Abstract 3325: Evaluation Of Coronary Lesion Morphology In Patients With Various Clinical Presentations By Optical Coherence Tomography
[Background] The pathophysiology of coronary plaque erosion is not fully elucidated yet, because the conventional imaging techniques are limited in the assessment of plaque microstructure in vivo. Intracoronary optical coherence tomography (OCT) is new imaging modality with high resolution of 10 micrometer, and it has potentials to identify not only plaque rupture but also plaque erosion. The purpose of this study was to evaluate the frequency of coronary plaque erosion in patients with various clinical presentations.
[Methods and Results] One hundred four patients, who had OCT examination in the culprit lesion, were enrolled and categorized according to their clinical presentation: acute myocardial infarction (AMI; n=30), unstable angina pectoris (UAP; n=11) or stable angina pectoris (SAP; n=63). There was a significant difference among the groups with respect to the frequency of plaque rupture (73%, 27% and 3%, in AMI, UAP and SAP, respectively; p<0.0001) In parewise comparison, the frequency of plaque rupture was significantly different between AMI and SAP (p=0.0119), between AMI and SAP (p<0.0001) and between UAP and SAP (p=0.0213). The difference in the frequency of plaque erosion was also significant among the groups (23%, 36% and 2%, in AMI, UAP and SAP, respectively; p=0.0002). In addition, the frequency of plaque erosion was significantly different between AMI and SAP (p=0.0013) and between UAP and SAP (p=0.0013) but not between AMI and UAP (p=0.4453). The thrombus was noted in 100% of the patients with AMI, 64% of those with ACS, and 5% of those with SAP (p<0.0001). The fibrous cap thickness was significantly different among the groups (49 +/− 21, 113 +/− 64 and 305 +/− 97 micrometer, in AMI, UAP and SAP, respectively; p<0.0001). Thin cap fibroatheroma (fibrous cap thickness < 65 micrometer) was detected in 83% of the patients with AMI, 36% of those with ACS, and 3% of those with SAP (p<0.0001).
[Conclusion] Not only plaque rupture but also plaque erosion was observed more frequently in patients with AMI and UAP than SAP. Although the frequency of plaque rupture was higher in AMI than that in UAP, the frequency of plaque erosion was similar between them.