Assessment of Culprit Lesion Morphology in Acute Myocardial Infarction Ability of Optical Coherence Tomography Compared With Intravascular Ultrasound and Coronary Angioscopy

ObjectivesThe aim of the present study was to evaluate the ability of optical coherence tomography (OCT) for assessment of the culprit lesion morphology in acute myocardial infarction (AMI) in comparison with intravascular ultrasound (IVUS) and coronary angioscopy (CAS).BackgroundOptical coherence tomography is a new intravascular imaging method with a high resolution of approximately 10 μm. This may allow us to assess the vulnerable plaques in detail in vivo.MethodsWe enrolled 30 patients with AMI, and analyzed the culprit lesion by OCT, CAS, and IVUS.ResultsThe average duration from the onset of symptom to OCT imaging was 3.8 ± 1.0 h. The incidence of plaque rupture observed by OCT was 73%, and it was significantly higher than that by CAS (47%, p = 0.035) and IVUS (40%, p = 0.009). Furthermore, OCT (23%) was superior to CAS (3%, p = 0.022) and IVUS (0%, p = 0.005) in the detection of fibrous cap erosion. The intracoronary thrombus was observed in all cases by OCT and CAS, but it was identified in 33% by IVUS (vs. OCT, p < 0.001). Only OCT could estimate the fibrous cap thickness, and it was 49 ± 21 μm. The incidence of thin cap fibroatheroma (TCFA) was 83% in this population by OCT.ConclusionsOptical coherence tomography is a feasible imaging modality in patients with AMI and allows us to identify not only plaque rupture, but also fibrous cap erosion, intracoronary thrombus, and TCFA in vivo more frequently compared with conventional imaging techniques

Implication of Plaque Color Classification for Assessing Plaque Vulnerability A Coronary Angioscopy and Optical Coherence Tomography Investigation

ObjectivesThe purpose of this study was to assess the relationship between plaque color evaluated by coronary angioscopy and fibrous cap thickness estimated by optical coherence tomography (OCT) in vivo.BackgroundYellow color intensity of coronary plaque evaluated by coronary angioscopy might be associated with plaque vulnerability.MethodsSeventy-seven coronary artery plaques in patients with acute coronary syndrome were observed by angioscopy and OCT. Plaque color was graded as white, light yellow, yellow, or intensive yellow.ResultsThere were significant differences among the groups classified by plaque color with respect to the fibrous cap thickness estimated by OCT: 389 ± 74 μm in white plaques, 228 ± 51 μm in light yellow plaques, 115 ± 28 μm in yellow plaques, and 59 ± 14 μm in intensive yellow plaques (p &lt; 0.0001). In Spearman rank-order correlation analysis, there was a significant negative correlation between yellow color intensity and fibrous cap thickness (p &lt; 0.0001). Furthermore, 80% of intensive yellow plaques were thin cap fibroatheroma with a cap thickness of ≤65 μm.ConclusionsThe plaque color in coronary angioscopy was determined by the fibrous cap thickness, which was assessed by OCT. Although coronary angioscopy remains a specialized research tool, it might allow us to evaluate plaque vulnerability