Permanent polymer of drug eluting stents increases eosinophil cationic protein levels following percutaneous coronary intervention independently of C-reactive protein.

AIM: To assess eosinophil cationic protein (ECP) and C-reactive protein (CRP) serum levels at three time points according to different stent types. METHODS: 54 patients (age 64 ± 10 years, male 78%), undergoing Bare Metal Stent (BMS) (n = 11), mammalian Target Of Rapamycin (mTOR)-inhibitor DES (n = 27) and mTOR-inhibitor bioabsorbable DES (BES) (n = 16) implantation for stable angina (SA) or non-ST-elevation acute coronary syndromes (NSTE-ACS), were prospectively enrolled. ECP and CRP serum levels were assessed before revascularization, at 1-month and at 1-year after the procedure. Moreover, 21 patients found to have inducible ischemia or angina symptoms at 6 month-stress test underwent 1-year follow-up (FU) angiography. RESULTS: Baseline and 1-month ECP levels were similar among the 3 groups, whilst 1-year ECP was significantly higher in m-TOR-DES [8.61 (6.55-19.77) µg/ml] compared with m-TOR-BES [2.03 (1.78-5.53) µg/ml] and BMS-treated patients [2.23 (1.45-8.95) µg/ml] (p = 0.02), without significant difference between BES and BMS. CRP was similar among the 3 groups at all time points. 1-year ECP significantly correlated with late loss in patients undergoing FU angiography (r = 0.64, p = 0.002), while CRP did not (p = NS). CONCLUSIONS: Our finding suggests that mTOR-DES stent type is associated with an increase of ECP levels at 1-year, possibly reflecting a persistent eosinophil activation triggered by permanent polymer.

Association between inflammatory biomarkers and in-stent restenosis tissue features: an Optical Coherence Tomography Study.

AIMS: Inflammatory reaction after stent implantation is associated with in-stent restenosis (ISR). We assessed the association of optical coherence tomography (OCT) features of neointima with systemic levels of high-sensitivity C-reactive protein (hs-CRP) and eosinophil cationic protein (ECP) measured at the time of ISR detection. METHODS AND RESULTS: Patients presenting with symptomatic angiographically documented ISR (diameter stenosis ≥ 50% by visual estimation) were included. Quantitative OCT analysis included the measurement of minimal lumen diameter, minimal luminal area, stent and neointimal area, stent and restenosis length, restenotic tissue burden, and symmetry ratio. Qualitative OCT analysis included the assessment of ISR plaque type, neointimal tissue structure, lumen shape, presence of microvessels and calcific nodules. At the time of ISR detection hs-CRP and ECP levels were measured, and statistical analysis was performed using as cut-off 3 mg/L and 4.5 µg/L, respectively. Our population included 40 patients, 24 bare metal stents and 16 drug-eluting stents. Patients with high hs-CRP levels had a higher restenostic tissue symmetry ratio (0.56 ± 0.17 vs. 0.42 ± 0.13, P = 0.01) when compared with patients with low hs-CRP levels. Patients with high ECP levels had a higher neointimal burden (70 ± 14 vs. 64 ± 11, P = 0.05) in comparison with patients with low ECP levels. CONCLUSIONS: Inflammatory biomarkers assessed at the time of ISR detection are associated with different aspects of neointimal tissue. While hs-CRP seems to have a role in neointimal tissue shape, ECP is related to a neointimal burden.

In-stent restenosis after revascularization of myocardium with drug-eluting stents is accompanied by elevated level of blood plasma eosinophil cationic protein.

The aim of this study was to assess the involvement of eosinophil cationic protein, a marker of eosinophil activation, in the development of in-stent restenosis after drug-eluting stent implantation. Follow-up angiography at 6 to 12 months was performed in 32 patients who were treated with percutaneous coronary intervention and implantation of sirolimus-eluting stents. Blood plasma levels of eosinophil cationic protein (ECP) and total immunoglobulin E (IgE) were measured by enzyme-linked immunosorbent assay and the level of C-reactive protein (hs-CRP) by high-sensitivity nephelometry. According to angiography data, in-stent restenosis occurred in 13 patients, while 19 patients did not develop it. There were no differences between the hs-CRP and IgE levels in patients with or without restenosis. In contrast, ECP level was higher in patients with restenosis compared with that in patients without restenosis [17.7 ng/mL (11.2-24.0) vs. 9.0 ng/mL (6.4-12.9), p = 0.017]. The incidence of in-stent restenoses was 63% in patients with ECP level higher than or equal to 11 ng/mL, and 19% in patients with an ECP level lower than 11 ng/mL (p = 0.019). These findings suggest that elevated eosinophil activation may play an important role in the pathogenesis of in-stent restenosis after implantation of drug-eluting stents.