Identifying vulnerable plaque is important for preventing an acute coronary event. The present study examined the relationship between the clinical presentation of coronary artery disease and the plaque characteristics of nonculprit segment assessed by virtual histology intravascular ultrasound (VH-IVUS). Method: We performed VH-IVUS analysis on nonculprit segments with <50% diameter stenosis in 91 patients (48 acute coronary syndrome [ACS] patients, 43 stable angina [SA] patients). Results:

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... patients showed significantly higher ratio of dense calcium (7.9%±1.0% versus 5.0%±0.9%, p = 0.03) and necrotic core plaque (13.7%±1.1% versus 8.6%±1.1%, p = 0.001) compared with SA patients. VH-IVUS-derived thin-cap fibroatheroma (VH-TCFA) was more frequently observed in ACS patients compared with SA patients (64.6% versus 35.7%, p = 0.006). Among ACS patients, plasma high sensitivity C-reactive protein (hs-CRP) levels were significantly higher in patients with VH-TCFA than in patients without VH-TCFA (7.9±2.6 mg/l versus 1.6±0.3 mg/l, p = 0.004). Conclusion: ACS patients presented higher prevalence of VH-TCFA in nonculprit segment. Presence of VH-TCFA was associated with an increased level of plasma hs-CRP in ACS patients.