Effects of cytochalasin D-eluting stents on intimal hyperplasia in a porcine coronary artery model.

Objective: To investigate whether cytochalasin D-eluting stents (CDES) suppress intimal hyperplasia in porcine coronary arteries and to compare the efficacy of paclitaxel and cytochalasin D as inhibitors of vascular smooth muscle cell (SMC) proliferation and platelet aggregation in vitro.

Methods: Rabbit platelet-rich plasma and SMC cultures derived from rabbit aortas were exposed to 10(-8)-10(-5) M cytochalasin D or paclitaxel. Stents directly coated with 2 microg cytochalasin D (low-dose CDES, n=12) and bare stents (n=12) were randomly deployed in the right and left coronary artery of 12 pigs.

Addition of cytochalasin D to a biocompatible oil stent coating inhibits intimal hyperplasia in a porcine coronary model.

Background: Polymer-based, drug-eluting stents, are currently under extensive investigation in the conquest against in-stent restenosis. Concern remains, however, about potential long-term lack of biocompatibility of the polymers used in these studies. Therefore, this study aimed to evaluate in porcine coronary arteries (1) the in vivo biocompatibility of a new natural, eicosapentaenoic acid oil stent-coating and (2) the efficacy of this coating in preventing in-stent restenosis when cytochalasin D--an inhibitor of actin filament formation, that interferes with cell proliferation and migration--was added.

Long term effects of nisoldipine on the progression of coronary atherosclerosis and the occurrence of clinical events: the NICOLE study.

Background: Earlier angiographic studies have suggested that calcium antagonists may prevent the formation of new coronary lesions and the progression of minimal lesions. Conversely, a meta-analysis suggested that these drugs may increase cardiovascular mortality and morbidity in patients with coronary heart disease.

Objective: To investigate whether nisoldipine retards the progression of coronary atherosclerosis or reduces the occurrence of clinical events.

Optimal dosing of intravascular low-power red laser light as an adjunct to coronary stent implantation: insights from a porcine coronary stent model.

Background: It is believed that restenosis following coronary interventions is the result of endothelial denudation that leads to thrombus formation, vascular remodeling, and smooth muscle cell proliferation. Low-power red laser light (LPRLL) irradiation enhances endothelial cell growth in vitro and in vivo, and reduces restenosis in animal models. The present study investigated the optimal dose of intravascular LPRLL therapy in the prevention of in-stent stenosis in a porcine coronary stent model.

Intravascular low-power laser irradiation after coronary stenting: long-term follow-up.

Background And Objective: A high restenosis rate remains a limiting factor for percutaneous transluminal coronary angioplasty and stenting. The objective of this study was to evaluate the effect of intravascular red laser therapy (IRLT) on restenosis after stenting procedures in de novo lesions.

Study Design/materials And Methods: A total of 68 consecutive patients were treated with IRLT in conjunction with coronary stenting procedures.

Intravascular low-power red laser light as an adjunct to coronary stent implantation: initial clinical experience.

Low-power red laser light (LPRLL) irradiation enhances endothelial cell growth in vitro and in vivo and reduces restenosis in animal models. The present study reports the preliminary clinical experience in our center. Eighty-one patients were treated with LPRLL, 30 mW/1 min, for in-stent restenosis (n = 27), elective stenting for recurrent restenosis (n = 16), and stenting for treatment of a suboptimal PTCA result (n = 38).

Usefulness of Nisoldipine for prevention of restenosis after percutaneous transluminal coronary angioplasty (results of the NICOLE study). NIsoldipine in COronary artery disease in LEuven.

The NIsoldipine in COronary artery disease in LEuven (NICOLE) study investigates (1) whether nisoldipine, a dihydropyridine calcium antagonist, reduces the progression of minor coronary arterial lesions in the long term, and (2) whether it reduces the restenosis rate after successful percutaneous transluminal coronary angioplasty (PTCA). The NICOLE study is a single-center, randomized, double-blind trial in 826 patients, who underwent a successful PTCA. Nisoldipine 40 mg coat-core or placebo was started the morning after the procedure and continued for 3 years.

Experimental Evaluation of a New Tubular Coronary Stent (V-Flexª).

The safety, efficacy, angiographic and histological effects of a new 316 L, SS seamless stainless steel tubular stent (V-Flexª, Global Therapeutics, Broomfield, Colorado) was evaluated in a porcine coronary and peripheral artery model. Implantation in the right coronary artery was successful in all 16 pigs. Eight pigs were angiographically controlled after 6 weeks and then sacrificed for morphometric analysis.

Intravascular Low Power Red Laser Light as an Adjunct to Coronary Stent Implantation Evaluated in a Porcine Coronary Model.

BACKGROUND: It is believed that restenosis following coronary interventions is the result of endothelial denudation that leads to thrombus formation, vascular remodeling, and smooth muscle cell proliferation. We previously demonstrated that low power red laser light (LPRLL) irradiation enhances endothelial cell growth in vitro and in vivo and reduces restenosis in a small animal model. The present study investigated the effectiveness of intravascular LPRLL therapy in the reduction of restenosis following stenting in a porcine model.

Stent Deployment Pressure Defines the Stent/Vessel Wall Relationship and has Important Implications for Early and Late Outcome.

OBJECTIVE: This study evaluates the effect of stent deployment pressure on stent deployment, coronary vessel injury, subacute reclosure and foreign body reaction in a porcine coronary model. METHODS: Stainless steel coil stents were deployed in the right coronary artery of 30 pigs either using a deployment pressure of 4 atm (group I), 8 atm (group II), or 14 atm (group III). Serial quantitative angiographic studies together with morphometric analysis of the stented vessels were performed.

Experimental Evaluation of a New Single Wire Tantalum Coil Coronary Stent (Wiktor-iª).

To improve scaffolding properties, a new more densely woven Wiktor stent, the Wiktor-iª stent, was developed. Although the metal coverage remains still low compared to other stents, increased metal/vessel area raises the concern of increased thrombogenicity and neointimal hyperplasia. In this study we evaluated the Wiktor-i stent in a porcine peripheral and coronary model and compared the thrombogenicity and neointimal hyperplasia with the Wiktor-GX coronary stent.

Treatment of long dissections by use of a single long or multiple short stents: clinical and angiographic follow-up.

Background: Recently, long (> or =20 mm) coronary stents were introduced for clinical use. They are intended as an alternative to multiple conventional stents to treat extensive dissections or suboptimal results of long lesions after balloon angioplasty.

Methods: In a total of 113 such consecutive vessels in 107 patients, the flexible Freedom stent was implanted.

Clinical and angiographic outcome after implantation of a home-made stent for complicated coronary angioplasty.

To defray the escalating costs of coronary stenting, we handmade a balloon-expandable, stainless steel stent, which after experimental evaluation, was implanted in 156 patients undergoing PTCA complicated by a major dissection. The procedural success rate was 98%. The in-hospital course was characterized by a 1.

Comparison of clinical complications, angiographic results, and device usage of coronary angioplasty using low- and high-compliance balloons.

We randomized 800 patients in a prospective study comparing the angiographic results, device usage and in-hospital outcome of balloon angioplasty of primary stenoses of native coronary vessels with low-compliant and highly compliant balloons. The cumulative incidence of prespecified clinical endpoints was 8.0% in both treatment groups.

Clinical and Angiographic Experience with Coronary Stenting Using Freedomª Stent.

The immediate safety and efficacy and the 6 month clinical and angiographic follow-up of a new fish-scale designed coronary coil stainless steel stent (Freedomª) was assessed by a prospective study. During 1995, 169 patients were treated on 177 vessels using 233 Freedom stents. Procedural indication for stenting was a bail-out situation in 79 vessels, a suboptimal angioplasty result in 62 vessels and a third restenosis after PTCA in 36 vessels.

Experimental Evaluation of a New Single Wire Stainless Steel Fishscale Coronary Stent (Freedomª).

Recent randomized clinical trials revealed a significant reduction in angiographic restenosis rates when adjunctive stenting was performed after conventional coronary balloon angioplasty. Current approved coronary stents are however hampered by their rigidity, limiting their trackability in tortuous vessels and furthermore, needing high pressure deployment for optimal vessel apposition. New coronary stents are currently under development, using more biocompatible metal alloys and/or designs which better align to the vessel wall at moderate deployment pressures.

Concept of the homemade coronary stent: experimental results and initial clinical experience.

To defray the escalating cost of coronary stenting, we handmade a balloon expandable coil stent with stainless steel wire. Preliminary comparison with the Palmaz-Schatz stent showed that, when implanted in porcine iliac arteries, there was no difference in immediate angiographic results or in the degree of foreign body reaction at 6 wk. Subsequently, a total of 73 stents were implanted in 52 patients, either as a bailout device (54%) or for suboptimal angiographic results (46%).

Biocompatibility of biodegradable and nonbiodegradable polymer-coated stents implanted in porcine peripheral arteries.

Purpose: To investigate the neointimal response to poly(organo)phosphazene- and amphiphilic polyurethane-coated, oversized, stainless steel stents implanted in porcine peripheral arteries.

Methods: Nonarticulated, stainless steel, slotted-tube stents were coated with 1) a biodegradable poly-(organo)phosphazene with aminoacid ester side groups and 2) a biostable polyurethane prepared from an amphiphilic polyether, diphenyl methane-4,4'-diisocyanate and butane diol as chain extender. The stents were deployed in porcine peripheral arteries using an oversized balloon.

Characteristics of creatine release during acute myocardial infarction, unstable angina, and cardiac surgery.

Creatine release was compared in various conditions of muscle damage: acute myocardial infarction (AMI), unstable angina, and cardiac surgery. After AMI, serum and urine creatine concentrations increased transiently. After cardiopulmonary resuscitation, serum creatine values were significantly higher because of impaired renal function, whereas urinary creatine concentrations were comparable.

Biocompatibility of polymer-coated oversized metallic stents implanted in normal porcine coronary arteries.

Polymer coatings have been suggested to decrease the thrombogenicity of metallic intravascular stents. The purpose of the present study was to investigate the intimal response to two different polymers when used as coatings for stents implanted in normal porcine coronary arteries. Non-articulated stainless steel-slotted tube stents were coated with either a biodegradable poly(organo)phosphazene with amino-acid ester side groups or a biostable polyurethane prepared from an amphiphilic polyether, dephenylmethane-4,4'-diisocyanate and butane diol as chain extender.

Intraarterial biocompatibility of polyethylene terephthalate self-expandable stents implanted in porcine peripheral arteries.

Rationale And Objectives: We tested deployment feasibility and intraarterial biocompatibility of polyethylene terephthalate (PET) self-expandable vascular stents in a porcine peripheral artery model.

Methods: To assess the thrombogenicity and neointimal response to oversized PET self-expandable stents, we implanted 10 stents in porcine common iliac arteries, followed by a 6-mm balloon inflation to 6 atm.

Results: All pigs survived until the study termination 6 weeks after stent implantation.

The 'Ermenonville' classification of observations at coronary angioscopy--evaluation of intra- and inter-observer agreement. European Working Group on Coronary Angioscopy.

A European coronary angioscopy working group has been established to create and evaluate a classification system for angioscopic observation. The 'Ermenonville' classification features items, graded in 3-5 categories, such as lumen diameter, shape of narrowing, colours of surface, atheroma, dissection, thrombus, etc. Inter- and intra-observer agreement on the interpretation of angioscopic images, using this classification system, was studied within the working group.

Immediate and 6-month follow-up results of coronary angioplasty for restenosis: analysis of factors predicting recurrent clinical restenosis.

To determine the results of coronary angioplasty for a first restenosis, the clinical, anatomic, and procedural data of 400 consecutive patients were compared with the data of 507 consecutive patients undergoing a first angioplasty. After angioplasty for restenosis, emergency redilatation had to be performed in only 0.7% of the patients versus 3.

Cardiac ATP breakdown and mechanical function during recurrent periods of anoxia.

The effect of repeated short anoxic or ischemic periods on ATP breakdown and cardiac function remains controversial. To analyze this issue further and to study the regulation of adenine nucleotide breakdown during recurrent cardiac anoxia, we compared two different protocols of intermittent anoxia. Four rat hearts, perfused according to Langendorff, were exposed to 12 periods of anoxia, each lasting 1 minute, with reoxygenation periods of 3 minutes (protocol A).

Stenting of venous bypass grafts: a new treatment modality for patients who are poor candidates for reintervention.

During a 2-year period, 136 self-expanding Wallstents were implanted in saphenous vein bypass grafts in 69 patients with end-stage coronary artery disease. All patients had severe symptoms and the majority were poor candidates for either repeat surgery or conventional bypass coronary angioplasty because of unfavorable native anatomy, impaired left ventricular function, or a high-risk bypass lesion anatomy for coronary angioplasty. All procedures were technically successful without major complications and a need for emergency bypass surgery.