Initial clinical results with the Wiktor stent: a new balloon-expandable coronary stent

The Wiktor stent, a new coronary balloon-expandable tantalum stent, was implanted in 17 patients for other wise nonmanageable occlusion after balloon angioplasty (n = 11) and for recurrent restenosis (n = 6). Stents of 3.0 to 4.0 mm were implanted (right coronary artery: n = 10, left anterior descending artery: n = 4, left circumflex artery: n = 2, venous graft: n = 1). All patients were fully anticoagulated initially with heparin followed by coumadin for 3 months and were treated with acetylsalicylic acid indefinitely. Due to its good radiopacity, the device could be placed easily without complications. Early occlusion occurred in one patient after 8 h probably due to friable atheromatous material prolapsing between the meshes of the stent. Late occlusion occurred in another patient who was admitted in cardiogenic shock after pre-hospital reanimation and was stented after occlusive disection following balloon angioplasty of an occluded right coronary artery. In this patient with severe hypoxic brain damage, reocclusion and reinfarction to which the patient finally succumbed occurred following cessation of anticoagulation. Histology demonstrated occlusive thrombosis without evidence of a neointimal covering of the stent. Another thrombotic occlusion due to inadvertent omission of anticoagulation occurred in another patient two weeks after stenting. Control angiography after 6 months in 12 patients revealed restenosis in two patients (50% and 80%). The patient with 80% restenosis of the right coronary artery and pathologic results during stress testing underwent surgical revascularization. The other patient with a 50% restenosis of the right coronary artery was managed medically as he was asymptomatic and without evidence of ischemia during stress testing.(ABSTRACT TRUNCATED AT 250 WORDS)     

The current status of stent placement in small coronary arteries < 3.0 mm in diameter

Data accrued to date indicate that stent placement in small vessels (< 3.0 mm reference diameter) suffers from the same disadvantage as other non-stent interventional devices in that the restenosis rate is significantly higher than observed following intervention involving large vessels. Randomized trials comparing systematic bare metal stenting versus conventional balloon angioplasty in the setting of small coronary arteries, however, show that the former therapeutic modality is probably superior to the latter treatment in its acute and mid-term angiographic and clinical results. Balloon angioplasty, even if performed optimally with resultant stent-like luminal outcome, yields a restenosis rate that is at best equivalent to that observed with stent placement. Stent performance is influenced profoundly by stent design and configuration. Tubular and corrugated stents are better than coil or meshwire stent design. Stents with thin struts appear to yield a lower restenosis rate compared with thick-strut stents. Coating the surface of stents with gold, phosphorylcholine or heparin does not appear to confer any additional long-term benefit compared with bare stainless-steel stents. On the other hand, impregnation of stents with anti-proliferative drugs, with or without a carrier polymer, has produced a significantly lower risk of restenosis, without an increase in stent thrombosis rate, compared with uncoated metal stents in multiple randomized trials. However, whether the clinico-anatomic benefits of drug-eluting stents can be sustained for several years and whether there are any long-term deleterious effects from the antiproliferative drug or carrier polymer remains unclear at this stage.     

Abrupt (<1 day), acute (<1 week), and early (<1 month) vessel closure at the angioplasty site. Morphologic observations and causes of closure in 130 necropsy patients undergoing coronary angioplasty

While abundant clinical and angiographic data are available regarding features of acute or abrupt closure at the site of balloon angioplasty, little morphologic information is available. This study discusses morphologic-histologic causes for acute closure after angioplasty in 130 necropsy patients. Intimal-medial flaps, elastic recoil, and primary thrombosis were the three leading morphologic causes for closure. Data were subdivided into time categories: abrupt (<1 day), acute (<1 week), and early (<1 month). Intimal-medial flaps remained the most common cause for angioplasty closure despite time from angioplasty to documented occlusion. Morphologic recognition of types and frequencies of angioplasty closure are discussed, and specific mechanical, phar-macologic, or combined treatments are reviewed.     

Inter-Series differences in the restenosis rate of palmaz-schatz coronary stent placement: Differences in demographics and post-procedure lumen diameter

Restenosis rates following Palmaz-Schatz stenting vary between 13 and 36%. To determine whether the nearly three-fold interseries difference in restenosis rates reflects systematic factors (demographic and procedural variables such as post-treatment lumen diameter) rather than random variation, we pooled 486 lesions treated with the Palmaz-Schatz coronary stent in the U.S. Multicenter Registry (n = 259) with the single-center Beth Israel Hospital experience (n = 227) and analyzed the combined series using a continuous geometric model of restenosis. A greater proportion of lesions (66 vs. 50%; P < 0.001) in the Multicenter cohort represented restenosis after a prior intervention. The Multicenter experience also showed a smaller minimum lumen diameter following stent placement (2.61 vs. 3.43 mm; P < 0.001), higher post-stent percent stenosis (16 vs. –2%; P < 0.001), and less acute gain (1.79 vs. 2.67 mm; P < 0.001) than lesions treated in the Beth Israel cohort. At 6-month follow-up, the angiographic restenosis rate (≥ 50% diameter stenosis) was significantly higher in the Multicenter group (35 vs. 27%; P = 0.05), despite the development of less absolute late loss (0.96 vs. 1.32 mm; P < 0.001). Multivariable modeling, however, showed that the only independent predictors of restenosis were a post-procedure lumen diameter < 2.80 mm (odds ratio = 1.57; P = 0.04), diabetes mellitus (odds ratio = 3.55; P < 0.001), and prior restenosis (odds ratio = 1.84; P = 0.008). Since center (Beth Israel vs. Multicenter) was eliminated from the multivariable model after inclusion of these variables, the observed higher restenosis rate in the Multicenter series of Palmaz-Schatz coronary stents can thus be explained in part by differences in demographics (more previously treated lesions) and procedural details (a smaller posttreatment lumen diameter). Since post-procedure lumen diameter is a strong predictor of freedom from restenosis in the pooled experience, the probability of restenosis within a Palmaz-Schatz stent can be decreased by obtaining a large post-procedure lumen diameter.     

雷帕霉素药物洗脱支架治疗冠状动脉小血管病变的临床即刻效果

目的评价国产雷帕霉素药物洗脱支架(Firebird支架)治疗冠状动脉小血管病变(直径≤2.5mm)的临床即刻效果。方法采用前瞻性、非随机对比研究方法,根据入选和剔除标准,连续入选2004年6月~2007年2月我院行冠状动脉造影(CAG)确诊,首次接受经皮冠状动脉介入治疗(PCI)的靶血管为小血管病变且达到完全血运重建的160例患者,根据所置入的支架分为Firebird组(82例)和Cypher组(78例);支架置入后以相同的方法进行CAG,观察对比反映临床即刻效果的相关参数。结果术中全部Cypher及Firebird支架均顺利到达并释放于靶病变部位。两组支架的PCI手术成功率均为100%。Firebird组病变部位狭窄程度由术前的(78.7±15.6)%减至(7.20±10.69)%,P=0.0005;而Cypher组病变部位狭窄程度由术前的(79.8±15.8)%减至(7.10±10.61)%,P=0.0004。在急性管腔直径获得方面,Firebird组(1.76±0.52)mm与Cypher组(1.77±0.53)mm之间无显著差异(P=0.46)。结论Cypher和Firebird支架治疗冠状动脉小血管病变安全可行,临床即刻效果好。     

Can coronary flow parameters after stent placement predict restenosis

Intracoronary stent was used to treat a dissection resulting from balloon angioplasty. Coronary flow parameters measured with Doppler Flowire pre- and post-stenting suggested abnormal coronary flow even after stenting. The patient returned 4 months later with an instent restenosis. This case suggests the intriguing possibility of coronary flow parameters obtained immediately after new device angioplasty in predicting restenosis. © 1995 Wiley-Liss, Inc.     

The elective use of the seven-cell NIR stent in coronary arteries < 2.75 mm in diameter: clinical and angiographic results at 6-month follow-up.

The outcome of interventional procedures has been improved by the use of coronary stents in vessels > 3.0 mm in diameter. We report a single-center prospective study of elective coronary stenting in 39 consecutive patients with de novo lesions and reference diameters < 2.75 mm. Seven-cell NIR stents were deployed with standard antiplatelet therapy, but without routine use of IIb/IIIa inhibitors or intravascular ultrasound. There was one case of acute stent thrombosis, but no cases of subacute thrombosis. The binary restenosis rate was 27.8% (10/36 lesions) and the target lesion revascularization rate was 19.4%. Symptoms improved markedly as judged by Canadian Cardiovascular Society and questionnaire scores and the use of antianginal therapy. This pilot study suggests that the elective use of coronary stents in vessels < 2.75 mm in diameter is safe with acceptable long-term results. A randomized trial comparing outcomes after stents and balloon angioplasty in small vessels is required.     

Effect of stents in reducing restenosis in small coronary arteries: A meta‐analysis

The ability of stents to reduce restenosis was established in larger coronary arteries. Clinical trials of stenting in smaller vessels have yielded conflicting results due in part to their sample sizes. The aim of this meta‐analysis was to increase the statistical power by pooling data from these clinical trials. Trials were identified from Medline search, review of recent cardiology meetings' abstracts, and manual review of bibliographies. Studies were included if they were prospective randomized controlled trials. Endpoints examined included a dichotomized definition of angiographic restenosis, target lesion revascularization (TLR), target vessel revascularization (TVR), or any repeat revascularization. Pooling of data was performed by calculating a Mantel‐Haenszel odds ratio (OR). The analysis included 2,598 patients enrolled in eight clinical trials. Stenting significantly reduced restenosis (OR = 0.62; 95% CI = 0.61–0.63). Concordantly, stenting reduced TLR (OR = 0.49), TVR (OR = 0.90), and any revascularization (OR = 0.48). This meta‐analysis supports the hypothesis that stenting reduces restenosis in small coronary arteries as well as in larger coronary arteries. The apparent discordant result of individual clinical trials was due in part to underpowering related to small sample sizes. Catheter Cardiovasc Interv 2004;62:425–429. © 2004 Wiley‐Liss, Inc.     

犬冠状动脉内血浆包膜支架的生物相容性研究

目的 :评价血浆包膜支架在犬冠状动脉内的生物相容性。方法 :分别在犬左冠状动脉的回旋支和前降支随机植入 1个血浆包膜支架和 1个裸支架 ,术后 3d和 15 d（n=4）扫描电镜观察血小板粘附和血管内膜的内皮化情况 ,术后 1月 （n=5 ）进行冠脉造影和光镜检查。结果 :支架植入术后 3d,血浆包膜支架组和裸支架组的血小板粘附数无显著差异 （P>0 .0 5 ） ;术后 15 d,两组血管内膜均完全被新生内皮细胞覆盖 ;术后 1月 ,两组血管的损伤程度相同 ,冠脉造影和病理学检查均显示 ,两组的狭窄程度无区别 ,血管壁无大量的异物巨细胞聚积。结论 :血浆包膜支架具有良好的生物相容性     

“T”-shaped stent placement: A technique for the treatment of dissected bifurcation lesions

Despite operator experience and improved catheter technology, acute vessel closure is inherently associated with percutaneous transluminal coronary angioplasty (PTCA) of complex lesions. This case study describes a patient who developed an occlusive dissection post PTCA at the bifurcation of the left anterior descending artery (LAD) and its diagonal branch. The “T”-shaped wiktor stent placement immediately re-establishes full flow, obviating the necessity for emergent surgery. © 1996 Wiley-Liss, Inc.     

Influence of lesion length on restenosis after coronary stent placement

The length of a coronary lesion is a significant predictor of restenosis after balloon angioplasty. The influence of lesion length has not comprehensively been assessed after coronary stent placement. This study includes 2,736 consecutive patients with coronary stent placement. Only patients with recent or chronic occlusions before the intervention were excluded. Patients were divided in 2 groups: 573 patients with long lesions (≥15 mm) and 2,163 patients with short lesions (<15 mm). There were no significant differences between the groups with respect to the procedural success rate and incidence of subacute thrombosis. One-year event-free survival was lower in patients with long lesions (73.3% vs 80.0%, p = 0.001). Six-month angiography was performed in 82.5% of the eligible patients. The incidence of binary restenosis (≥50% diameter stenosis) was higher in patients with long lesions (36.9% vs 27.9%, p <0.001). Similarly, patients with long lesions presented more late lumen loss than those with short lesions (1.29 ± 0.89 vs 1.07 ± 0.77 mm, p <0.001). Multivariate models for both binary restenosis and late lumen loss demonstrated that lesion length was an independent risk factor for restenosis. The risk was further increased by multiple stent placement and overlapping stents that were also independent risk factors of restenosis. Stented segment length did not show any independent effect. Therefore, long lesions represent an independent risk factor for restenosis after coronary stent placement. The results of this study suggest that a possible way to reduce the risk is to cover the lesion with a minimal number of nonoverlapping stents.     

Cutting balloon coronary angioplasty—initial clinical experience

The success of percutaneous transluminal coronary angioplasty is limited by acute occlusion and late restenosis. In 25 patients (20 men, 5 women, age range 36–81 years) coronary angioplasty was performed using a new cutting balloon into which 3–4 longitudinally orientated blades are incorporated so as to reduce the rate of severe dissections. In 12 patients stenoses were reduced from 83.9 ± 7.8% to 28.4 ± 10.7% (mean ± SD) by the cutting balloon alone, using predilatation with a small conventional balloon in two cases. Thirteen other patients were additionally dilated with a conventional balloon because of a residual stenosis > 50% after cutting balloon angioplasty. Here the stenoses could be reduced from 78.1 ± 8.7% to 29.1 ± 11.3%. Six months follow-up angiography in 14 patients showed > 50% restenosis in two of seven patients dilated with a conventional balloon in addition to the cutting balloon, and in one of seven patients dilated with the cutting balloon alone but predilated with a small conventional balloon. These results show that coronary angioplasty by the new cutting balloon results in a stenosis reduction comparable with conventional balloons at a low complication rate. Available 6 months follow-up data show three restenoses in patients either pre- or postulated by a conventional balloon and none in stand-alone cutting balloon cases.     

Multiple stent implantation in single coronary arteries: Acute results and six-month angiographic follow-up

A total of 147 stents were implanted (in overlapping manner in 76% of vessels) in a single coronary artery in 59 patients (60 vessels, 97 lesions, 2.45 stents/vessel) over a period of 18 mo using high pressure stent deployment without ultrasound guidance. The indications for stenting were suboptimal percutaneous transluminal coronary angioplasty (PTCA) result (45%), primary prevention of restenosis (44%), acute closure (10%), and restenosis after plain balloon angioplasty (1%). One patient required emergency coronary artery bypass grafting (CABG) (extensive dissection), and one required early intervention with plain balloon angioplasty and intracoronary urokinase for stent thrombosis. There were no deaths. Thirteen patients had recurrence of angina within 6 mo and angiograms were performed in all. These showed intrastent restenosis in nine (all had successful repeat plain balloon angioplasty), development of new disease in other vessels along with restenosis close to the stent in the target vessel in one (underwent elective CABG) and normal angiograms with widely patent stents in three. Forty-five patients (77%) remained free of recurrent angina and 25 of these had follow-up angiograms (56%) at a mean of 172 days, two showing restenosis. Thus, the restenosis rate per patient in the symptomatic group (angiographic follow-up in 100%) was 77% and in the asymptomatic group (angiographic follow-up in 56%) was 8%. The restenosis rate in the subgroup with bailout stenting (n = 6) was 20% (angiographic follow-up in 83%). The overall restenosis rate per patient was 32% (overall angiographic follow-up in 66%). During the 6-mo follow-up period, one patient underwent elective CABG (1.7%), one sustained a non-Q myocardial infarction (1.7%), nine had repeat PTCA to the target vessel (15.5%), and there were no deaths. The event-free survival rate was 77%. Multiple stent implantation aided by high pressure stent deployment without ultrasound guidance and with adjunctive optimal antiplatelet therapy without oral anticoagulation seems to be a useful and effective revascularisation strategy to deal with long lesions and acute dissections with a high procedural success rate. The restenosis rate is acceptable and is not appreciably high as reported in previous studies from the “warfarin era.” Cathet. Cardiovasc. Diagn. 42:158–165, 1997. © 1997 Wiley-Liss, Inc.     

Long-term intracoronary stent placement: Arteriographic and histologic results after 7 years in a dog model

Prosthetic intracoronary stenting has become an important adjunct to balloon angioplasty in the percutaneous treatment of coronary artery disease. However, there are few reports of the long-term histologic consequences of stenting in the world literature. We report the arteriographic, histologic, and ultrastructural examination of a flexible tantalum wire coil stent implanted in the coronary artery of a dog for 7 years. The vessel was arteriographically patent without evidence of either stenosis or ectasia. The stent had been incorporated into the arterial wall, and was covered with a neointima of approximately 100 μm maximum thickness. There was necrosis of the tunica media adjacent to the stent but the inflammatory response was restricted to occasional macrophages in the neointima of the immediate vicinity of the stent wire. The endothelial cell layer was normal in its morphologic appearance. In summary, the flexible tantalum wire coil stent was well tolerated by the host blood vessel and demonstrated acceptable biocompatibility for the 7-year duration of its implantation in the normal dog coronary artery. © 1996 Wiley-Liss, Inc.     

Clinical and angiographic outcome after angiography-guided stent placement in small coronary vessels

BACKGROUND: Although it is widely accepted that stenting confers favorable angiographic and clinical results in coronary arteries >/=3.0 mm in diameter, the outcome of stent placement in smaller vessels remains largely unclear. METHODS AND RESULTS: We sought to specifically determine the early and long-term clinical outcomes in a large series of 197 consecutive patients who underwent stent placement in 207 vessels <3.0 mm in diameter. Procedural success, accomplished in 97.3%, was accompanied by a significant reduction in lesion severity from 85% +/- 9% before to 3% +/- 7% diameter stenosis after the procedure (P =.0001) and a 0.5% incidence of subacute stent thrombosis. At 1 and 2 years of follow-up, survival rate without major target lesion-driven events was observed in 77.3% and 73.9% of patients, respectively. Repeat revascularization procedures accounted for most of these events; cardiac deaths (including those related to subacute stent thrombosis) and late (>30 days) myocardial infarctions were infrequent (2.4% and 1.0%, respectively). The 6-month angiographic binary instent restenosis rate was 30.1%. On multivariate analysis, diabetes mellitus (P =. 0275), small baseline reference vessel size (P =.0300), and stent size 相似文献   

Balloon-based radiation therapy for treatment of in-stent restenosis in human coronary arteries: results from the BRITE I study.

Catheter-based intracoronary radiation therapy demonstrated reduction of the recurrence rate of in-stent restenosis by 35%-50% when compared to conventional therapy. The objectives of this study were to determine the safety and feasibility of a new balloon-shaped source design and a higher applied dose to reduce the restenosis rates. Thirty-two patients with in-stent restenosis who met study eligibility criteria were successfully treated with standard PCI techniques. Following a successful intervention, a P-32 beta-balloon source was positioned to cover the angioplasty site and a dose of a 20 Gy at 1 mm from the surface of the source was administered. The primary endpoint was a composite of major adverse cardiac events (any death, MI, emergent CABG, or repeat target vessel revascularization) during 6 months of follow-up. At 6 months, only one patient underwent repeat PTCA to the target vessel (3%). There were no instances of death, emergency surgery, late thrombosis, total occlusions, or MI. Binary restenosis measured by QCA at the stented segment was 0% and for the whole analysis vessel was 7.5%. Beta-radiation delivered with a balloon P-32 source design for patients with in-stent restenosis results in lower than expected rate of angiographic and clinical restenosis and the absence of late complications.     

The effect of intracoronary fibroblast growth factor-2 on restenosis after primary angioplasty or stent placement in a pig model of atherosclerosis

BACKGROUND: Therapeutic angiogenesis, if combined with primary percutaneous transluminal coronary angioplasty or stent placement, could improve the outcome of patients suffering from multifocal coronary disease. HYPOTHESIS: Because of the concern that angiogenic growth factors might promote restenosis, we studied the effect of a single intracoronary administration of recombinant fibroblast growth factor (rFGF)-2 on restenosis after balloon angioplasty and stent placement in a pig model of coronary atherosclerosis. METHODS: In 24 Yucatan minipigs, coronary lesions were induced by arterial injury and 3 months of atherogenic diet. After 3 months, repeat catheterization was performed with balloon dilation or stent placement at the injured sites, with a follow-up of 6 weeks. Results were monitored using quantitative angiography, intravascular ultrasound (IVUS), and histomorphometry. RESULTS: Intracoronary rFGF-2 2 microg/kg did not affect neointima formation or remodeling in this model. A small but significant aggravation of late lumen loss was observed in the reference segments of the rFGF-2-treated group. Angiographic and echographic late lumen loss, intimal hyperplasia, and arterial remodeling, as well as histologic neointima were all similar in the rFGF-2- and the vehicle-treated group. Confirming earlier studies from our group and those of others, stented arteries compared with balloon-dilated arteries had increased angiographic late lumen loss, a trend toward increased intimal hyperplasia and decreased remodeling. CONCLUSION: We conclude that rFGF-2 does not aggravate restenosis after balloon dilation or stenting in this pig model of coronary atherosclerosis. Future combinations of angioplasty and therapeutic angiogenesis in a single session should be pursued as a feasible and safe strategy.     

Comparison of the self-expanding Radius stent and the balloon-expandable Multilink stent for elective treatment of coronary stenoses: a serial analysis by intravascular ultrasound.

We compared the outcome of the self-expanding Radius stent and the balloon-expandable Multilink stent serially by angiography and intravascular ultrasound. Successful stent deployment was achieved in 66 lesions of 56 stable angina patients (34 lesions with Radius stents and 32 lesions with Multilink stents). At follow-up, there were no significant differences in minimal lumen diameter or percent diameter stenosis between the groups, nor in restenosis rates, although the Radius stent group rate was slightly lower (23.5% vs. 31.3%). In the Radius stent group, stent cross-sectional area (CSA) increased gradually after implantation until the 6-month follow-up (8.37 +/- 1.83 to 10.16 +/- 2.59 mm(2); n = 15), giving a larger CSA (P = 0.03) than the Multilink stent group, which decreased (9.00 +/- 2.05 to 8.27 +/- 2.15 mm(2); n = 17). The lumen CSA was also slightly larger (6.82 +/- 3.06 vs. 5.84 +/- 1.85 mm(2); P = 0.29) in the Radius stent group. These findings indicated that the Radius stent enlarged progressively after implantation, which might be useful for prevention of restenosis.