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Drug Eluting Stents (drug + eluting_stent)
Selected AbstractsIntravascular bioresorbable polymeric stents: A potential alternative to current drug eluting metal stentsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2007Tahmer Sharkawi Abstract Stent implantation following angioplasty is the standard treatment of coronary artery disease necessitating interventional procedures. The use of stents as a platform for local drug delivery is a popular strategy to achieve local pharmacological treatment to the diseased artery. Drug eluting stents (DES) are now largely preferred to bare metal stents when stent implantation is necessary. Lately, there have been several reports questioning the long-term safety of DES. An alternative to these drug eluting metal stents are bioresorbable polymeric stents (BPS) because of the many advantages of bioresorbable material. However, the fundamental differences in polymeric and metallic materials make the development of such an alternative a significant challenge. This review discusses the different advantages of BPS and the many constrains and requirements of such devices. An up to date commented review of published data concerning BPS is presented. Considerations are given on using BPS as local drug delivery systems as well as on evaluating BPS performances. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 2829,2837, 2007 [source] Drug eluting stents for below the knee lesions in patients with critical limb ischemia,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2008Long-term follow-up Abstract Objectives: The purpose of this study was to assess the long-term limb preservation and/or healing of ulcers in patients with critical limb ischemia (CLI) and severe infrapopliteal atherosclerotic disease treated with drug eluting stents (DES). Background: Percutaneous revascularization has become an effective treatment for CLI in patients with infrapopliteal atherosclerotic disease. Recent reports using DES in patients with CLI have documented excellent short-term infrapopliteal vessel patency. Higher primary patency rates in infrapopliteal vessels treated with DES could translate into better long-term clinical outcomes and improved limb salvage rates. Methods: Twenty-four consecutive patients with CLI (defined as rest pain, nonhealing ulcers, or gangrene) because of severe infrapopliteal disease were treated with DES from August 2004 to June 2006. Results: Procedural success was achieved in 96% (27/28) of targeted lesions. There were no procedure-related deaths, acute vessel thrombosis events, or need for urgent surgical intervention. There was one case of distal embolization. Clinical follow up, ranging 8,34 months, is available for 100% of patients of which 83% (20/24) achieved limb preservation and healing. Angiographic and/or sonographic follow up, ranging 6,34 months, is available in 79% (19/24) of patients of which 95% (18/19) had patent target vessels. Conclusions: DES is a safe and effective long-term option for CLI due to severe infrapopliteal arterial disease. Long-term vascular patency led to a high rate of limb preservation and low amputation rate. A multicenter trial should further elucidate the role of DES in the treatment of CLI. © 2008 Wiley-Liss, Inc. [source] Controlled release of argatroban from PLA film,Effect of hydroxylesters as additives on enhancement of drug releaseJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Akira Mochizuki Abstract The aim of this study was to develop a drug eluting stent that prevents vein restenosis. For this, we selected argatroban as the study drug and poly(lactic acid) (PLA) as the matrix. To enhance the release of argatroban from PLA film, the addition of hydroxylesters (additives) was investigated. The additives investigated were diethyl tartrate (DET), diethyl malate (DEM), and triethyl citrate (TEC). Marked enhancement of drug release was observed in DET-added film, while TEC- or DEM-added film showed little enhancement. To clarify the effect of DET, the release profile based on the contents of the drug and DET in the film and the effect of alkyl chain length of tartrate were studied. Tartrates used were dimethyl, di- i -propyl, and di- n -butyl esters (DMT, DiPT, and DnBT, respectively), and the enhancement order was DMT , DET , DiPT , DBT , PLA alone. The reasons for enhancement were discussed from the viewpoint of drug release behavior, degradation of PLA, water uptake within the film, and SEM observations. It was concluded that enhancement of drug release was due to large amounts of water uptake within the film which resulted in the formation of open pores at its surface. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] The effect of drug eluting stents on cardiovascular events in patients with intermediate lesions and borderline fractional flow reserve,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2007Shahar Lavi MD Abstract Objective: To assess the role of fractional flow reserve (FFR) in guiding therapy in the drug eluting stent (DES) era. Background: FFR is a useful index for evaluation of the physiological significance of angiographically indeterminate coronary artery lesions. However, its role in the DES era is unknown. Methods: Long term outcome of 281 patients with angiographically indeterminate coronary lesions and borderline FFR (0.75 , FFR < 0.9) was obtained. The outcome of patients who had a DES placed (n = 58), was compared with that of consecutive patients with borderline FFR that were treated by PCI with bare metal stents (BMS, n = 58), or were deferred from revascularization (n = 165). Results: FFR was significantly higher in the deferred group (median and IQR); 0.85 (0.82 to 0.88) compared with the BMS (0.78; 0.76 to 0.82) and the DES (0.79; 0.77 to 0.82), P < 0.001. Pretreatment FFR was a significant determinant of long term event rates in the deferred patients (P = 0.002) but had no effect in patients treated by PCI. In the deferred group, there were fewer events (death, myocardial infarction, target vessel revascularization) compared with the BMS group; but no significant difference was observed between the DES and the deferred groups. Conclusions: In borderline FFR, long term outcome after PCI with BMS is inferior to conservative therapy or PCI with DES. While conservative management is preferable in these patients, PCI with DES may be considered in specific circumstances. © 2007 Wiley-Liss, Inc. [source] Modeling solvent evaporation during the manufacture of controlled drug-release coatings and the impact on release kinetics,,JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2009Chang-Soo Kim Abstract To improve functionality and performance, controlled drug-release coatings comprised of drug and polymer are integrated with traditional medical devices, e.g., drug eluting stents. Depending on manufacturing conditions, these coatings can exhibit complex microstructures. Previously, a thermodynamically consistent model was developed for microstructure evolution in these systems to establish relationships between process variables, microstructure, and the subsequent release kinetics. Calculations based on the model were, in general, consistent with experimental findings. However, because of assumptions regarding the evaporation of solvent during fabrication, the model was unable to capture variations through the coating thickness that are observed experimentally. Here, a straightforward method is introduced to incorporate solvent evaporation explicitly into the model. Calculations are used to probe the impact of solvent evaporation rate and drug loading on the microstructure that forms during manufacturing and subsequent drug release kinetics. The predicted structures and release kinetics are found to be consistent with experimental observations. Further, the calculations demonstrate that solvent evaporation rate can be as critical to device performance as the amount of drug within the coating. For example, changes of a factor of five in the amount of drug released were observed by modifying the rate of solvent evaporation during manufacturing. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Pharmaceutical aspects of drug eluting stentsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2008E. Deconinck Abstract This review focuses on the pharmaceutical aspects of the development of drug eluting stents. It discusses the different processes that can be used to obtain a controlled release of a drug from the stent as well as the coatings therefore applied. Results obtained for stents already available on the market or in a far stage of development are discussed. In a final part possible future research areas as well as expected new evolutions in the design of drug eluting stents are presented. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:5047,5060, 2008 [source] Plasminogen activator inhibitor-1 predicts coronary in-stent restenosis of drug-eluting stentsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2008K. M. KATSAROS Summary. Background:,We tested the hypothesis that plasma levels of plasminogen activator inhibitor-1 (PAI-1) are influenced by percutaneous coronary intervention (PCI) with the implantation of drug eluting stents (DES) and are able to predict the occurrence of in-stent restenosis (ISR). Methods and results:,PAI-1 active antigen plasma levels were determined in 75 patients before and 24 h after PCI with DES implantation. Patients with ISR after six to eight months (16%) showed significantly lower PAI-1 plasma levels before PCI (ISR, 11.7 ± 8.1 ng mL,1; non-ISR, 22.8 ± 18.8 ng mL,1; P <0.05). PAI-1 levels in the lowest tertile were associated with a 9.5-fold increased risk of ISR, independent of clinical risk factors, angiographic or procedural characteristics, compared to the highest tertile (P < 0.05). The induced change of PAI-1 active antigen 24 h after PCI was significantly higher in patients with ISR (ISR, +5.6 ± 8.0 ng mL,1; non-ISR, ,3.2 ± 12.1 ng mL,1; P < 0.05) with positive correlation to late lumen loss (r = 0.30; P < 0.05).Conclusions:,ISR after DES implantation is significantly related to plasma levels of PAI-1 active antigen before and after PCI. If confirmed by larger multicenter studies, the determination of PAI-1 plasma levels might be clinically helpful in the identification of patients at high risk of developing of ISR, even after DES implantation. [source] Liquid chromatography-tandem mass spectrometry method for determination of Sirolimus coated drug eluting nano porous carbon stentsBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010G. Rajender Abstract Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has proved to powerful research tool due to its sensitivity, high selectivity, and high throughput efficiency..Sirolimus was extracted from plasma by two-step extraction procedure using chloroform as extracting solvent. Signal intensity was high using ESI+ source provided for the quantitation of samples. Chromatographic separation was performed on phenomenax C-18 column (250 × 4.60,mm 5microns).Mobile phase contains acetonitrile, water (80; 20 v/v) + 0.1% acetic acid, flow rate 1,mL/min. The retention time of Sirolimus 8.4,min, the total run time10,min. Linearity correlation coefficients (r2) curve was 0.997183.calibraction range 10,1000,ng/mL. The UV detection of Sirolimus was at 278(277.78) nm. Sirolimus coated drug eluting stents, MRM (Multiple reaction monitoring) transition of Sirolimus m/z 936.83,208.84 was selected to obtain maximum sensitivity. LC/MS/MS results exhibited consistency in drug content on the stent surface. In-vitro release kinetic indicated the release of Sirolimus in 41 days from the date of implanted. Drug release was found at the first day, burst release was observed at 7th day of implantation. This study involved pharmacological coating of stents, based on the notion that sustained systemic local delivery of anti-proliferative agents. LC-MS/MS method has been successfully used in the pharmacokinetic analysis of Sirolimus coated drug eluting stents. Copyright © 2009 John Wiley & Sons, Ltd. [source] Scanning electron microscopic analysis of different drug eluting stents after failed implantation: From nearly undamaged to major damaged polymers,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2010Marcus Wiemer MD Abstract Background: Implantation of drug eluting stents (DES) in tortuous and/or calcified vessels is much more demanding compared with implantation of bare metal stents (BMS) due to their larger diameters. It is unknown whether drug eluting stent coatings get damaged while crossing these lesions. Methods: In 42 patients (34 male, 68.1 ± 10 years) with 45 calcified lesions (15.9 mm ± 7.9 mm), DES could not be implanted, even after predilatation. Diabetes was present in 19 patients (45 %). Sixty-one stents were used; 19 Cypher selectÔ, 18 Taxus LibertéÔ, 10 CoStarÔ, 5 Endeavor RXÔ, 4 Xience VÔ. 3 Janus CarbostentÔ, 1 Yukon Choice SÔ, and 1 AxxionÔ DES. The entire accessible surface area of these stents, in either the unexpanded and expanded state, were examined with an environmental scanning electron microscope (XL30 ESEM, Philips) to evaluate polymer or surface damage. Results: The polymers of Taxus Liberte, Cypher Select, Xience V, CoStar, and Janus DES were only slightly damaged (less than 3% of surface area), whereas the Endeavor RX Stents showed up to 20% damaged surface area. In DES without a polymer (Yukon and Axxion), it could be shown that most of the stent surface (up to 40%) were without any layer of drug. Conclusion: Placement of drug eluting stents in tortuous vessels and/or calcified lesions could cause major surface damage by scratching and scraping of the polymer or drug by the arterial wall, even before implantation. There were remarkable differences among the stents examined, only minor damage with the Cypher, Taxus Costar, Janus, and Xience V, whereas the Endeavor, the Yukon, and the Janus DES showed large areas of surface injury. © 2009 Wiley-Liss, Inc. [source] Five-year clinical outcomes after coronary stenting of chronic total occlusion using sirolimus-eluting stents: Insights from the rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital,(Research) Registry,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 7 2009Zhu Jun Shen MD Abstract Background: The use of drug eluting stents (DES) in patients with a successfully recanalized chronic total occlusion (CTO) has been associated with a significant decrease in the need for repeat revascularization, and a favorable short-term clinical outcome when compared with the use of bare metal stents (BMS). Our group, however, has previously reported similar rates of target lesion revascularisation (TLR) and major adverse cardiovascular events (MACE) at 3 years follow-up in patients with a successfully opened CTO who were treated with either a sirolimus eluting stent (SES) or a BMS. The objective of this report was to evaluate the outcomes of these patients at 5-years clinical follow-up. Methods and Results: A total of 140 (BMS 64, SES 76) patients with successfully opened CTOs were included. Seven patients died in the BMS group whilst nine patients died in the SES group (P = 0.90). Noncardiac death was the major component of all-cause mortality (11 noncardiac deaths vs. 5 cardiac). There were two and three myocardial infarctions (MI) in the BMS and SES group, respectively (P = 1.0). The composite of death and MI occurred in seven (10.9%) and eleven (14.5%) patients in the BMS and SES group, respectively (P = 0.53). Clinically driven TLR was performed in eight patients (12.5%) in the BMS group, and five (6.6%) in the SES group (P = 0.26). Non-TLR target vessel revascularization was performed in one patient in the BMS group, and four in the SES group (P = 0.37). The 5-year device-oriented cumulative MACE rate was 15.6% and 11.8% in the BMS and SES group, respectively (P = 0.56). Conclusion: In patients with a successfully treated CTO, clinical outcome after 5 years was similar between SES and BMS, however, clinically driven TLR was slightly higher in the BMS group. © 2009 Wiley-Liss, Inc. [source] Drug eluting stents for below the knee lesions in patients with critical limb ischemia,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2008Long-term follow-up Abstract Objectives: The purpose of this study was to assess the long-term limb preservation and/or healing of ulcers in patients with critical limb ischemia (CLI) and severe infrapopliteal atherosclerotic disease treated with drug eluting stents (DES). Background: Percutaneous revascularization has become an effective treatment for CLI in patients with infrapopliteal atherosclerotic disease. Recent reports using DES in patients with CLI have documented excellent short-term infrapopliteal vessel patency. Higher primary patency rates in infrapopliteal vessels treated with DES could translate into better long-term clinical outcomes and improved limb salvage rates. Methods: Twenty-four consecutive patients with CLI (defined as rest pain, nonhealing ulcers, or gangrene) because of severe infrapopliteal disease were treated with DES from August 2004 to June 2006. Results: Procedural success was achieved in 96% (27/28) of targeted lesions. There were no procedure-related deaths, acute vessel thrombosis events, or need for urgent surgical intervention. There was one case of distal embolization. Clinical follow up, ranging 8,34 months, is available for 100% of patients of which 83% (20/24) achieved limb preservation and healing. Angiographic and/or sonographic follow up, ranging 6,34 months, is available in 79% (19/24) of patients of which 95% (18/19) had patent target vessels. Conclusions: DES is a safe and effective long-term option for CLI due to severe infrapopliteal arterial disease. Long-term vascular patency led to a high rate of limb preservation and low amputation rate. A multicenter trial should further elucidate the role of DES in the treatment of CLI. © 2008 Wiley-Liss, Inc. [source] The effect of drug eluting stents on cardiovascular events in patients with intermediate lesions and borderline fractional flow reserve,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2007Shahar Lavi MD Abstract Objective: To assess the role of fractional flow reserve (FFR) in guiding therapy in the drug eluting stent (DES) era. Background: FFR is a useful index for evaluation of the physiological significance of angiographically indeterminate coronary artery lesions. However, its role in the DES era is unknown. Methods: Long term outcome of 281 patients with angiographically indeterminate coronary lesions and borderline FFR (0.75 , FFR < 0.9) was obtained. The outcome of patients who had a DES placed (n = 58), was compared with that of consecutive patients with borderline FFR that were treated by PCI with bare metal stents (BMS, n = 58), or were deferred from revascularization (n = 165). Results: FFR was significantly higher in the deferred group (median and IQR); 0.85 (0.82 to 0.88) compared with the BMS (0.78; 0.76 to 0.82) and the DES (0.79; 0.77 to 0.82), P < 0.001. Pretreatment FFR was a significant determinant of long term event rates in the deferred patients (P = 0.002) but had no effect in patients treated by PCI. In the deferred group, there were fewer events (death, myocardial infarction, target vessel revascularization) compared with the BMS group; but no significant difference was observed between the DES and the deferred groups. Conclusions: In borderline FFR, long term outcome after PCI with BMS is inferior to conservative therapy or PCI with DES. While conservative management is preferable in these patients, PCI with DES may be considered in specific circumstances. © 2007 Wiley-Liss, Inc. [source] Outcome in the real-world of coronary high-risk intervention with drug-eluting stents (ORCHID),A single-center study comparing CypherÔ sirolimus-eluting with TaxusÔ paclitaxel-eluting stentsCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2006S. Kumar MRCP Abstract Objective: We present real world experience from a single center registry comparing the 6-month outcome of percutaneous coronary intervention (PCI) in unselected high-risk individuals using either sirolimus-eluting (SES) or paclitaxel-eluting stents (PES). Methods/Results: We compared clinical outcome at 6 months follow-up in two cohorts of 156 consecutive patients(total n = 312) who underwent SES (June 2002,Februrary 2003) and PES(march 2003,July 2003) implantation. The primary endpoint was a composite of major adverse cardiac events (MACE). Baseline clinical characteristics were well matched. The 6-month target vessel revascularization (TVR) rates were 1.9% (SES) and 2.6% (PES) and MACE rates were similar in the two groups (SES 4.5% vs. PES 3.2%, P = NS). In the PES group, intervention for multivessel disease, bifurcation lesions and in small vessels was more common, and for in-stent restenosis less common, reflecting the impact of drug eluting stents on indications for PCI. The incidence of sub-acute stent thrombosis, related to inadequate antiplatelet therapy in 3 of the 6 cases, was 0.95% with no difference between the two groups. Conclusion: This study confirms the safety and efficacy of SES and PES in unselected high risk patients undergoing PCI. Clinical outcomes of both stents are equivalent at 6 months with low rates of MACE and TVR. These data provide important complementary information to forthcoming randomized studies. © 2006 Wiley-Liss., Inc. [source] Bifurcation stenting with drug eluting stents: Illustration of the crush techniqueCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2006Georgios Sianos MD Abstract A number of percutaneous stenting techniques have been proposed for optimal treatment of bifurcation lesions. However, to date the most favorable interventional approach still remains controversial, since bifurcation lesions are associated with high procedural complication and restenosis rates. In the era of drug-eluting stents, crush stenting technique simplified the procedure, concurrently allowing full lesion coverage. The purpose of the present report is to review three cases treated with crush stenting and to describe in detail the technique and its variations. © 2006 Wiley-Liss., Inc. [source] | ||||||||||||||||