Abstract 17681: The Evaluation by Optical Coherence Tomography for the Vulnerability in Lesions with Echo Signal Attenuation on Intracoronary Ultrasound
Backgrounds: Recent several studies have reported that echo signal attenuation (EA) without dense calcification detected on intravascular ultrasound (IVUS) might be more frequently detected in acute coronary syndrome (ACS) and might be related with the worse outcome after percutaneous coronary intervention (PCI) in patients with coronary artery disease. However, the relationship between EA on IVUS and pathological vulnerable plaque components has not been fully clarified. We tried to assess the coronary plaque vulnerability of lesions with EA by using virtual histology IVUS (VH-IVUS) and optical coherence tomography (OCT) which could provide high-resolution imaging method for plaque characterization.
Methods: We investigated 41 lesions in 41 consecutive patients with coronary artery disease (23 patients with ACS and 18 patients with non-ACS) that underwent pre-intervention VH-IVUS and OCT. Atherosclerotic plaque showing ultrasound signal attenuation without very high intensity echo reflectors was defined as EA on IVUS. All lesions were divided into the two groups; lesions with EA or without. The differences of plaque morphologies among the two groups were evaluated. When the lipid arc was more than 90 degree by OCT, the plaque was defined as lipid rich plaque. A plaque with fibrous cap thickness of <70μm overlying lipid content for< 90 degrees by OCT was defined as OCT derived TCFA.
Results: EA on IVUS was detected in 12 (29.3%) lesions. Lesion vessel area (18.8±4.6mm2 vs. 14.4±5.4mm2, p=0.02), lesion plaque area (15.6±4.1mm2 vs. 11.6±5.1mm2, p=0.01), and fibrofatty plaque area by VH-IVUS (2.7±1.8mm2 vs. 1.2±0.9mm2, p=0.02) was significantly greater in lesions with EA than without. OCT revealed that the frequency of lipid rich plaque (91.7% vs. 55.2%, p=0.03), OCT-derived TCFA (91.7% vs. 41.4%, p=0.04) and superficial spotty calcification (83.3% vs. 20.7%, p<0.001) were significantly higher and minimum fibrous cap thickness was significantly thinner (69.1±36.8μm vs. 174.5±87.2μm, p<0.001) in lesions with EA than without.
Conclusion: The presence of EA on IVUS might suggest the existence of vulnerable plaque compositions.
- © 2010 by American Heart Association, Inc.