Abstract 19890: Differences in Plaque Characteristics Between Symptomatic and Asymptomatic Plaque Ruptures Assessed by Optical Coherence Tomography and Intravascular Ultrasound
Backgrounds: Plaque rupture and thrombus formation play key roles in the onset of acute coronary syndrome (ACS). However, previous studies have reported the presence of asymptomatic plaque ruptures not causing ACS. We sought to investigate the morphological differences between symptomatic and asymptomatic plaque ruptures using optical coherence tomography (OCT) and intravascular ultrasound (IVUS).
Methods and Results: We examined 273 coronary arteries from 246 patients (119 : ACS, 127 : stable angina pectoris (SAP)) who underwent OCT and IVUS examinations before percutaneous coronary intervension (PCI). Plaque rupture was documented by OCT examination. Symptomatic plaque rupture (SPR) was defined as plaque rupture in the culprit lesion of ACS. Asymptomatic plaque rupture (non-SPR) was defined as plaque rupture in the non-culprit lesion of ACS or in the lesion of SAP. Qualitative and quantitative OCT and IVUS assessments were performed and the results were compared between SPR and non-SPR. In total, fifty-one SPRs and 27 non-SPRs were observed (0.33/patient). Fibrous cap thickness was significantly thinner in SPR group (55±12μm vs 69±26μm, p <0.01) and lipid content was significantly greater in SPR group than in non-SPR group (lipid arc ≥ 3 quadrants : 92.2% vs 55.6%, p<0.01). OCT identified predominantly red thrombus in lesions of both groups, whereas the frequency of the presence of thrombus was significantly greater in SPR group than in non-SPR group (red thrombus : 62.8% vs 11.1%, p <0.01; white thrombus : 33.3% vs 3.7%, p <0.01). In IVUS analysis, there was no significant difference in % plaque area and remodeling index between the two groups (0.88±0.05 vs 0.88±0.07,p=0.82, 1.17±1.21 vs 1.21±0.20, p=0.30). Minimum lumen area was significantly smaller in SPR group (2.30±0.61 vs 2.63±0.72, p=0.04). In clinical characteristics, white blood cell counts were significantly greater in SPR group and multiple plaque ruptures were more frequently observed in SPR group than in non-SPR group..
Conclusions: OCT analysis revealed larger lipid content and thinner cap thickness in SPR than in non-SPR. Local lesion morphology might be correlated with clinical presentations although systemic or patient-related factors seems to be important determinant factors.
- © 2010 by American Heart Association, Inc.