9-year clinical follow-up of patients with ST-segment elevation myocardial infarction with Genous or TAXUS Liberté stents

Intraprocedural endothelial cell seeding of arterial stents via biotin/avidin targeting mitigates in-stent restenosis

Impaired endothelialization of endovascular stents has been established as a major cause of in-stent restenosis and late stent thrombosis. Attempts to enhance endothelialization of inner stent surfaces by pre-seeding the stents with endothelial cells in vitro prior to implantation are compromised by cell destruction during high-pressure stent deployment. Herein, we report on the novel stent endothelialization strategy of post-deployment seeding of biotin-modified endothelial cells to avidin-functionalized stents. Acquisition of an avidin monolayer on the stent surface was achieved by consecutive treatments of bare metal stents (BMS) with polyallylamine bisphosphonate, an amine-reactive biotinylation reagent and avidin. Biotin-modified endothelial cells retain growth characteristics of normal endothelium and can express reporter transgenes. Under physiological shear conditions, a 50-fold higher number of recirculating biotinylated cells attached to the avidin-modified metal surfaces compared to bare metal counterparts. Delivery of biotinylated endothelial cells to the carotid arterial segment containing the implanted avidin-modified stent in rats results in immediate cell binding to the stent struts and is associated with a 30% reduction of in-stent restenosis in comparison with BMS.

Coronary stent CD31-mimetic coating favours endothelialization and reduces local inflammation and neointimal development in vivo

AIMS

The rapid endothelialization of bare metal stents (BMS) is counterbalanced by inflammation-induced neointimal growth. Drug-eluting stents (DES) prevent leukocyte activation but impair endothelialization, delaying effective device integration into arterial walls. Previously, we have shown that engaging the vascular CD31 co-receptor is crucial for endothelial and leukocyte homeostasis and arterial healing. Furthermore, we have shown that a soluble synthetic peptide (known as P8RI) acts like a CD31 agonist. The aim of this study was to evaluate the effect of CD31-mimetic metal stent coating on the in vitro adherence of endothelial cells (ECs) and blood elements and the in vivo strut coverage and neointimal growth.

METHODS AND RESULTS

We produced Cobalt Chromium discs and stents coated with a CD31-mimetic peptide through two procedures, plasma amination or dip-coating, both yielding comparable results. We found that CD31-mimetic discs significantly reduced the extent of primary human coronary artery EC and blood platelet/leukocyte activation in vitro. In vivo, CD31-mimetic stent properties were compared with those of DES and BMS by coronarography and microscopy at 7 and 28 days post-implantation in pig coronary arteries (n = 9 stents/group/timepoint). Seven days post-implantation, only CD31-mimetic struts were fully endothelialized with no activated platelets/leukocytes. At day 28, neointima development over CD31-mimetic stents was significantly reduced compared to BMS, appearing as a normal arterial media with the absence of thrombosis contrary to DES.

CONCLUSION

CD31-mimetic coating favours vascular homeostasis and arterial wall healing, preventing in-stent stenosis and thrombosis. Hence, such coatings seem to improve the metal stent biocompatibility.

Surface grafting of Fc-binding peptides as a simple platform to immobilize and identify antibodies that selectively capture circulating endothelial progenitor cells

Antibody surface immobilization is a promising strategy to capture cells of interest from circulating fluids in vitro and in vivo. An application of particular interest in vascular interventions is to capture endothelial progenitor cells (EPCs) on the surface of stents to accelerate endothelialization. The clinical impact of EPC capture stents has been limited by the lack of efficient selective cell capture. Here, we describe a simple method to immobilize a variety of immunoglobulin G antibodies through their fragment crystallizable (Fc) regions via surface-conjugated RRGW peptides for cell capture applications. As an EPC capture model, peripheral blood endothelial colony-forming cells suspended in cell culture medium with up to 70% serum were captured by immobilized anti-CD144, anti-CD34 or anti-CD309 antibodies under laminar flow. The endothelial colony-forming cells were successfully enriched from a mixture with peripheral blood mononuclear cells using surfaces with anti-CD309 but not anti-CD45. This antibody immobilization approach holds great promise to engineer vascular biomaterials with improved EPC capture potential. The ease of immobilizing different antibodies using the same Fc-binding peptide surface grafting chemistry renders this platform suitable to screen antibodies that maximize cell capture efficiency and selectivity.

[Percutaneous Coronary Interventions in Patients With ST-Elevation Myocardial Infarction: 10-Years Follow-up]

Aim      To study long-term results and to identify predictors of death in patients with ST-segment elevation acute myocardial infarction (STEMI) who underwent endovascular revascularization.Materials and methods This study included 283 patients registered in the hospital registry of percutaneous coronary interventions (PCI) for STEMI from 2006 through 2009. Analysis of 10-year results included all-cause and cardiovascular death rate, incidence of recurrent myocardial infarction (MI), repeated revascularization, stroke, stent restenosis and thrombosis. Also, a composite endpoint МАССЕ (Major Adverse Cardiovascular and Cerebrovascular Events) was evaluated, which included death, recurrent MI, repeated PCI, stent restenosis and thrombosis, coronary bypass, and stroke.Results Information about the health condition was provided by 204 (72.1 %) patients. Mean follow-up period was 120.1±9.5 months. All-cause mortality was 25.5 % with cardiovascular death determined in 19.1 % of cases. Recurrent MI developed in 21.6 % of patients; in 1.5 % of cases, recurrent MI resulted from thrombosis of previously implanted stents. Repeated PCI was performed for 31.9 % of patients; in 13.7 % of cases, the PCI was performed for stent restenosis. Coronary bypass was performed for 5.4 % of patients. Incidence of stroke was 10.3 %. Major cardiovascular and cerebrovascular complications (МАССЕ) during the follow-up period were determined in 60.3 % patients. According to the Cox proportional hazards regression model, age ≥65 years (odds ratio (OR), 3.75 at 95 % confidence interval (CI) from 1.75 to 8.03; р=0.001) and incomplete coronary revascularization (OR, 3.09 at 95 % CI from 1.52 to 6.30; р=0.002) were independent predictors of death based on data of the 10-year observation.Conclusion      Therefore, at 10 years following endovascular revascularization, STEMI patients showed a moderate death rate with a high incidence of major cardiovascular and cerebrovascular complications. The leading causes for fatal outcomes were recurrent cardiovascular complications. The major predictors of death for the coming 10-year period included age ≥65 years and incomplete myocardial revascularization.