Catheter Cardiovasc Interv
November 2007
Objectives And Background: The purpose of this study was to determine the effectiveness and vascular response of a pimecrolimus drug eluting stent and a combination (pimecrolimus + paclitaxel) stent as compared with bare metal controls in the porcine coronary model.
Methods And Results: In the first phase of the study, cobalt chromium stents were loaded with an erodible polymer and either a slow release or a fast release formulation of pimecrolimus. Thirty stents (metal, n = 10; pimecrolimus slow, n = 10; pimecrolimus fast, n = 10) were implanted in the coronary arteries of 10 pigs.
Background: The CoStar stent is a novel cobalt chromium stent designed specifically for drug delivery. The COSTAR I trial represents the first-in-man study of the CoStar Paclitaxel-Eluting Coronary Stent System evaluating three dose release formulations of paclitaxel in a bioresorbable polymer matrix in the treatment of de novo coronary lesions.
Methods: The COSTAR I Trial was a prospective, multi-center registry enrolling 87 patients in four Indian centers for treatment of up to two de novo lesions = 25 mm in length in a reference vessel 2.
Aims: Paclitaxel is a potent and effective inhibitor of neointimal proliferation after coronary stenting. The Conor stent loaded with Paclitaxel can be programmed with multi-parameter matrix of dose, temporal release profiles and release pathways. The aim of this study was to determine the most efficacious dose and release pattern of Paclitaxel in a porcine model and parallels the PISCES trial.
View Article and Find Full Text PDFAims: The one year clinical benefit of various doses and release durations of paclitaxel eluted from an erodable polymer has not been evaluated so far.
Methods And Results: Conor paclitaxel-eluting stents have intra-stent wells in which drug and polymer are deposited. Stents with six different release formulations (dose: 10 microg or 30 microg, duration: 5, 10 or 30 days, direction: mural or bidirectional) were implanted in 6 patient cohorts.
Objectives: The aim of this study was to evaluate the effect of variable dose and release kinetics of paclitaxel on neointimal hyperplasia.
Background: Conventional paclitaxel-eluting stents use a durable polymer coating as a vehicle for drug delivery. The Conor stent (Conor Medsystems, Menlo Park, California) with intra-strut wells and erodable polymer is specifically designed for drug delivery with programmable pharmacokinetics.
Background: Fixed drug release kinetics and vessel wall partitioning may limit the effectiveness of drug-eluting stents. We report preliminary experience using a new coronary stent with programmable pharmacokinetics.
Methods And Results: A newly designed metallic stent contains honeycombed strut elements with inlaid stacked layers of drug and polymer.
Background: The major limitation of coronary stenting is restenosis due to exaggerated neointimal thickening. We evaluated a positron-emitting V48 nitinol stent in a porcine coronary model of restenosis.
Methods And Results: Pigs (n = 16) received a control nonradioactive and a V48 stent (1.
Cardiovasc Radiat Med
April 2001
We are reporting the first case of an accidental radioactive 188Re leakage of a liquid-filled balloon system. Different analytical methods estimated that approximately 4 mCi 188Re were released. The radiation burden was reduced considerably by the combined therapy with perchlorate and forced volume diuresis.
View Article and Find Full Text PDFCardiovasc Radiat Med
January 2001
We are reporting the first case of an accidental radioactive 188Re leakage of a liquid-filled balloon system. Different analytical methods estimated that approximately 4 mCi 188Re were released. The radiation burden was reduced considerably by the combined therapy with perchlorate and forced volume diuresis.
View Article and Find Full Text PDFBackground: Restenosis within stents may be prevented by ionizing radiation from an intravascular source.
Methods And Results: A liquid beta(-) radiation ((188)Re) balloon was evaluated in a randomized and blinded porcine coronary model of stent restenosis. Group A pigs (n=17) received 0,16, 22, or 29 Gy at 0.
The efficacy of abciximab and moderate dose heparin in attaining reperfusion in acute MI was tested in a multicenter pilot study. Patients with acute MI of less than 6-hr onset triaged to primary PTCA received intravenous abciximab bolus and infusion and heparin (70 u/kg) in the emergency room. Mean time to angiography from administration of abciximab was 34 +/- 23 min.
View Article and Find Full Text PDFBackground: Stent-induced coronary restenosis is a major clinical and public health problem. Proliferating cell nuclear antigen (PCNA) is an important regulator of cell division, and blocking of its expression after angioplasty may limit intimal proliferation.
Methods And Results: We cloned the porcine PCNA gene and constructed a chimeric hammerhead ribozyme to a segment of the gene with human homology.
Aims: Use of ticlopidine in coronary stenting is limited by delayed onset of action. We studied the effects of clopidogrel, a rapidly acting analog of ticlopidine alone, and in combination with aspirin, in inhibiting stent thrombosis.
Methods: Unpolished nitinol stents were deployed in a porcine ex vivo arteriovenous shunt and exposed to flowing arterial blood at a shear rate of approximately 1500.
Cathet Cardiovasc Diagn
October 1998
To assess the arterial injury triggered by polyurethane-coated vs. uncoated stents, six polyurethane-coated and six bare nitinol stents were implanted in rabbit carotid arteries. All animals were sacrificed 4 wk after stent placement.
View Article and Find Full Text PDFThe Prima laser guidewire system (Spectranectics Corp., Colorado Springs, CO) consists of an 0.018" hypotube containing a bundle of 45-microm optical fibers coupled to a pulsed excimer laser operating at a tip fluence of 60 ml/mm2 and a repetition rate ranging from 25-40 Hz.
View Article and Find Full Text PDFPercutaneous transluminal coronary angioplasty (PTCA) is currently one of the most common treatments for obstructive coronary artery disease. The long term success of the treatment, however, is severely limited by restenosis. Recently, different investigators have begun to study the possibility of radiation therapy in restenosis prevention and have shown promising results.
View Article and Find Full Text PDFIn the New Approaches to Coronary Intervention (NACI) registry, 887 patients were electively treated with excimer laser coronary angioplasty (ELCA) for coronary artery disease. The Advanced Interventional System (AIS) system was used in 487 cases; the Spectranetics system, in 400. The mean age was 63.
View Article and Find Full Text PDFHigher complication rates and lower success rates for treatment of women compared with men have been reported in prior studies of coronary angioplasty and in most early reports of outcome with new coronary interventional devices. In multivariate analysis this has been attributed largely to older age and other unfavorable clinical characteristics. These results are reflected in the current guidelines for coronary angioplasty.
View Article and Find Full Text PDFJ Am Coll Cardiol
November 1997
Objectives: We sought to provide short- and long-term clinical outcomes of a high risk cohort treated with stents in saphenous vein grafts (SVGs).
Background: Data on the long-term outcome of SVG stenting in high risk patients are limited.
Methods: Johnson & Johnson stents were implanted in the SVGs of 186 patients (302 stents, 244 lesions).
Cathet Cardiovasc Diagn
July 1997
This study was designed to evaluate the feasibility of applying locally delivered polylactic acid microspheres for drug delivery to the arterial wall. To study drug persistence, rhodamine-loaded microspheres were infused into one carotid artery of 14 rabbits and plain rhodamine solution into the other by using a porous balloon. To study tissue response, plain microspheres and dexamethasone-loaded microspheres were infused into the carotid arteries of another group of rabbits.
View Article and Find Full Text PDFThe objective was to assess the arterial wall response to temporary stenting with a removable nitinol stent in comparison with permanent stenting and balloon injury at 28 days in the rabbit carotid artery. Restenosis remains an important limiting factor after the implantation of permanent metallic stents and balloon angioplasty. We have developed a temporary nitinol stent that uses a bolus injection of warmed saline to collapse the stent for percutaneous removal.
View Article and Find Full Text PDFBackground: Thrombosis is an important limitation of metallic coronary stents, especially in smaller vessels in which shear rates are high. Monoclonal antibody to platelet glycoprotein IIb/IIIa receptor (7E3) has been shown to inhibit shear-induced platelet aggregation. In this study, we compared the effects of 7E3, heparin, and aspirin on stent thrombosis in an ex vivo arteriovenous shunt model of high-shear blood flow.
View Article and Find Full Text PDFBackground: Coronary stenting is limited by subacute thrombosis, especially in smaller-diameter vessels, in which shear rates are high. The objective of the present study was to determine whether local delivery of a new type of NO donor, the NO adduct of N,N'-dimethylhexanediamine (DMHD/NO), inhibits acute stent thrombosis (ST) at high-shear flow.
Methods And Results: Effects of local infusion of DMHD/NO; intravenous aspirin, and heparin on ST were evaluated in an ex vivo porcine AV shunt model.
Background: Our objectives were to quantify the thrombogenicity and extent of vascular injury created by slotted-tube geometry stainless steel and nitinol coronary stents in a rabbit carotid artery model.
Methods And Results: Stents were implanted in rabbit right carotid arteries without antiplatelet therapy. Stainless steel stents were implanted for 4 days while nitinol stents were placed for 4 and 14 days (n = 8, 8, and 6, respectively).