Histopathological heterogeneity of in-stent restenosis in four coronary endarterectomy specimens

Hypersensitivity and in-stent restenosis in coronary stent materials

Coronary heart disease (CHD) is a type of cardiovascular disease with the highest mortality rate worldwide. Percutaneous transluminal coronary intervention (PCI) is the most effective method for treating CHD. However, in-stent restenosis (ISR), a long-term complication after PCI, affects the prognosis of patients with CHD. Previous studies have suggested that hypersensitivity reactions induced by metallic components may be one of the reasons of this complication. With the emergence of first- and second-generation drug-eluting stents (DES), the efficacy and prognosis of patients with CHD have greatly improved, and the incidence of ISR has gradually decreased to less than 10%. Nevertheless, DES components have been reported to induce hypersensitivity reactions, either individually or synergistically, and cause local inflammation and neointima formation, leading to long-term adverse cardiovascular events. In this article, we described the relationship between ISR and hypersensitivity from different perspectives, including its possible pathogenesis, and discussed their potential influencing factors and clinical significance.

The value of peripheral blood eosinophil count in predicting in-stent restenosis in patients with stable angina pectoris undergoing drug eluting stenting

INTRODUCTION

In-stent restenosis (ISR) remains a major limitation of percutaneous coronary intervention (PCI). A role for peripheral blood cells as major regulators of immune and inflammatory systems has been proposed. We aim to evaluate the relationship between eosinophil count and development of restenosis after drug-eluting stent (DES) implantation.

METHODS

In this prospective study, all consecutive patients undergoing elective DES implantation for chronic stable angina (CSA) in a university-affiliated heart center within a 6-month period were enrolled and followed for another 6 months. Complete blood count with differentiation was performed 6 weeks after the index procedure. During the follow-up period, the cohort of patients who developed ISR was compared to the cohort of patients without ISR, descriptively and the total number of eosinophilic white cells was used to predict the occurrence of ISR.

RESULTS

153 men and 48 women with CSA underwent PCI with DES implantation, from which, 26 patients needed repeat coronary angiography for recurrent symptoms. There was an established ISR in 17 (8.5%) patients. The total number of eosinophils in their peripheral blood was 267 ± 132 cells/μL in patients with ISR, significantly higher than the number of eosinophils in those without ISR 174 ± 133 cells/μL (P-value < 0.010). Eosinophil count remained an independent predictor of ISR in multivariate analysis as the eosinophil count value over 242 cells/μL had sensitivity of 66.7% and specificity of 84.5% for the presence of ISR.

CONCLUSION

The total number of eosinophils, counted 6 weeks after DES implantation, prevails as the sole predictor of ISR occurrence in our study. This suggests an association between immune sensitivity reaction to DES material and development of ISR in patients after PCI.

TLR3 and TLR4 as potential clinical biomarkers for in-stent restenosis in drug-eluting stents patients

In-stent restenosis is still a clinic trouble for percutaneous coronary intervention in drug-stent era. The molecular basis of restenosis is intensively associated with inflammation. TLR3 and TLR4 as innate immune factors have been proven to play a key role in atherosclerosis disease. The aim of this study is to study the TLR3 and TLR4 expressions and their downstream signaling proteins in the inflammatory process of restenosis after drug-stent therapy. mRNA and protein expression of TLR3 and TLR4 were detected in peripheral blood monocytes of primary group (n = 38), N-ISR group (n = 36) and ISR group (n = 33). Some inflammatory factors (including TLR3 and TLR4) were evaluated in serum of three groups. mRNA and protein expression of TLR3 and TLR4 and their downstream signaling proteins have shown a higher level in restenosis patients than non-restenosis patients and even primary patients who accepted first stent therapy. In serum, different from some nonspecific and downstream inflammatory factors, TLR3 and TLR4 also show a significantly higher level in ISR group compared with N-ISR group and primary group. This study provides a potential clinical biomarker for in-stent restenosis in drug-stent patients and some interesting data about the role of TLRs and their downstream signaling factors in the inflammatory process of in-stent restenosis. Compared with first stent therapy and non-restenosis patients, it is hopeful that TLR3 and TLR4 are potential noninvasive biomarkers in prognosis restenosis.