国产生物可降解聚合物支架与进口永久聚合物支架在冠状动脉血运重建中的对比

背景：雷帕霉素洗脱支架是冠状动脉支架置入后再狭窄的有效防治措施,是国产和进口支架材料会有什么区别吗？ 目的：比较新型国产EXCEL生物可降解聚合物雷帕霉素洗脱支架与进口Cypher永久聚合物雷帕霉素洗脱支架的疗效和安全性。 方法：回顾性分析259例冠状动脉心病患者临床资料,根据置入支架的不同分为两组进行比较观察：EXCEL支架组(n=130)：置入新型国产生物可降解聚合物雷帕霉素洗脱支架;Cypher支架组(n=129)：置入进口永久聚合物雷帕霉素洗脱支架。 结果与结论：256例患者完成随访,失访者3例,其中EXCEL支架组1例, Cypher支架组2例,失访率为1%。两组患者各有2例发生急性和亚急性血栓,Cypher支架组患者有3例发生晚期血栓。两组之间比较差异无显著性意义(P > 0.05)。随访期间未发生支架内再狭窄。置入后18个月无主要不良心脏事件生存率为98.8%,置入后亚急性血栓发生率1.56%。提示,EXCEL生物可降解聚合物雷帕霉素洗脱支架与Cypher永久聚合物雷帕霉素洗脱支架在冠状动脉血运重建方面的近期及远期各项指标差异无显著性意义,两者均是安全可靠的。     

雷帕霉素洗脱支架置入抑制猪TNF-α表达

 目的: 研究雷帕霉素洗脱支架置入对血管局部炎症因子TNF-α表达的影响J及雷帕霉素洗脱支架预防支架内再狭窄的作用机制。方法：小型家猪14头冠脉造影后随机分为雷帕霉素洗脱支架组和金属裸支架组并分别置入支架。ELISA法检测术前、支架置入术后7天及28天猪外周血细胞因子TNF-α的水平;RT-PCR方法检测支架置入术后28天血管局部组织TNF-α的基因表达情况。结果: 雷帕霉素洗脱支架组支架置入术前、术后7天和术后28天测定血清TNF-α水平没有统计学差异;而裸支架组TNF-α水平呈逐步上升趋势,与术前相比,术后28天TNF-α水平明显增高,具有统计学意义。两组间术前及支架置入术后7天TNF-α水平没有统计学差异,而支架置入术后28天,两组间比较雷帕霉素洗脱支架组血清中TNF-α水平明显降低。结论：雷帕霉素洗脱支架可以抑制血管局部组织TNF-α的表达从而抑制血管局部的炎症反应。 关键词： TNF-α 雷帕霉素洗脱支架 支架内再狭窄     

Underuse of coronary revascularization procedures in patients considered appropriate candidates for revascularization

BACKGROUND: Ratings by an expert panel of the appropriateness of treatments may offer better guidance for clinical practice than the variable decisions of individual clinicians, yet there have been no prospective studies of clinical outcomes. We compared the clinical outcomes of patients treated medically after angiography with those of patients who underwent revascularization, within groups defined by ratings of the degree of appropriateness of revascularization in varying clinical circumstances. METHODS: This was a prospective study of consecutive patients undergoing coronary angiography at three London hospitals. Before patients were recruited, a nine-member expert panel rated the appropriateness of percutaneous transluminal coronary angioplasty (PTCA) and coronary-artery bypass grafting (CABG) on a nine-point scale (with 1 denoting highly inappropriate and 9 denoting highly appropriate) for specific clinical indications. These ratings were then applied to a population of patients with coronary artery disease. However, the patients were treated without regard to the ratings. A total of 2552 patients were followed for a median of 30 months after angiography. RESULTS: Of 908 patients with indications for which PTCA was rated appropriate (score, 7 to 9), 34 percent were treated medically; these patients were more likely to have angina at follow-up than those who underwent PTCA (odds ratio, 1.97; 95 percent confidence interval, 1.29 to 3.00). Of 1353 patients with indications for which CABG was considered appropriate, 26 percent were treated medically; they were more likely than those who underwent CABG to die or have a nonfatal myocardial infarction--the composite primary outcome (hazard ratio, 4.08; 95 percent confidence interval, 2.82 to 5.93)--and to have angina (odds ratio, 3.03; 95 percent confidence interval, 2.08 to 4.42). Furthermore, there was a graded relation between rating and outcome over the entire scale of appropriateness (P for linear trend=0.002). CONCLUSIONS: On the basis of the ratings of the expert panel, we identified substantial underuse of coronary revascularization among patients who were considered appropriate candidates for these procedures. Underuse was associated with adverse clinical outcomes.     

Combined off-pump coronary revascularization and lung resection

Concomittant severe coronary artery disease and lung malignancies occur rarely. Combined conventional coronary artery bypass grafting (CABG) with the use of cardiopulmonary bypass (CPB) with lung resection posses several perioperative and postoperative problems related to extracorporeal circulation and heparinization. The avoidance of CPB may be advantageous by decreasing blood loss, pulmonary complications and hospital stay. Further, exposure to the immunosuppressive and inflammatory effects of CPB may have deleterious impact on tumor growth and dissemination. Off-pump CABG makes the combined procedure safer as it abolishes the complications of CPB. We report two patients with the diagnosis of severe coronary artery disease and lung malignancies, underwent off-pump CABG and lung resections in the same surgical setting.     

Drug-eluting stents for coronary artery disease: a review

Over the past decade the introduction of drug-eluting stents (DESs) has revolutionised the treatment of coronary artery disease. However, in recent years concern has arisen over the long-term safety and efficacy of DESs due to the occurrence of late adverse clinical events such as stent thrombosis. With this concern in mind, research and development is currently centred on increasing the long-term safety and efficacy of DESs. The aim of this paper is to provide a thorough review of currently approved and promising investigational DESs. With dozens of companies involved in the development of new and innovative anti-restenotic agents, polymeric coatings and stent platforms, it is intended that this review paper will provide a clear indication of how DESs are currently evolving and prove a valuable reference tool for future research in this area.     

Multiobjective design optimisation of coronary stents

We present here a multi-objective and multi-disciplinary coronary stent design optimization paradigm. Coronary stents are tubular, often mesh-like, structures which are deployed in diseased (stenosed) artery segments to provide a scaffolding feature that compresses atheromatus plaque, hence restoring luminal area and maintaining vessel patency. A three variable geometry parameterisation of a CYPHER (Cordis Corporation, Johnson & Johnson co.) type stent is proposed to explore the functionality of a sequence of circumferential rings connected by 'n' shaped links. The performance of each design is measured by six figures of merit (objectives/metrics) representing (i) acute recoil, (ii) tissue stresses, (iii) haemodynamic disturbance, (iv) drug delivery, (v) uniformity of drug distribution, and (vi) flexibility. These metrics are obtained from computational simulations of (i) structural deformation through balloon inflated expansion of a stent into contact with a stenosed vessel, (ii) pulsatile flow over the deformed stent embedded in the vessel wall, (iii) steady-state drug distribution into the tissue, and (iv) flexibility of a stent in response to an applied moment. Design improvement is obtained by a multi-objective surrogate modelling approach using a non-dominated sorting genetic algorithm (NSGA-II) to search for an optimal family of designs. A number of trade-offs between the different objectives are identified. In particular a conflict between pairs of the following objectives are shown -- (a) volume average stress vs. recoil, (b) volume average drug vs. volume average stress, (c) flexibility vs. volume average stress, (d) flexibility vs. haemodynamic disturbance, (e) volume average drug vs. haemodynamic disturbance, and (f) uniformity of drug vs. volume average stress. Different paradigms to choose the optimal designs from the obtained Pareto fronts are presented and under each such paradigm, the optimal designs and there relative positions with respect to a representative CYPHER stent are shown. The methodology and the results of this work could potentially be useful in further optimisation studies and development of a family of stents with increased resistance to in-stent restenosis and thrombosis.