCV and large plaque burden is closely associated with poor ST-segment resolution after revascularization. Pre-intervention VH-IVUS analysis can provide useful information regarding myocardial perfusion state following primary angioplasty.