Qualitative Improvement of a Coronary Plaque after Treatment with a Strong Statin : Observation using Virtual Histology Intravascular Ultrasound

Statins are used currently for treatment and prevention of coronary artery disease, but it is difficult to assess the therapeutics effects and patient responses to different statins. Virtual histology intravascular ultrasound (VH-IVUS) has been used to evaluate detailed quantitative changes in coronary plaques, and here we report a case in which marked qualitative improvement in a coronary plaque was observed using VH-IVUS after a change in treatment from a conventional statin to a strong statin

Impact of Neointimal Calcifications on Acute Stent Performance during the Treatment of In-Stent Restenosis

Abstract Optical coherence tomography (OCT) has become the invasive imaging modality of choice for coronary stent assessment due to its unmatched spatial resolution. Neointimal calcification (NC) is a rare finding, observed in 5-10% of in-stent restenosis (ISR) neointima. The impact of NC on percutaneous coronary intervention of ISR is unknown. We therefore present the outcome of six unique cases of ISR and NC in which OCT was used to evaluate the impact of NC on the quality of stent-in-stent deployment for the treatment of ISR. This series demonstrates for the first time the impact of NC on stent expansion, a finding which might help guiding percutaneous coronary intervention for ISR with NC

Effects of the factor Xa inhibitor rivaroxaban on the differentiation of endothelial progenitor cells

Abstract Background We evaluated the efficacy of the factor Xa inhibitor rivaroxaban on the differentiation ability of vascular endothelial progenitor cells (EPCs), which play roles in vascular injury repair and atherogenesis. Antithrombotic treatment in patients with atrial fibrillation undergoing percutaneous coronary intervention (PCI) is challenging, and current guidelines recommend oral anticoagulant monotherapy 1 year or more after PCI. However, biological evidence of the pharmacological effects of anticoagulants is insufficient. Methods EPC colony-forming assays were performed using peripheral blood-derived CD34-positive cells from healthy volunteers. Adhesion and tube formation of cultured EPCs were assessed in human umbilical cord-derived CD34-positive cells. Endothelial cell surface markers were assessed using flow cytometry, and Akt and endothelial nitric oxide synthase (eNOS) phosphorylation were examined using western blot analysis of EPCs. Adhesion, tube formation and endothelial cell surface marker expression was observed in EPCs transfected with small interfering RNA (siRNA) against protease-activated receptor (PAR)-2. Finally, EPC behaviors were assessed in patients with atrial fibrillation undergoing PCI in whom warfarin was changed to rivaroxaban. Results Rivaroxaban increased the number of large EPC colonies and increased the bioactivities of EPCs, including adhesion and tube formation. Rivaroxaban also increased vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, Tie-2, and E-selectin expression as well as Akt and eNOS phosphorylation. PAR-2 knockdown increased the bioactivities of EPCs and endothelial cell surface marker expression. Patients in whom the number of large colonies increased after switching to rivaroxaban showed better vascular repair. Conclusions Rivaroxaban increased the differentiation ability of EPCs, leading to potential advantages in the treatment of coronary artery disease

Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

Background: Bone marrow-derived progenitor cells likely contribute to both endothelial- and smooth muscle cell-dependent healing responses in stent-injured vessel sites. This study aimed to assess mobilization of progenitor cells and vessel healing after zotarolimus-eluting (ZES) and everolimus-eluting (EES) stents. Methods and results: In 63 patients undergoing coronary stent implantation, we measured circulating CD34+CD133+CD45low cells and serum levels of biomarkers relevant to stem cell mobilization. In 31 patients of them, we assessed vessel healing within the stented segment using optical coherence tomography (OCT) imaging. The CD34+CD133+CD45low cells increased 68 ± 59% 7 days after bare metal stent (BMS), 10 ± 53% after ZES (P < 0.01 vs BMS), 3 ± 49% after EES (P < 0.001 vs BMS), compared with baseline. Percent change in CD34+CD133+CD45low cells was positively correlated with that in stromal cell-derived factor (SDF)-1α (R = 0.29, P = 0.034). Percentage of uncovered struts was higher in the EES group (14.4 ± 17.3%), compared with the BMS (0.7 ± 1.3, P < 0.01) and ZES (0.4 ± 0.5, P < 0.01) groups. The change in CD34+CD133+CD45low cells showed positive correlation with OCT-quantified mean neointimal area (R = 0.48, P < 0.01). Finally, circulating mononuclear cells obtained from 5 healthy volunteers were isolated to determine the effect of sirolimus, zotarolimus and everolimus on vascular cell differentiation. The differentiation of mononuclear cells into endothelial-like cells was dose-dependently suppressed by sirolimus, zotarolimus, and everolimus. Conclusions: Mobilization of progenitor cells was suppressed, and differentiation of mononuclear cells into endothelial-like cells was inhibited, in association with increased number of uncovered stent struts, even after second generation drug-eluting stenting. These data suggest that new approaches are necessary to enhance stent healing. Keywords: Drug-eluting stent, Vascular injury, Circulating progenitor cell, Re-endothelialization, Optical coherence tomograph

New Volumetric Analysis Method for Stent Expansion and its Correlation With Final Fractional Flow Reserve and Clinical Outcome: An ILUMIEN I Substudy

This study sought to compare conventional methodology (CM) with a newly described optical coherence tomography (OCT)-derived volumetric stent expansion analysis in terms of fractional flow reserve (FFR)-derived physiology and device-oriented composite endpoints (DoCE)