Efficiency of medical versus endovascular treatment using drug-eluting stents in coronary heart disease patients with extensive lesion of the coronary bed

The goal of the study was to assess the long-term results of endovascular treatment using drug-eluting stents in coronary heart disease patients with extensive coronary artery lesion. The study covered 478 patients with diffuse coronary artery lesion, including 220 patients receiving endovascular treatment and 258 having medical treatment (a comparison group). The immediate angiographic results and long-term clinical efficiency of endovascular treatment using rapamycin-eluting stents were studied. The follow-up was 2 years. Repeat follow-ups were undertaken1and 2 years later. The immediate angiographic success rate of endovascular treatment for diffuse coronary artery lesions was 89.5%. The two-year follow-up showed the efficiency and expediency of endovascular treatment for extensive coronary artery lesions: the symptoms of angina pectoris occurred significantly less frequently symptoms, the exercise endurance was higher, and the need for antianginal medications was less in the invasively treated patients.     

冠状动脉弥漫性长病变治疗的研究进展

冠心病目前已经成为全球性关注的健康问题,为当今人类一大灾难性疾病。既往研究表明,冠状动脉弥漫性长病变占冠心病总患者约20%,冠状动脉弥漫性长病变患者其动脉粥样硬化的病变范围更加广泛,病变呈弥漫性,而且更多累及左主干,常常伴有血管直径小,血管成角、钙化、扭曲等特点,而且多发生于高龄、糖尿病患者中,以上特点又决定了冠状动脉弥漫性长病变成为冠心病治疗的又一难题。因此,有效的预防与治疗冠状动脉弥漫性长病变,已成为目前的关注重点与热点,本文概述了冠状动脉弥漫性长病变临床治疗中的常用方法以及各方法的疗效与优劣之势,多年临床实践经验表明PCI治疗仍占有主导位置,虽然目前冠状动脉弥漫性长病变的介入治疗应用药物洗脱支架的已经取得良好的临床效果,在很大程度降低了心血管事件发生率和再次血管重建率,但药物洗脱支架支架治疗冠状动脉弥漫性长病变的远期疗效仍在评估中。     

A single center experience with the newly designed R Stent in small coronary vessels

BACKGROUND: Over the past 10 years stents have been used more frequently for the treatment of de novo coronary artery stenosis. Initally these devices were used primarily in coronary arteries with diameters ranging from 3.0 to 4.0 mm. Traditionally, coronary arteries less than 3.0 mm in diameter were treated with only balloon angioplasty, due to the unavailablity of flexible, low profile, small diameter stents. In the past three years, many stents have been designed to be implanted in small coronary arteries. OBJECTIVE: The objective of this study was to evaluate the safety and feasiblity of the R Stent in patients with coronary lesions located in coronary arteries with a reference diameter 2.5-3.0 mm. METHODS AND RESULTS: Between November 1998 and September 1999, 32 patients with stable (37%) and unstable (63%) angina treated with the R Stent were included in this study. The treated lesions were in the right coronary artery (RCA) (n = 13), left cirumflex coronary artery (LCX) (n = 10), and left anterior descending coronary artery (LAD) (n = 9). Of these lesions thirteen were anatomically complex. Stent deployment was successful in 97% with one crossing failure in a patient with a vessel tortuosity of greater than 75 degrees of the circumflex artery. No post-procedual major adverse cardiac and cerebrovascular event (MACCE) occurred within 30 days of stent implantation. After the procedure, patients were scheduled for a two-week telephone follow-up and a one-month clinical evaluation. At 30 days, only one patient (3%) experienced the recurrence of angina Canadian cardiovascular society classification ((CCS) Class 2). All other patients were event and angina free. CONCLUSION: This first clinical experience in patients with small vessel disease shows that the use of the R stent is safe and feasible with low rates of acute stent thrombosis.     

冠状动脉内重叠支架置入术的临床研究进展

重叠支架置入术是临床上用来治疗冠状动脉弥漫性长病变的常用方法,以往曾采取重叠裸金属支架置入术,但其临床预后不佳,目前较为常用的重叠药物洗脱支架置入术被认为相对安全、有效,但仍存在许多潜在问题。本文介绍了适合使用重叠支架置入术进行治疗的冠状动脉病变的特点,回顾了重叠裸金属支架的临床应用情况,阐述了近年来药物洗脱支架的发展以及重叠药物洗脱支架置入术的优势,比较了四种负载不同药物的药物洗脱支架同种重叠置入后的临床疗效,观察了异种药物洗脱支架混合重叠置入后的临床特点和支架重叠段对临床预后的影响,分析了重叠支架置入术与几种其它治疗冠状动脉弥漫性长病变方法的应用区别,并对新一代药物支架的重叠应用进行了展望。     

Oxidative stress in myocardial ischaemia reperfusion injury: a renewed focus on a long-standing area of heart research

Advances in the treatment of coronary artery disease have seen a significant drop in mortality and morbidity particularly amongst patients with acute myocardial infarction (MI). In particular, percutaneous trans-luminal balloon angioplasty (PTCA) with stenting to re-open atherosclerotic coronary arteries has yielded marked improvement in clinical outcome for patients with acute MI. Furthermore, with the advent of drug-eluting stents occurrence rates for coronary artery restenosis, one common clinical problem associated with angioplasty and stent deployment, have declined markedly. However, coronary restenosis in diabetic patients remains an on-going problem. The success of drug-eluting stents has seen a renewed focus on myocardial ischaemia reperfusion (IR) injury as this represents one area of research where many questions remain unanswered. In particular, the relationship between myocardial IR injury and decreased myocardial micro-vasculature re-flow post PTCA (that ultimately leads to poor clinical outcome and myocardial damage/dysfunction) is one area of research with the potential to decrease current complication rates further in patients suffering myocardial IR injury sustained during MI. This review discusses the role for oxidative stress, oxidant source(s) and both gene regulation and stem-cell therapy as potential strategic targets in the ischaemic myocardium, with the ultimate aim of providing significant cardioprotection in the setting of acute MI.     

Impact of Coronary Artery Curvature on the Longitudinal Stent Foreshortening: Real-World Observations

Longitudinal stent foreshortening is a known phenomenon, however, the impact of coronary artery curvature on longitudinal stent foreshortening remains unclear. The aim of this study is to determine the impact of coronary artery curvature on the longitudinal stent foreshortening in the real-world scenarios. A total of 86 consecutive patients underwent coronary stent implantation were included in the present study. The degree of coronary artery curvature was defined as the length of the coronary artery curvature divided by the straight length. Longitudinal stent foreshortening was defined as the stent length after implantation divided by the stent length before implantation. The mean longitudinal foreshortening rate of coronary stents was about 94% in curved coronary arteries. Longitudinal stent foreshortening rate was positively correlated with the degree of coronary artery curvature (r = –0.86, P < 0.01). Coronary artery curvature is associated with significant longitudinal foreshortening of coronary stents, thus longitudinal foreshortening should be considered on deciding the stent length in curved coronary artery and a longer stent is usually needed in curved coronary artery.     

高龄（80-89 岁）非ST 段抬高心肌梗死早期 介入治疗的疗效观察

目的:研究调查高龄(80-89岁)非ST段抬高心肌梗死(non-ST-segment elevation myocardial infarction,NSTEMI)患者行早期经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)的有效性。方法:回顾分析2008年8月-2009年10月期间我院住院的66例80-89岁NSTEMI患者,冠状动脉造影检查后45例行PCI术,5例因为左主干病变或者严重的三支病变行冠脉搭桥(CABG)术,其余16例做保守治疗。发病到行介入治疗时间<72h。结果:45例行PCI术中42例成功,再血管化的成功率为63.6%,失败的3例PCI术病人中2例因导丝或球囊未能通过病变,1例为顽固性室速。共植入支架80枚,术后梗死相关动脉血流均达到TIMI2-3级。术后死亡2例(心源性休克、颅内出血各1例),死亡率为4.8%。住院期间出血并发症较高,有4(9.5%)例(穿刺部位血肿2例,消化道、颅内出血各1例)。住院期间无再发心肌梗死,偶发心绞痛2例。结论:穿刺尽管高龄(80-89岁)非ST段抬高心肌梗死冠脉早期介入主要出血事件较多,但可改善住院期间的预后。     

Treatment of recurrent coronary rupture by implantation of three coronary stent-grafts

The authors report a case of recurrent left anterior descending artery rupture during coronary interventions in a 70-year-old man. Coronary artery rupture was treated successfully by percutaneous coronary stent-graft implantation. Based on this experience, the authors advise against repeat angioplasty of a coronary artery which has ruptured during a prior intervention. Membrane-covered stents should be the first choice in the treatment of life-threatening coronary artery rupture.     

Treatment of coronary artery aneurysms by percutaneous sealing with bovine-pericardium-covered stents

The clinical significance of coronary artery aneurysms is briefly discussed. Until recently, surgical excision was the only treatment available. Single-case reports have documented aneurysm exclusion with vein-covered stents using 10 or 11 F. guiding catheters. This paper reports four patients with coronary artery aneurysms which were successfully excluded with the use of a novel pericardium-covered stent which is less invasive and shortens procedure time compared with the use of an autologous vein-grated stent and can be deployed using 8 F. or 9 F. guiding catheters. Short-term (five- to eight-month) clinical follow-up has been event-free in all patients, and in three patients six-month follow-up angiography has shown insignificant luminal loss.     

Clinical outcomes of long coronary stents: a single-center experience

BACKGROUND: Coronary artery stenting is particularly useful during percutaneous coronary intervention for long lesions previously associated with a low procedural success rate and a high complication rate of dissection and occlusion. Current treatment options include implantation of a single long stent, multiple contiguous stents, or 'spot' stenting. However, multiple stent implantation may result in sections of overlapping stent or gaps of unstented segments and is an independent predictor of restenosis. The early and intermediate clinical outcome of single and multiple long stent (>/= 30 mm) implantation is not established. METHODS AND RESULTS: The authors retrospectively identified 123 consecutive patients who had undergone stenting using one or more long coronary stents. Baseline clinical data, procedural outcomes and completed clinical follow-up to 52 weeks were obtained by case-note review. The majority (69%) required intervention for stable coronary disease. Seventy-seven per cent of lesions were either type B2 or C and only 2% were in saphenous vein grafts. The procedural success rate was 94%. A total of 15 major events occurred in 13 patients (11%). Ten acute events occurred and five events were during the follow-up period from 30 days to 52 weeks. Two patients died, one from uncontrolled bleeding secondary to the use of antithrombotic agents and one at four weeks due to sudden death. One patient had a postprocedural infarct. Two patients required in-hospital repeat revascularization for acute vessel closure and eight required revascularization during follow-up (three cases of occlusion/thrombosis and five cases of restenosis). CONCLUSIONS: The use of long coronary stents (>/= 30 mm) for the treatment of long diffuse native vessel disease, saphenous vein graft disease and long coronary dissections is associated with a reasonable procedural success rate and acceptable early and intermediate-term clinical outcomes.     

Would SYNTAX have been a positive trial if XIENCE V had been used instead of TAXUS?: A meta-analysis of a first-generation vs. a second-generation drug-eluting stent system

Treatment options for coronary revascularisation include percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). In the ‘synergy between PCI with TAXUS and cardiac surgery (SYNTAX)’ trial, PCI and CABG using state-of-the-art techniques (using paclitaxel-eluting stents and arterial grafts, respectively) were compared in the treatment of complex coronary artery disease. In Syntax, PCI was inferior to CABG at one year, entirely due to an increased repeat intervention rate. We hypothesised that the use of a superior drug-eluting stent system could reduce the need for repeat intervention. (Neth Heart J 2010;18:451-3.)     

Debate: PCI vs CABG: a moving target, but we are gaining

The treatment of patients with coronary artery disease continues to evolve; all three strategies – medical therapy, surgical revascularization, and percutaneous coronary intervention – have changed. Medical therapy with intense risk-factor modification and treatment with a statin, aspirin, and angiotensin-converting enzyme (ACE) inhibitors, should be used unless contraindicated. Surgical therapy has also changed with the introduction of minimally invasive, beating heart surgery. Percutaneous coronary intervention has perhaps changed the most radically with adjunctive therapy – glycoprotein IIb/IIIa inhibitors, thienopyridines, and reliance on stent implantation. The future, with new distal protection devices and drug-coated stents, should continue to see increased numbers of patients who can benefit from percutaneous intervention.     

Appropriate use of bioresorbable vascular scaffolds in percutaneous coronary interventions: a recommendation from experienced users: A position statement on the use of bioresorbable vascular scaffolds in the Netherlands

Percutaneous coronary interventions (PCI) have become a reliable revascularisation option to treat ischaemic coronary artery disease. Drug-eluting stents (DES) are widely used as first choice devices in many procedures due to their established good medium to long term outcomes. These permanent implants, however, do not have any residual function after vascular healing following the PCI. Beyond this initial healing period, metallic stents may induce new problems, resulting in an average rate of 2 % reinterventions per year. To eliminate this potential late limitation of permanent metallic DES, bioresorbable coronary stents or ‘vascular scaffolds’ (BVS) have been developed. In a parallel publication in this journal, an overview of the current clinical performance of these scaffolds is presented. As these scaffolds are currently CE marked and commercially available in many countries and as clinical evidence is still limited, recommendations for their general usage are needed to allow successful clinical introduction.     

c-kit-immunopositive vascular progenitor cells populate human coronary in-stent restenosis but not primary atherosclerotic lesions

Progress in the treatment of human in-stent restenosis (ISR) is hampered by an imprecise understanding of the nature of the cells that occlude vascular stents. Recent studies suggest that circulating vascular progenitor cells may mediate vascular repair and lesion formation. Moreover, functional endothelial progenitor cells appear to play a protective role in attenuating vascular lesion formation. Hence, we sought to answer two important questions: 1). Are primitive cells found in ISR lesions? 2). Is the abundance of cultured angiogenic cells (CACs) in patients with ISR different from that in patients with non-ISR lesions or normal controls? Human coronary atherectomy tissue from 13 ISR, 6 postangioplasty restenosis (RS), and 14 primary (PR) atherosclerotic lesions, as well as 15 postmortem coronary artery cross sections from young individuals without atherosclerosis, were studied. All 13 ISR and 4 of 6 RS tissue specimens contained cells that immunolabeled for the primitive cell marker c-kit and smooth muscle alpha-actin, whereas the intima and media of PR lesions and normal arteries were devoid of c-kit-immunopositive cells. The abundance of peripheral blood mononuclear cell-derived CACs was assessed in 10 patients with ISR, 6 patients with angiographically verified patent stents, and 6 individuals with no clinical evidence of coronary artery disease. CACs were less abundant in ISR patients than in non-ISR controls (13.9 +/- 3.1 vs. 22.3 +/- 6.7 cells/high-power field, P < 0.05), and both of these groups had fewer CACs than non-coronary artery disease patients (37.6 +/- 3.8, P < 0.05). These findings suggest a unique pathogenesis for ISR and RS lesions that involves c-kit-immunopositive smooth muscle cells. Moreover, the paucity of CACs in patients with ISR may contribute to the pathogenesis of ISR, perhaps because of attenuated reendothelialization.     

Mechanical and hydrodynamic effects of stent expansion in tapered coronary vessels

Percutaneous coronary intervention (PCI) has become the primary treatment for patients with coronary heart disease because of its minimally invasive nature and high efficiency. Anatomical studies have shown that most coronary vessels gradually shrink, and the vessels gradually become thinner from the proximal to the distal end. In this paper, the effects of different stent expansion methods on the mechanical and hemodynamic behaviors of coronary vessels and stents were studied. To perform a structural-mechanical analysis of stent implantation, the coronary vessels with branching vessels and the coronary vessels with large bending curvature are selected. The two characteristic structures are implanted in equal diameter expansion mode and conical expansion mode, and the stress and mechanical behaviors of the coronary vessels and stents are analyzed. The results of the structural-mechanical analysis showed that the mechanical behaviors and fatigue performance of the cobalt-chromium alloy stent were good, and the different expansion modes of the stent had little effect on the fatigue performance of the stent. However, the equal diameter expansion mode increased distal coronary artery stress and the risk of vascular injury. The computational fluid dynamics analysis results showed that different stent expansion methods had varied effects on coronary vessel hemodynamics and that the wall shear stress distribution of conical stent expansion is more uniform compared with equal diameter expansion. Additionally, the vortex phenomenon is not apparent, the blood flow velocity is slightly increased, the hydrodynamic environment is more reasonable, and the risk of coronary artery injury is reduced.

     

Drug-eluting stents: from bench to bed

The introduction of stents to clinical practice in 1987 was the major breakthrough in the field of percutaneous coronary intervention (PCI). The use of stenting has drastically improved the outcomes of traditional PCI. First stents were approved for bailout and treatment of dissections, reducing dramatically the need for emergent coronary artery bypass grafting (CABG) as a result of vessel closure during PCI. Later stents were proven to reduce the restenosis rate of PCI from 30%-40% with balloon angioplasty to 15%-20% with stents, primarily by eliminating elastic recoil and vascular remodeling as shown by intravascular ultrasound (IVUS) studies. These outcomes have led to a wide acceptance of stenting as the strategy of choice for more than 80% of all PCI procedures performed. The current review focuses on the following topics: (1) strategies in drug selection to reduce neointimal proliferation, (2) stent designs and polymer selection as a platform for drug-eluting stents, (3) review of major preclinical and clinical experimental work performed in the field, and (4) a discussion of the potential and limitations of the technology.     

Drug delivery patterns for different stenting techniques in coronary bifurcations: a comparative computational study

The treatment of coronary bifurcation lesions represents a challenge for the interventional cardiologists due to the lower rate of procedural success and the higher risk of restenosis. The advent of drug-eluting stents (DES) has dramatically reduced restenosis and consequently the request for re-intervention. The aim of the present work is to provide further insight about the effectiveness of DES by means of a computational study that combines virtual stent implantation, fluid dynamics and drug release for different stenting protocols currently used in the treatment of a coronary artery bifurcation. An explicit dynamic finite element model is developed in order to obtain realistic configurations of the implanted devices used to perform fluid dynamics analysis by means of a previously developed finite element method coupling the blood flow and the intramural plasma filtration in rigid arteries. To efficiently model the drug release, a multiscale strategy is adopted, ranging from lumped parameter model accounting for drug release to fully 3-D models for drug transport to the artery. Differences in drug delivery to the artery are evaluated with respect to local drug dosage. This model allowed to compare alternative stenting configurations (namely the Provisional Side Branch, the Culotte and the Inverted Culotte techniques), thus suggesting guidelines in the treatment of coronary bifurcation lesions and addressing clinical issues such as the effectiveness of drug delivery to lesions in the side branch, as well as the influence of incomplete strut apposition and overlapping stents.     

Verapamil Reverses Myocardial No-Reflow After Primary Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction

The present study evaluated the efficacy of intracoronary administration of verapamil to attenuate the no-reflow phenomenon following the primary percutaneous coronary intervention (PCI) in patients with the ST-segment elevation acute myocardial infarction (STEMI). A total of 201 patients with STEMI who underwent primary PCI within 12 h from the beginning of the heart attack were included. The no-reflow phenomenon was defined as substantial coronary anterograde flow of TIMI ≤2. Verapamil (100–200 μg) was injected into coronary artery immediately after no-reflow; the coronary arteriography was repeated later. Hundred and ninety-eight patients with STEMI successfully underwent primary PCI, and 246 stents were implanted with the average of 1.2 stents per patient. No-reflow occurred in 25 out of 198 patients (12.6 %). Twenty-one (84 %) patients developed the flow of TIMI ≥3 after intracoronary administration of verapamil, as revealed by repeated coronary angiography. Two patients developed transient hypotension which normalized without treatment within 3–5 min. Three patients showed sinus bradycardia, in one patient there was transient II sinoatrial block, and one patient developed type 1 atrioventricular block. All adverse effects were alleviated after intravenous injection of atropine (0.5–1 mg). In conclusion, the no-reflow phenomenon following primary PCI in patients with STEMI is significantly improved by intracoronary administration of verapamil which is useful to reduce cardiovascular events during operation.     

全数字化血管造影机应用探讨

目的探讨应用全数字化血管造影机检查的图像质量及X射线剂量。方法500人次冠状动脉造影检查,常规拍摄左前斜位加头位或足位,右前斜位加头位或足位,必要时加摄蜘蛛位。结果采取支架植入治疗左前降支狭窄92例,左回旋支狭窄28例及右冠状动脉狭窄45例,冠状动脉微细血管显示佳,管腔内血栓、血管内膜撕裂、支架等显示清晰。结论全数字化血管造影机采集的图像佳,X线剂量较低。     

Improved protocol for processing stented porcine coronary arteries for immunostaining

Percutaneous coronary intervention has resulted in a paradigm shift in the treatment of coronary artery disease and myocardial infarction. However, neither bare-metal stents nor polymer-coated drug-eluting stents represent ideal therapies at this time due to the undesired in-stent stenosis or delayed thrombosis. Hence there is pressing clinical need for greater understanding of the cellular mechanisms involved. It is hoped that this in turn will provide insight into designing and developing the next generation of stents. Although immunohistochemistry and immunofluorescence are appropriate tools in understanding the molecular histology, performing these techniques on stented blood vessels is technically challenging because of poor permeability of antibodies into the stented blood vessels which are embedded in methacrylate-based resins and inadequate image resolution due to autofluorescence. Hence there is a need to develop techniques which can facilitate immunohistochemistry/immunofluorescence procedures on stented blood vessel cross-sections. In this study we describe an improved protocol for processing stented porcine coronary arteries for immunostaining with smooth muscle cell, endothelial cell, monocyte and macrophage markers. We first identified the optimal conditions for resin embedding of stented artery and cross sectioned the vessels using high speed precision wafering diamond blade. The sections were then ground using two levels of water sandpaper on a Metaserve 2000 grinder to achieve the desired thickness. For immunostaining, we developed a novel deplasticization protocol which favors optimal antibody permeabilization. Our protocol not only provides feasibility of improved immunostaining of stented artery sections but also results in high quality images.