hirudin and Neointima

Residual stent strut thrombosis after primary percutaneous coronary intervention (PCI), negatively affects myocardial perfusion, may increase stent thrombosis risk, and it is associated with neointima hyperplasia at follow-up.. To study the effectiveness of any bivalirudin infusion versus unfractionated heparin (UFH) infusion in reducing residual stent strut thrombosis in patients with ST-elevation myocardial infarction (STEMI).. Multi-vessel STEMI patients undergoing primary PCI and requiring staged intervention were selected among those randomly allocated to two different bivalirudin infusion regimens in the MATRIX (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and angioX) Treatment-Duration study. Those receiving heparin only were enrolled into a registry arm. Optical coherence tomography (OCT) of the infarct-related artery was performed at the end of primary PCI and 3-5 days thereafter during a staged intervention. The primary endpoint was the change in minimum flow area (ΔMinFA) defined as (stent area + incomplete stent apposition [ISA] area) - (intraluminal defect + tissue prolapsed area) between the index and staged PCI.. 123 patients in bivalirudin arm and 28 patients in the UFH arm were included. Mean stent area, percentage of malapposed struts, and mean percent thrombotic area were comparable after index or staged PCI. The ΔMinFA in the bivalirudin group was 0.25 versus 0.05 mm. The administration of bivalirudin after primary PCI significantly reduces residual stent strut thrombosis when compared to UFH. This observation should be considered hypothesis-generating since the heparin-treated patients were not randomly allocated.

Topics: Aged; Anticoagulants; Antithrombins; Coronary Thrombosis; Female; Hemorrhage; Heparin; Hirudins; Humans; Infusions, Parenteral; Italy; Male; Middle Aged; Neointima; Peptide Fragments; Percutaneous Coronary Intervention; Predictive Value of Tests; Prospective Studies; Recombinant Proteins; ST Elevation Myocardial Infarction; Stents; Time Factors; Tomography, Optical Coherence; Treatment Outcome

The aim of this study was to investigate the effects of bivalirudin on endothelial cell proliferation and neointimal hyperplasia in a rabbit carotid artery model.. "New Zealand rabbits (n = 12)" weighing 2-3 kg were randomly divided into two groups. Arteriotomy was performed to the rabbit carotid artery and closed with continuous suture technique. Group B (n = 6) as a control group received 150 U/kg heparin sodium; however, group A (n = 6) was given 0.75 mg/kg bivalirudin i.v. bolus and infusion 1.75 mg/kg/hour (B01AE06-Bivalirudin 250 mg) during perioperation period. At the end of the 28th day, the carotid artery segment was excised and evaluated histologically.. All histological and immune staining analyzes were performed by two blind researchers in the treatment of rabbits. In the control group rabbit carotid artery sections, tunica intima was observed to thicken. In the bivalirudin group, intimal hyperplasia was less observed compared to the control group. No significant difference was observed between groups in tunica media thickness. Lumen diameter and lumen area were found to be wider in the experimental group. P value was found to be less than 0.05.. Our study demonstrates that bivalirudin significantly affects and prevents neointimal hyperplasia and endothelial cell proliferation.

Topics: Animals; Cell Proliferation; Hirudins; Hyperplasia; Neointima; Peptide Fragments; Rabbits; Recombinant Proteins; Tunica Intima

General physicochemical properties of the vascular grafts (VGs) produced from the solutions of Tecoflex (Tec) with gelatin (GL) and bivalirudin (BV) by electrospinning are studied. The electrospun VGs of Tec-GL-BV and expanded polytetrafluoroethylene (e-PTFE) implanted in the abdominal aorta of 36 Wistar rats have been observed over different time intervals up to 24 weeks. A comparison shows that 94.5% of the Tec-GL-BV VGs and only 66.6% of e-PTFE VGs (р = 0.0438) are free of occlusions after a 6 month implantation. At the intermediate observation points, Tec-GL-BV VGs demonstrate severe neovascularization of the VG neoadventitial layer as compared with e-PTFE grafts. A histological examination demonstrates a small thickness of the neointima layer and a low level of calcification in Tec-GL-BV VGs as compared with the control grafts. Thus, polyurethane-based protein-enriched VGs have certain advantages over e-PTFE VGs, suggesting their utility in clinical studies.

Topics: Animals; Aorta, Abdominal; Biocompatible Materials; Biomechanical Phenomena; Blood Vessel Prosthesis; Chemical Phenomena; Female; Gelatin; Hirudins; Male; Materials Testing; Models, Animal; Neointima; Peptide Fragments; Polytetrafluoroethylene; Polyurethanes; Rats; Rats, Wistar; Recombinant Proteins