Assessment of Culprit Lesion Morphology in Acute Myocardial Infarction

OBJECTIVES: The 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). BACKGROUND: Optical coherence tomography is a new intravascular imaging method with a high resolution of approximately 10 microm. This may allow us to assess the vulnerable plaques in detail in vivo. METHODS: We enrolled 30 patients with AMI, and analyzed the culprit lesion by OCT, CAS, and IVUS. RESULTS: The 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 microm. The incidence of thin cap fibroatheroma (TCFA) was 83% in this population by OCT. CONCLUSIONS: Optical 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.