抗CD34抗体优化雷帕霉素洗脱支架疗效的实验研究

目的 评价抗CD34抗体对雷帕霉素洗脱支架早期再内皮化以及远期抗再狭窄的影响.方法 将裸金属支架(BMS)、雷帕霉素洗脱支架(SES)和抗CD34抗体与雷帕霉素洗脱联合支架(ASES)随机置入到22头中华小型猪的冠状动脉内(共置入15枚BMS、17枚SES和16枚ASES).10头中华小型猪在置入支架(共置入6枚BMS、7枚SES和7枚ASES)后2周,另外12头中华小型猪在置入支架(共置入9枚BMS、10枚SES和9枚ASES)后3个月,进行冠状动脉造影及冠状动脉内光学相干断层成像( OCT)检查,并在处死动物后对支架段冠状动脉进行病理组织学检查及扫描电镜观察.结果 (1)支架术后2周,冠状动脉造影、OCT图像及支架段冠状动脉的病理组织学的观察均未发现支架内血栓及小的附壁血栓.对OCT图像的分析显示,ASES新生内膜覆盖率显著高于SES[ (55.56±35.27)％比(41.82±23.28)％,P＜0.05];ASES平均内膜覆盖厚度不但显著高于SES[(89.0±5.0)μm比(32.0±4.9) μm,P＜0.01],而且显著高于BMS[( 89.0±5.0) μ,m比(44.0±7.2)μm,P＜0.01].病理组织学观察及扫描电镜观察显示,ASES和BMS新生内膜覆盖水平及质量均优于SES.(2)支架术后3个月,定量冠状动脉造影显示ASES晚期支架内管腔丢失显著低于BMS [(0.18±0.06)mm比(0.35±0.06)mm,P＜0.05];对OCT图像的分析显示,ASES和SES新生内膜增生百分比均显著低于BMS[ (34.75±2.64)％和(35.63±2.07)％比(48.28±3.25)％,均P＜0.01];组织病理学分析显示,ASES和SES面积再狭窄百分比均显著低于BMS组[(28.65±5.64)％和(29.33±6.07)％比(46.18±8.25)％,均P＜0.05].结论 将抗CD34抗体联合应用到雷帕霉素洗脱支架上能够显著抵消后者在支架术后2周对再内皮化的抑制作用,同时没有削弱雷帕霉素洗脱支架术后3个月的抗再狭窄效能.     

The genous™ endothelial progenitor cell capture stent accelerates stent re‐endothelialization but does not affect intimal hyperplasia in porcine coronary arteries

Objectives : To study the effect of endothelial progenitor cell (EPC) capture on the vascular response to coronary stenting. Background : The introduction of drug‐eluting stents has reduced the need for target lesion revascularization, but their effect on delayed healing, inflammation, and vascular dysfunction has emphasized the need to design strategies that improve current DES. One such strategy is to improve endothelialization by capturing CD34‐positive cells (EPC) by the stent surface. The first human clinical trial using coronary EPC capture stents showed stent safety but neointimal thickness (NIT) was not reduced compared to bare metal stents (BMS). To understand these responses we studied the coronary response to the EPC capture stent in swine. Methods and Results : The stent, coated with murine antihuman monoclonal CD34 antibodies, was assessed with QCA guided stent implantation in normal swine coronary arteries for early endothelialization at 2 and 5 days, and NIT at 28 and 90 days in comparison to control stents carrying a non‐specific murine antibody or to BMS. The main finding was that while the EPC capture stent significantly improved early endothelialization it did not reduce NIT at 28 and 90 days. Conclusions : The EPC capture stent improves early endothelialization in swine but this does not affect neointimal thickness as compared to control stents at 28 and 90 days. © 2011 Wiley Periodicals, Inc.     

光学相干断层成像在冠心病介入治疗中的应用价值

目的应用光学相干断层成像（OCT）技术评价冠状动脉内粥样硬化斑块、血管对置入支架后即刻和中远期的反应。方法20例冠心病患者,有22支血管在完成冠状动脉造影或介入治疗后进行OCT成像。同时获取23个支架OCT成像,在23个支架中有15个为支架术后4～35个月随访,其中7个为雷帕霉素药物洗脱支架,8个为金属裸支架,另外8个为支架置放后即刻成像。结果入选的20例患者均成功进行OCT检查,并获取22支血管和23个支架满意的图像。通过OCT成像清晰地显示8处纤维斑块、3处钙化斑块、9处富含脂质斑块、2处血栓形成、斑块破裂3处及血管壁上夹层、粥样硬化斑块微小裂口和夹层等。7个置入雷帕霉素药物洗脱支架后OCT随访,均未发现有明显再狭窄,支架表面有少量内膜覆盖,部分支架表面没有内膜覆盖,其中1个支架血管出现瘤样扩张、支架与血管壁分离、支架表面没有内膜覆盖,有1个支架没有充分扩张。8个金属裸支架后用OCT随访发现,所有置入金属裸支架后支架表面内膜增殖明显,其中有3个支架因为内膜过度增殖而出现再狭窄,并再次接受介入治疗。8个支架术后即刻OCT检查显示,与血管贴壁均良好、支架扩张充分有3个支架,4个支架充分扩张,但可见到斑块裂片通过支架网眼突入管腔,1个支架支撑杆分布不均,可见支架与血管壁分离,在8个支架中有2个为支架内套叠支架。结论OCT成像技术可清晰显示各种冠状动脉粥样斑块情况,并可用于评价冠状动脉介入治疗的效果。     

In-stent restenosis in bare metal stents versus sirolimus-eluting stents after primary coronary intervention for acute myocardial infarction and subsequent transcoronary transplantation of autologous stem cells

BACKGROUND: Following stenting for acute myocardial infarction, transcoronary transplantation of granulocyte-colony stimulating factor (G-CSF) mobilized autologous stem cells (ASC) has been shown to result in an increased in-stent restenosis rate of bare metal stents (BMS). HYPOTHESIS: This study sought to compare the extent of neointimal growth in BMS and sirolimus-eluting stents (SES) after primary implantation, and subsequent transcoronary transplantation of G-CSF mobilized stem cells. METHODS: Patients with stenting of the left anterior descending coronary artery for acute anterior myocardial infarction were randomly assigned to receive a BMS or SES. Intracoronary stem cell injection was performed after G-CSF application for at least 4 d and cell apheresis. The angiograms obtained after cell transplantation and after 6 mo were analyzed by quantitative coronary angiography. RESULTS: We performed primary stenting and stem cell transplantion in 16 patients who received a BMS (n = 8) or an SES (n = 8). In 2 patients with a BMS, late stent thrombosis occurred after 58 d and 177 d, respectively. In the remaining patients, control angiography after 6 mo revealed in-stent restenosis of >50% in no patients with SES but in 4 patients with BMS (67%). Late lumen loss and in-stent plaque volume were significantly higher in patients with BMS compared with patients with SES. CONCLUSIONS: Compared with BMS, SES impair in-stent intima hyperplasia after stenting for acute myocardial infarction and transcoronary transplantation of G-CSF mobilized ASC. Copyright (c) 2008 Wiley Periodicals, Inc.     

Feasibility of a Porcine Arteriovenous Shunt Model for Assessment of Acute Thrombogenicity in Bifurcation Stenting Technique By Optical Coherence Tomography

BackgroundDouble kissing (DK) crush stenting has been reported as a superior bifurcation stenting strategy compared to culotte stenting. However, the mechanism associated with the reduction of clinical events by DK crush stenting remains unclear. We therefore investigated the thrombogenicity of DK crush stenting and culotte stenting with both bare-metal stents (BMS) and drug-eluting stents (DES) and the feasibility of a novel porcine arteriovenous shunt model.MethodsHigh-resolution intracoronary imaging with optical coherence tomography (OCT) evaluated the bifurcation stenting models for thrombogenicity.ResultsAll porcine models retained continuous circulation without blood leakage. Thrombus was macroscopically demonstrated around the bifurcation in all settings. The volume of thrombus (mm³) with BMS using DK crush/culotte and DES using DK crush/culotte were 1.38/1.19 and 0.09/0.15, respectively. Culotte stenting had more thrombus in the proximal main branch, and DK crush stenting had more at the bifurcation. Unlike DK crush stenting, culotte stenting showed malapposition in the proximal main branch and bifurcation segments.ConclusionThe feasibility of a porcine arteriovenous shunt model to assess thrombogenicity by OCT in bifurcation stenting technique was confirmed. OCT detected less thrombogenicity in DES when used in the bifurcation model when compared to BMS.     

Late acute thrombosis after implantation of sirolimus‐eluting stent to treat in‐stent restenosis

Drug‐eluting stents (DES) have significantly reduced the incidence of in‐stent restenosis (ISR) compared to bare metal stents (BMS). However, recent randomized trials comparing DES with BMS reported few cases of late DES thrombosis. We report the case of late sirolimus‐eluting stent thrombosis occurring 22 months after its elective implantation in a restenotic BMS and soon after the interruption of combined anti‐platelet therapy with aspirin and Clopidogrel.     

Difference of neointimal growth patterns in bifurcation lesions among four kinds of drug‐eluting stents

Aim: Neointimal proliferation of bifurcation lesions after implantation of drug‐eluting stents (DES) has not been well evaluated. Thus, we compared neointimal proliferation of bifurcation lesions among four DES using optical coherence tomography (OCT). Methods: 8‐month follow‐up OCT was performed in 68 bifurcation lesions treated by 15 sirolimus‐eluting stents (SES) and 17 paclitaxel‐eluting stents (PES) as first‐generation DES, and by 17 zotarolimus‐eluting stents (ZES) and 19 everolimus‐eluting stents (EES) as second‐generation DES. Cross‐sectional images of the bifurcation lesion using OCT were analyzed every 450 µm. All images were divided into three areas: inner wall of the bifurcation (IB), outer wall of the bifurcation (OB), and ostium of the side branch (SB). We compared the incidence of uncovered struts (IUS) among three areas and the averaged neointimal thickness (NIH) between IB and OB in each stent and also compared these OCT parameters among all DES. Results: There were no significant differences of IUS between IB and OB in second‐generation DES, while in first‐generation DES, IUS of IB and OB showed significant differences. The IUS of SES in both areas was significantly higher than in the other DES (all P < 0.001). PES had a significantly higher IUS in SB than the others (all P < 0.001). NIH of OB was significantly higher than that of IB in PES, ZES, and EES, but in SES the NIH was similar in the two areas. Conclusions: OCT revealed different neointimal growth patterns among SES, PES, ZES, and EES in bifurcation lesions. © 2014 Wiley Periodicals, Inc.     

Coronary collateral function long after drug-eluting stent implantation.

OBJECTIVES: This study was designed to compare coronary collateral function in patients after bare-metal stent (BMS) or drug-eluting stent (DES) implantation. BACKGROUND: Drug-eluting stents have an inhibitory effect on the production of cytokines, chemotactic proteins, and growth factors, and may therefore negatively affect coronary collateral growth. METHODS: A total of 120 patients with long-term stable coronary artery disease (CAD) after stent implantation were included. Both the BMS group and the DES group comprised 60 patients matched for in-stent stenosis severity of the vessel undergoing collateral flow index (CFI) measurement at follow-up and for the duration of follow-up. The primary end point of the investigation was invasively determined coronary collateral function 6 months after stent implantation. Collateral function was assessed by simultaneous aortic, coronary wedge, and central venous pressure measurements (yielding CFI) and by intracoronary electrocardiogram during balloon occlusion. RESULTS: There were no differences between the groups regarding age, gender, body mass index, frequency of cardiovascular risk factors, use of cardiovascular drugs, severity of CAD, or site of coronary artery stenoses. Despite equal in-stent stenosis severity (46 +/- 34% and 45 +/- 36%) and equal follow-up duration (6.2 +/- 10 months and 6.5 +/- 5.4 months), CFI was diminished in the DES versus BMS group (0.154 +/- 0.097 vs. 0.224 +/- 0.142; p = 0.0049), and the rate of collaterals insufficient to prevent ischemia during occlusion (intracoronary electrocardiographic ST-segment elevation > or =0.1 mV) was higher with 50 of 60 patients in the DES group and 33 of 60 patients in the BMS group (p = 0.001). CONCLUSIONS: Collateral function long after coronary stenting is impaired with DES (sirolimus and paclitaxel) when compared with BMS. Considering the protective nature of collateral vessels, this could lead to more serious cardiac events in the presence of an abrupt coronary occlusion.     

Effectiveness of statin-eluting stent on early inflammatory response and neointimal thickness in a porcine coronary model.

BACKGROUND: Drug-eluting stent (DES) implantation is routine during coronary revascularization because DES significantly reduce rates of restenosis and target lesion revascularization compared with bare metal stent (BMS). However, available DES have limitations, such as late thrombosis because of delayed healing with poorer endothelialization and persistent local inflammation. Statins can inhibit cell proliferation, inflammation, and restore endothelial function. The present study evaluated the ability of stent-based cerivastatin delivery to reduce stent-induced inflammatory responses and adverse effects on endothelial function, and to inhibit neointimal hyperplasia in a porcine coronary model. METHODS AND RESULTS: Pigs were randomized into groups in which the coronary arteries (9 pigs, 18 coronaries in each group) had either a cerivastatin-eluting stent (CES) or a BMS. All animals survived without any adverse effects. Inflammatory cell infiltration evaluated using scanning electron microscopy on day 3 after stenting was significantly decreased in the treated vessels (inflammation score: 1.15+/-0.12 vs 2.43+/-0.34, p<0.0001). At day 28, endothelial function with intracoronary infusion of bradykinin was preserved in both the CES and BMS groups. Volumetric intravascular ultrasound images revealed decreased intimal volume in the CES group (28.3+/-5.4 vs 75.9+/-4.2 mm3, p<0.0001). Histomorphometric analysis showed reduced neointimal area (1.74+/-0.45 vs 3.83+/-0.51 mm2, p<0.0001) in the CES group despite similar injury scores (1.77+/-0.30 vs 1.77+/-0.22, p=0.97). CONCLUSION: In porcine coronary arteries CES significantly decreased neointimal hyperplasia with a decreased early inflammatory response and without endothelial dysfunction.     

In-stent neoatherosclerosis: a final common pathway of late stent failure

Percutaneous coronary intervention with stenting is the most widely performed procedure for the treatment of symptomatic coronary disease, and drug-eluting stents (DES) have minimized the limitations of bare-metal stents (BMS). Nevertheless, there remain serious concerns about late complications such as in-stent restenosis and late stent thrombosis. Although in-stent restenosis of BMS was considered as a stable condition with an early peak of intimal hyperplasia, followed by a regression period beyond 1 year, recent studies have reported that one-third of patients with in-stent restenosis of BMS presented with acute coronary syndrome that is not regarded as clinically benign. Furthermore, both clinical and histologic studies of DES have demonstrated evidence of continuous neointimal growth during long-term follow-up, which is designated as "late catch-up" phenomenon. Here, we present emerging evidence of de novo neoatherosclerosis based on histology, angioscopy, and intravascular images that provide a new insight for the mechanism of late stent failure. In-stent neoatherosclerosis is an important substrate for late stent failure for both BMS and DES, especially in the extended phase. In light of the rapid progression in DES, early detection of neoatherosclerosis may be beneficial to improving long-term outcome of patients with DES implants.     

Drug-eluting stent implantation could be associated with long-term coronary endothelial dysfunction

Drug-eluting stent (DES) implantation may be associated with endothelial dysfunction. However, changes in long-term endothelial function based on the type of DES remain largely unknown. We assessed coronary endothelial function after DES implantation compared to bare-metal stents (BMS) and determined the differences according to DES type. Patients who had single BMS or DES implantation in the left anterior descending artery and showed no restenosis in follow-up angiography at 6 to 9 months were assigned to the BMS group (5 patients) or DES group (9 sirolimus-eluting stents, SES, and 8 paclitaxel-eluting stents, PES). Endothelium-dependent vasomotion, after intracoronary infusion of acetylcholine, was determined by quantitative coronary angiography. Also, endothelium-independent vasomotion was assessed after nitrate infusion. In the distal and far distal segments, the SES (SES versus BMS, distal: -27.6 +/- 16.3% versus -0.6 +/- 1.6%; P = 0.01, far distal: -24.8 +/- 13.2% versus -0.9 +/- 1.3%; P = 0.02) and PES groups (PES versus BMS, distal: -25.4 +/- 17.1% versus -0.6 +/- 1.6%; P = 0.01, far distal: -26.6 +/- 15.9% versus -0.9 +/- 1.3%; P = 0.01) had similar patterns showing significant vasoconstriction compared with the BMS group. In addition, the DES group showed a significant reduction of diameter in distal (SES: P = 0.001, PES: P = 0.04) and far distal segments (SES: P = 0.002, PES: P = 0.001) compared with proximal and near proximal segments. However, the BMS group did not demonstrate significantly different vasomotion between proximal and distal segments. Vasodilatation by nitrate infusion was preserved in all subjects. SES or PES implantation could be associated with the similar pattern of endothelial dysfunction identified predominantly in the long distal portion of the treated vessel.     

Inflammation and delayed endothelization with overlapping drug-eluting stents in a porcine model of in-stent restenosis.

BACKGROUND: This study evaluated the inflammatory reaction at the site of overlapping drug-eluting stents (DES) in a porcine model of in-stent restenosis. METHODS AND RESULTS: Twenty bare metal stents (BMS) (group I; n=10), 20 sirolimus-eluting stents (SES) (group II: n=10), 20 paclitaxel-eluting stent (PES) (group III: n=10), and 10 PES and 10 SES (group IV: n=10) were overlapped in the left anterior descending coronary arteries of 40 pigs. Follow-up coronary angiography and histopathology were performed at 4 weeks after stenting. For the overlapped segments, the minimal luminal diameter at 4 weeks was smaller in group I than in the other groups (1.78+/-0.13 mm, 2.79+/-0.09 mm, 2.90+/-0.04 mm, 2.80+/-0.07 mm, respectively; p<0.001), and the neointimal area (5.51+/-0.58 mm2, 2.38+/-0.53 mm2, 2.07+/-0.37 mm2, 2.39+/-0.58 mm2, respectively; p<0.001) and area stenosis (68.74+/-4.02%, 27.79+/-4.73%, 23.66+/-3.24%, 27.63+/-4.07%, respectively; p<0.001) were higher in group I than in the other groups; however, the inflammatory score was higher in group III than in the other groups (1.80+/-0.42, 2.10+/-0.32, 2.90+/-0.31, 2.50+/-0.52, respectively; p<0.001) and the endothelization score was lower in group III than in the other groups (2.80+/-0.42, 2.30+/-0.67, 1.30+/-0.48, 2.10+/-0.74, respectively; p<0.001). CONCLUSION: Compared with BMS, DES inhibit neointimal hyperplasia, but inflammation and poor endothelization occur at the site of overlapping stents.     

Vascular Endothelial Growth Factor–Bound Stents: Application of In Situ Capture Technology of Circulating Endothelial Progenitor Cells in Porcine Coronary Model

Objectives

We evaluated the in vivo performance of a newly devised vascular endothelial growth factor (VEGF)‐bound stent in a porcine coronary model.

Background

An anti‐CD34 antibody‐bound stent, which captures endothelial progenitor cells (EPCs) to accelerate tissue formation, did not reduce intimal hyperplasia. By targeting the VEGF receptor, which is expressed on endothelial‐lineage cells, we developed VEGF‐bound stents that may enable selective capture of EPCs followed by rapid endothelialization.

Methods

Metallic stents were first coated with poly‐(ethylene‐co‐vinyl alcohol), and then chemically bound with either VEGF or anti‐CD34 antibody. These stents were placed in porcine coronary arteries for up to 14 days. Stent surface was evaluated by immunohistochemistry and by scanning electron microscope (SEM).

Results

After 2‐day stenting with VEGF‐bound stents, small populations of KDR (VEGF receptor‐2)‐positive cells adhered to the stent struts. After 7‐ and 14‐day stenting, struts were fully covered with newly regenerated tissue. SEM images showed that the uniform tissue formed on struts was morphologically similar to native endothelium and was continuously connected with adjacent native endothelium. On the other hand, for the anti‐CD34 antibody‐bound stents, stent struts were rapidly covered by newly generated tissue that consisted of multicellular aggregates.

Conclusions

Compared with anti‐CD34 antibody‐bound stents, VEGF‐bound stents provide highly selective capture of EPCs, followed by rapid formation of intact endothelium tissue at an early period of stenting. These results suggest that VEGF‐bound stents could represent a promising therapeutic option for cardiovascular stenting, although further long‐term follow‐up experiment with double‐blinded fashion is needed prior to clinical application. (J Interven Cardiol 2014;27:63–72)

     

Rationale and design of the Drug‐Eluting Stents vs Bare‐Metal Stents in Saphenous Vein Graft Angioplasty (DIVA) Trial

VA Cooperative Studies Program #571 (DIVA) was designed to evaluate the efficacy of drug‐eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure when compared with bare‐metal stents (BMS) in participants undergoing stenting of de novo SVG lesions. Participants undergoing clinically indicated stenting of de novo SVG lesions were randomized in a 1:1 ratio to DES or BMS. Randomization was stratified by presence/absence of diabetes mellitus and the number of target SVG lesions (1 vs ≥2) within each participating site. At sites that did not routinely administer 12‐months of dual antiplatelet therapy after SVG stenting participants without acute coronary syndromes received 1 month of open‐label clopidogrel, followed by 11 months of clopidogrel for those assigned to DES and 11 months of placebo for those assigned to BMS. The primary endpoint was the 12‐month incidence of target‐vessel failure (defined as the composite of cardiac death, target‐vessel myocardial infarction, or target‐vessel revascularization). Secondary endpoints included the incidence of other clinical endpoints and the incremental cost‐effectiveness of DES relative to BMS. Due to lower‐than‐anticipated target‐vessel failure rates, target enrollment was increased from 519 to 762. The study had randomized 599 participants when recruitment ended in December 2015. The DIVA trial will provide clarity on the appropriate stent type for de novo SVG lesions.     

Comparison of effects of drug-eluting stents versus bare metal stents on plasma C-reactive protein levels

After coronary stenting, inflammatory mechanisms play a crucial role in the pathogenesis of neointimal proliferation and in-stent restenosis. Drug-eluting stents (DESs) have been shown to decrease in-stent restenosis in different studies. We compared plasma C-reactive protein (CRP) levels after DES implantation with levels after bare metal stent (BMS) implantation. We performed percutaneous coronary intervention with a single stent in 67 patients (54 men; 59 +/- 9 years of age; n = 21 in the BMS group, n = 46 in the DES group) who had stable angina. Plasma CRP levels were determined before intervention and at 48 hours, 72 hours, and 2 weeks after coronary stenting. There was no difference in clinical and angiographic baseline characteristics except that the DES group had more patients with diabetes (34.8% vs 9.5%, p = 0.04), smaller reference vessels (2.95 +/- 0.53 vs 3.29 +/- 0.53 mm, p = 0.02), and smaller stent diameters (3.0 +/- 0.4 mm vs 3.4 +/- 0.5 mm, p <0.01). Plasma CRP levels at 48 hours (13.4 +/- 14.7 vs 5.9 +/- 4.9 mg/L, p <0.01) and 72 hours (16.7 +/- 19.8 vs 5.4 +/- 3.9 mg/L, p <0.01) after stent implantation were significantly higher in the BMS than in the DES group. In conclusion, DESs showed significantly lower plasma CRP levels after coronary stenting compared with BMSs. This may reflect the potent effects of DESs on acute inflammatory reactions induced by coronary intervention.     

Effects of oral prednisone after stenting in a rabbit model of established atherosclerosis.

OBJECTIVES: The aim of this study was to compare the effects of systemic prednisone in combination with a bare-metal stent (BMS) or a paclitaxel-eluting stent (Taxus, Boston Scientific Corp., Natick, Massachusetts) on neointimal inhibition and vessel healing in an atherosclerotic rabbit model. BACKGROUND: Inflammation plays a critical role in neointimal formation after coronary artery stenting. The efficacy of immunosuppressive doses of oral prednisone to inhibit in-stent neointimal proliferation was compared with BMS and with a commercially available paclitaxel-eluting stent (Taxus) in a rabbit model of established atherosclerosis. METHODS: Bilateral iliac artery injury in atherosclerotic New Zealand White rabbits fed an atherogenic diet was followed by stent implantation. Animals randomly received Taxus stents, BMS (Express, Boston Scientific Corp.) and placebo, or BMS and oral prednisone (2.1 mg/kg/day for the first 7 days, followed by 1.4 mg/kg/day for 14 days and 0.7 mg/kg/day for 21 days). Stented arterial segments were harvested at 42 days and processed for light microscopy, immunohistochemistry, and organoid culture. RESULTS: Compared with control subjects, prednisone-treated animals showed a 30% reduction in percent stenosis (p = 0.009), a 35% decrease in neointimal area (p < 0.003), and a 66% decrement in neointimal thickness (p < 0.001). Taxus stents also reduced all 3 parameters significantly (-34%, -39%, and -83%, respectively), but showed significantly more inflammatory cells and fibrin deposition and less endothelialization compared with the other 2 groups. Plaque burden was equal among groups, as shown by the identical stent and vessel area, and no remodeling was observed. CONCLUSIONS: Systemic prednisone treatment and Taxus stents reduce neointimal formation compared with BMS. The extent of neointimal reduction is similar between prednisone- and Taxus stent-treated animals; however, Taxus stents resulted in a significantly greater delay in healing. Targeting of inflammatory pathways after percutaneous coronary intervention may be an efficacious way to prevent restenosis without the long-term risk of late thrombosis.     

可降解聚乳酸涂层西罗莫司洗脱支架在小型猪冠状动脉模型中的实验研究

目的评价新型L605钴铬合金平台可降解聚乳酸共聚物载体西罗莫司药物洗脱支架（bioabsorbable polymeric sirolimus-eluting stent,BPSES）在小型猪冠状动脉抑制新生内膜增殖的有效性和安全性。方法金属裸支架（bare mental stent,BMS）18枚、单纯可降解聚乳酸共聚物涂层支架（bioabsorbable polymer-only stent,BPOS）18枚以及BPSES 18枚被分别随机置入18头小型猪的前降支（18枚）、回旋支（18枚）以及右冠状动脉（18枚）。置入28天和90天,复查冠状动脉造影评价管腔丢失。置入7天、28天以及90天处死部分动物行塑料包埋硬组织切片染色组织形态学分析。结果置入28天及90天,BPSES与BMS相比,显著降低管腔丢失（28天0.54±0.45 mm比1.11±0.45mm,P=0.048;90天0.42±0.34 mm比0.96±0.41 mm,P=0.024）。在损伤积分相似的情况下,置入28天时BPSES较BMS新生内膜面积明显减少（0.90±0.40 mm2比1.88±0.71 mm2,P=0.015）,而在90天时亦叮见此趋势,7天、28天和90天BPSES和BPOS炎症反应及内皮化程度与BMS相似。结论BPSES在置入小型猪冠状动脉28天后,可以安全有效地抑制新生内膜增殖,90天时亦可见此趋势。     

Clinical outcomes after heterogeneous overlap stenting with drug-eluting stents and bare-metal stents for de novo coronary artery narrowings

When it is difficult to deliver multiple drug-eluting stents (DES) or when size constraints limit DES implantation, bare-metal stents (BMS) may be implanted contiguous to DES. However, the clinical outcomes after overlapping DES and BMS implantation are not known. From September 2004 to June 2006, 4,872 consecutive patients who underwent percutaneous coronary intervention consented to be enrolled in a prospective registry. Of these patients, 44 (0.9%) with de novo lesions were treated with DES and BMS overlap stenting. All patients were followed to 12 months for the assessment of clinical outcomes. The average implanted stent diameter was 2.68 +/- 0.30 mm for DES and 2.35 +/- 0.38 mm for BMS. Overlapping BMS were implanted distal to DES in all but 1 case. One patient (2.3%) experienced acute stent thrombosis and died 2 days after the procedure. No other patient died or had a myocardial infarction during 12 months. The target vessel revascularization rate at 12 months, however, was 31.8%, mainly driven by diffuse in-stent restenosis in the BMS segments. In conclusion, the incidence of DES and BMS overlap stenting is rare in daily practice, but this procedure is associated with a high rate of target vessel revascularization.     

Bare-metal stent outcomes in an unselected patient population

BACKGROUND: Randomized trials have shown that drug-eluting stents (DES) substantially reduce in-stent restenosis compared with bare-metal stents (BMS). HYPOTHESIS: Revascularization event rates related to BMS restenosis may be higher in the trials setting than in real-world experience, calling into question the extent of benefit possible with widespread DES use in regular practice. METHODS: Between December 1998 and March 2003, 17,102 patients with BMS registered in the Goodroe Healthcare Solutions Data Warehouse met the inclusion criteria for this retrospective study of catheterization laboratory data. We examined the database for evidence of diagnostic angiography or percutaneous coronary intervention (PCI) readmission within 1 year after stenting. RESULTS: Repeat PCI was documented for 2070 patients, and 232 were referred for coronary artery bypass graft surgery (CABG)-in sum, 13.5% of the cohort. Stented region revascularization was observed in 8.4%: 1350 patients underwent subsequent PCI, and 84 of the patients referred for CABG had in-stent lesion recurrence. Only 1207 (7.1%) patients required stent-related PCI after 30 days, the time frame consistent with restenosis. CONCLUSIONS: In this "real-world" series, reintervention of a stented region after the first follow-up month was documented in fewer than 8% of patients in a large cohort that had received BMS. The rate of clinical events potentially related to BMS in-stent restenosis in this large, unselected patient population is substantially lower than that in the control arms of some DES trials. The incremental benefit of widespread conversion from BMS to DES may be smaller in some patient populations than is suggested by the results of those trials.     

Seven‐year safety and efficacy of the unrestricted use of drug‐eluting stents in saphenous vein bypass grafts

Objectives : The aim was to investigate the 7‐year clinical outcomes of patients treated with either drug‐eluting stents (DES) or bare‐metal stents (BMS) for saphenous vein graft disease (SVG). Background : Atherosclerotic disease in SVG has several peculiarities which make it difficult to extrapolate outcomes of the use of DES as compared to BMS, from outcomes observed in native coronary arteries. To date no long‐term safety and efficacy results for DES in SVG have been published. Methods : Between January, 2000 and December, 2005 a total of 250 consecutive patients with saphenous vein graft disease were sequentially treated with DES (either sirolimus‐ or paclitaxel‐eluting stents) or with BMS. Yearly follow‐up was performed. Results : At 87 months (7.25 years), a total of 101 patients died (58 [46%] in the BMS group and 43 [42%] in the DES group, P‐value= 0.4). There was no significant difference in the combined endpoint mortality or myocardial infarction. Cumulative target vessel revascularisation (TVR) was higher in the BMS group compared to the DES group (41% vs. 29%, respectively; adjusted hazard ratio [HR] 0.63, 95% confidence interval [CI]: 0.39–1.0). The cumulative incidence of major adverse cardiac events was 73% vs. 68% in the BMS and DES groups, respectively (adjusted HR 0.93, 95% CI: 0.67–1.3). Conclusions : In the present study, the unrestricted use of DES for SVG lesions appeared safe and effective up to 7.25 years‐ and the use of DES resulted in a clinically relevant lower rate of TVR. © 2011 Wiley Periodicals, Inc.