In-stent restenosis-prone coronary plaque composition: A retrospective virtual histology-intravascular ultrasound study.

Background: The mechanism of in-stent restenosis (ISR) is multifactorial, which includes biological, mechanical and technical factors. This study hypothesized that increased inflammatory reaction, which is known to be an important atherosclerotic process, at a culprit lesion may lead to higher restenosis rates. Methods: The study population consisted of 241 patients who had undergone percutaneous coronary intervention with virtual histology-intravascular ultrasound (VH-IVUS) and a 9-month follow-up coronary angiography. Compared herein is the coronary plaque composition between patients with ISR and those without ISR. Results: Patients with ISR (n = 27) were likely to be older (66.2 +/- 9.5 years vs. 58.7 +/- 11.7 years, p = 0.002) and have higher levels of high-sensitivity C-reactive protein (hs-CRP, 1.60 +/- 3.59 mg/dL vs. 0.31 +/- 0.76 mg/dL, p < 0.001) than those without ISR (n = 214). VH-IVUS examination showed that percent necrotic core volume (14.3 +/- 8.7% vs. 19.5 +/- 9.1%, p = 0.005) was higher in those without ISR than those with ISR. Multivariate analysis revealed that hs-CRP (odds ratio [OR] 3.334, 95% confidence interval [CI] 1.158-9.596, p = 0.026) and age (OR 3.557, 95% CI 1.242-10.192, p = 0.018) were associated with ISR. Conclusions: This study suggests that ISR is not associated with baseline coronary plaque composition but is associated with old age and increased expression of the inflammatory marker of hs-CRP.