Abstract 3061: Possibilities of Optical Coherence Tomography in identifying vulnerable plaques: a comparison with intravascular ultrasound and coronary angioscopy
[Background] Optical coherence tomography (OCT) is a new intravascular imaging method with a high resolution of approximately 10–20micrometer, which is 10-fold greater than that of intravascular ultrasound (IVUS). This may allow us to observe the pathophysiology of the atherosclerosis in the vessel wall in detail in vivo, and to estimate the vulnerable plaques. If we can identify the vulnerable plaques in vivo, it might be possible to predict the development of acute coronary syndrome (ACS). The aim of this study was to evaluate the ability of OCT in the assessment of lesion morphology in a culprit lesion of acute myocardial infarction (AMI) in comparison with IVUS and coronary angioscopy (CAS).
[Methods and Results] We enrolled 24 patients with AMI in this study, and analyzed the OCT, CAS and IVUS findings for corresponding images. The average duration from the onset of symptom to OCT imaging was 3.8 +/− 1.2 hours. In all cases, the corresponding OCT, CAS and IVUS images were obtained without complication or adverse events. The incidence of plaque rupture observed by OCT was 71%, and it was significantly higher than that by CAS (42%, p=0.042) and IVUS (33%, p=0.009). Furthermore, OCT (25%) was superior to CAS (4%, p=0.041) and IVUS (0%, p<0.001) in the detection of fibrous cap erosion. The intra-coronary thrombus was observed in all cases by OCT and CAS, but it was identified in 42% by IVUS (vs. OCT, p<0.001). Only OCT could evaluate the fibrous cap thickness, and it was 49 +/− 27μm. The incidence of thin cap fibroatheroma (TCFA) was 79% in this population. OCT and IVUS could estimate the size of lipid core, and the detection frequency of lipid rich plaques (Lipid Arch > 180 degrees) was similar in both techniques (57% vs. 62%).
[Conclusions] Intracoronary OCT is feasible and safe imaging modality in patients with AMI and allows us to identify plaque ruptures, fibrous cap erosions, TCFA and intracoronary thrombus in vivo more frequently and precisely compared with conventional imaging techniques.