雷帕霉素与紫杉醇洗脱支架置入治疗冠状动脉病变的有效性

背景：药物洗脱支架置入治疗冠状动脉病变具有良好的临床效果,但不同支架的治疗效果可能存在一定差异。 目的：比较不同支架置入治疗冠状动脉病变的临床效果。 方法：纳入278例冠状动脉病变患者,均接受冠状动脉支架置入治疗,其中91例置入雷帕霉素洗脱支架,92例置入紫杉醇洗脱支架,95例置入裸金属支架。支架置入后随访12个月,记录死亡和心肌梗死等不良心脏事件发生情况,以及冠状动脉再狭窄发生情况及材料宿主反应。 结果与结论：雷帕霉素洗脱支架组与紫杉醇洗脱支架组冠状动脉再狭窄率、急性心肌梗死发生率、冠状动脉旁路移植或再次经皮冠状动脉介入治疗率均低于裸金属支架组(P < 0.05),雷帕霉素洗脱支架组与紫杉醇洗脱支架组上述指标比较差异均无显著性意义(P > 0.05)。3组死亡率比较差异无显著性意义(P > 0.05)。3组均未发生支架移位、脱落、断裂、置入位置不良及白细胞增多和血小板减少、溶血等情况。表明两种药物洗脱支架的治疗效果相当,均优于裸金属支架。  中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

MicroRNA在冠状动脉疾病诊断和治疗中的应用

冠状动脉疾病(coronary artery disease,CAD)也称为动脉硬化症,它是因脂肪斑块在心血管内积聚而引起的疾病,心脏动脉的粥样硬化是其潜在致病原因。研究发现多种血液标志物与CAD的风险增加相关,其中微小RNA(microRNA,miRNA)是一类小的非编码核糖核酸分子,长度约为20～22 bp,在心脏...     

完全生物可降解冠状动脉支架的研究现况与展望

文章对完全生物可降解冠状动脉支架设计概念作了说明,就生物可降解冠状动脉支架材料如镁合金、铁、聚合材料等研究进展作详细论述,介绍了完全生物可降解冠状动脉支架临床应用进展,探讨其在临床治疗上的发展前景.     

Homocysteine, fibrinogen and physical activity in human males with coronary artery disease

Elevated homocysteine (Hcy) concentration has been identified as an independent risk factor for premature coronary artery disease (CAD). Associations between Hcy concentrations and established cardiovascular risk factors have occasionally, but not consistently, been demonstrated. Plasma fibrinogen and total Hcy concentrations, along with other risk factors, folate and B-vitamin supplements and medications, were recorded for 40 males (mean age±SD: 65±9.8 years) with CAD. Physical activity was assessed using the Modifiable Activity Questionnaire (MAQ), a written questionnaire which appraises leisure and occupational activities by recall for a 12-month period. Subjects in the upper tertile of physical activity had significantly lower fibrinogen concentrations than those in the lower tertile (274.7±38 mg/dl vs. 320.2±63, respectively,p-0.04). Univariate analyses revealed those subjects on beta-blocker therapy (n=12) had lower fibrinogen concentrations than those not on these medications (n=28) (277.7±16.7 vs. 316.1±10.9 mg/dl respectively,p=0.04). There was also a trend for those on beta-blockade to have lower Hcy concentrations (8.3±0.66 vs 9.7±0.43 μmol/l, respectively,p=0.058). Homocysteine concentration was found to be positively associated with age (p=0.0008). No significant associations were established with multivariate analyses among fibrinogen. Hcy, physical activity, age, BMI, B-vitamin and folate supplements, beta-blocker therapy, total cholesterol, high density lipoprotein (HDL), low density protein (LDL), triglycerides, and TC/HDL ratio. These results support the hypothesis that hyperhomocysteinaemia is independent of other CAD risk factors. Future studies should consider the favourable effects of beta-blockade, which may be a confounding factor, on Hcy and fibrinogen concentrations. Knowledge of associations may contribute towards understanding of the pathogenesis of CAD.     

Influence of the time of day on physical performance in patients with coronary artery disease

The exercise training workload for cardiac patients is determined from the peak heart rate achieved safely during a stress test. Circadian rhythms may play a key role in changing physiological responses to the stress test. Therefore, the purpose of this study was to evaluate the influence of the time of day on cardiopulmonary and metabolic responses in highly trained men with coronary artery disease. A group of 15 patients with coronary artery disease [53.5 (SD 6) years] performed two sessions of graded tests to exhaustion: one session was performed at 10 a.m. and the second at 5 p.m. in randomized order. Treadmill velocity was kept constant at a speed of 4.8 km · h^–1 starting with an elevation of 0% which was increased thereafter by 2.5% every 3 min. At rest the results revealed that only oxygen uptake was significantly lower (P < 0.05) in the morning compared to that observed in the evening [2.9 (SD 0.4) compared to 3.5 (SD 0.5) ml O₂ · kg^–1 · min^–1, respectively]. During exercise, differences due to time of day were found in the variables of maximal oxygen uptake which were significantly higher (P < 0.05) in the evening than in the morning [34.2 (SD 2.6) and 40.8 (SD 2.5) ml O₂ · kg^–1 · min^–1, respectively]. These data indicated that in these well-trained coronary artery disease patients there was a significant time of day effect associated with metabolic responses following stress-testing.     

Simulation of longitudinal stent deformation in a patient-specific coronary artery

In percutaneous coronary intervention (PCI), stent malapposition is a common complication often leading to stent thrombosis (ST). More recently, it has also been associated with longitudinal stent deformation (LSD) normally occurring through contact of a post balloon catheter tip and the protruding malapposed stent struts.The aim of this study was to assess the longitudinal integrity of first and second generation drug eluting stents in a patient specific coronary artery segment and to compare the range of variation of applied loads with those reported elsewhere. We successfully validated computational models of three drug-eluting stent designs when assessed for longitudinal deformation. We then reconstructed a patient specific stenosed right coronary artery segment by fusing angiographic and intravascular ultrasound (IVUS) images from a real case. Within this model the mechanical behaviour of the same stents along with a modified device was compared. Specifically, after the deployment of each device, a compressive point load of 0.3 N was applied on the most malapposed strut proximally to the models. Results indicate that predicted stent longitudinal strength (i) is significantly different between the stent platforms in a manner consistent with physical testing in a laboratory environment, (ii) shows a smaller range of variation for simulations of in vivo performance relative to models of in vitro experiments, and (iii) the modified stent design demonstrated considerably higher longitudinal integrity. Interestingly, stent longitudinal stability may differ drastically after a localised in vivo force compared to a distributed in vitro force.     

不同心血管支架材料对老年冠心病患者内皮素和血管再狭窄的影响

背景：支架置入是治疗冠心病的有效方法。 目的：探讨不同心血管支架材料对老年冠状动脉粥样硬化性心脏病患者血管狭窄及血管内皮素含量的影响。 方法：由第一作者应用计算机检索维普数据网1995-01/2011-06文章。检索关键词为“心血管支架,老年冠心病,内皮素,血管再狭窄”。 结果与结论：单纯球囊扩张治疗老年冠心病患者漫性血管病变、血管壁损伤、血栓形成、炎性刺激的各种生长因子和细胞因子的产生较中青年明显增多,术后中远期靶血管再狭窄率比中青年高;金属裸支架置入降低了单纯球囊扩张靶血管再狭窄的发生率及血栓形成、各种生长因子和细胞因子的产生,改善了中远期靶血管再狭窄率;药物支架有效制止了血管弹性回缩和负性重塑,使老年冠心病支架置入中远期靶血管再狭窄率显著下降,减少了并发症的发生,改善了老年冠心病患者的生活质量。     

Histologic analysis of a covered stent implanted for pseudoaneurysm in a coronary artery

Covered stents are the standard of care when coronary perforations complicate percutaneous coronary interventions and have also been utilized in the treatment of coronary aneurysms. We present the clinical and histologic features of a patient who developed a coronary perforation and pseudoaneurysm 4 years following deployment of intracoronary stents. Although the covered stent successfully sealed the perforation, subsequent thrombosis led to a fatal acute myocardial infarction.     

Bioactive coronary stent coating based on layer-by-layer technology for siRNA release

One procedure to treat stenotic coronary arteries is the percutaneous transluminal coronary angioplasty (PTCA). In recent years, drug-eluting stents (DESs) have demonstrated elaborate ways to improve outcomes of intravascular interventions. To enhance DESs, the idea has evolved to design stents that elute specific small interfering RNA (siRNA) for better vascular wall regeneration. Layer-by-layer (LbL) technology offers the possibility of incorporating siRNA nanoplexes (NPs) to achieve bioactive medical implant coatings. The LbL technique was used to achieve hyaluronic acid/chitosan (HA/Chi) films with incorporated Chi-siRNA NPs. The multilayer growth was monitored by quartz crystal microbalance. The coating on the stents and its thickness were analyzed using fluorescence and scanning electron microscopy. All stents showed a homogeneous coating, and the polyelectrolyte multilayers (PEMs) were not disrupted after ethylene oxide sterilization or expansion. The in vitro uptake of fluorescent-labeled NPs from PEMs in primary human endothelial cells (ECs) was analyzed by flow cytometry for 2, 6 and 9 days. Furthermore, stents coated with HA/Chi and Chi-siRNA NPs were expanded into porcine arteries and showed ex vivo delivery of NPs. The films showed no critical results in terms of hemocompatibility. This study demonstrates that Chi-siRNA NPs can be incorporated into PEMs consisting of HA and Chi. We conclude that the NPs were delivered to ECs under in vitro conditions. Furthermore, under ex vivo conditions, NPs were transferred into porcine artery walls. Due to their good hemocompatibility, they might make an innovative tool for achieving bioactive coatings for coronary stents.     

Testosterone and coronary artery disease in men

Coronary artery disease (CAD) is the leading cardiovascular cause of death, and in men, endogenous testosterone concentrations are inversely related to the extent and severity of CAD. Testosterone is known to affect a number of risk factors for CAD and has effects on vascular tone, vasoreactivity and blood flow of blood vessels beyond the reproductive system, indicating that testosterone may be involved in the pathogenesis of CAD. In this review we will present and discuss the actions of endogenous testosterone and testosterone treatment on risk factors for CAD, on the blood vessel wall and blood flow, and on atheroma development and progression, and discuss the potential for testosterone use in men with CAD.     

冠脉支架与血管耦合作用的有限元分析

目的研究支架扩张直径以及斑块硬化程度对支架与冠脉耦合扩张的影响,探究合理的支架扩张直径范围,以期对临床冠脉支架植入术提供科学的参考依据。方法首先采用三维设计软件建立支架和理想狭窄冠状动脉模型,再利用有限元分析软件,通过赋予冠脉斑块3种不同的材料属性(钙化、纤维化、脂质),参考健康冠脉内径尺寸,模拟分析支架分别扩张至冠脉直径的1.0、1.1、1.2、1.3倍时,支架和血管的应力、支架径向回弹率、冠脉最小腔径以及支架的贴壁情况。结果支架、血管壁和斑块上的最大应力、支架径向回弹率、冠脉最小腔径均随支架扩张直径增加而增加。当支架扩张至冠脉直径的1.3倍时,血管壁及钙化斑块上的最大应力已处于或超出极限应力范围;当支架扩张至冠脉直径的1.0倍时,支架卸载回弹后会出现明显的贴壁不良。相比其他两种斑块,钙化斑块导致更高的血管应力和更小的血管腔径增长。结论冠脉支架扩张比例范围在1.1~1.2倍较为合理;其中,含钙化斑块的冠脉,应将支架扩张比例控制在1.1倍更为合理。研究结果可为冠脉支架植入术中支架扩张直径的选择提供参考依据。     

X-ray micro-tomography of a coronary stent deployed in a model artery

Coronary stents are small scaffolds routinely implanted during angioplasty procedures to re-open coronary arteries which have become narrowed by an atherosclerotic plaque. Despite the advent of drug-eluting stents to reduce restenosis (re-narrowing) after the procedure, complications still arise and mechanical factors may be partly the cause. Stents are being used in increasingly complex cases, so new forms of pre-clinical testing may be helpful in evaluating stent designs and deployment techniques. With this in mind, an in vitro experiment was conducted to evaluate the use of X-ray micro-tomography to image stents at various stages of deployment. A stent was deployed in an artificial artery while using a synchrotron X-ray source to obtain the tomography scans. A volume element (voxel) size of 5.3 μm was achieved, with a vertical field of view of 4.5 mm. The imaging of the stent and artificial artery materials was better than expected, despite some attenuation artifacts and the high monochromatic beam energy used (25 keV). Experimental problems are discussed, together with recommendations for improving the technique. It is intended that this technique will be of interest to engineers and clinicians as a pre-clinical test.     

Comparison of coronary artery bypass grafting with percutaneous coronary intervention for unprotected left main coronary artery disease

Purpose

Coronary artery bypass grafting (CABG) is the optimal treatment option for left main coronary artery disease (LMCAD). However, LMCAD remains a constant topic of discussion between cardiac surgeons and interventional cardiologists. The aim of this study was to assess the efficacy of LMCAD treatments by comparing the mid-term outcomes of CABG and percutaneous coronary intervention (PCI) using bare metal stents or drug-eluting stents (DESs).

Materials and Methods

The study population was comprised of 199 consecutive patients admitted with unprotected LMCAD. All of the patients were assigned to PCI (88 patients) or CABG (111 patients). The primary clinical end point indicated death, stroke of acute coronary syndrome (ACS).

Results

Patients assigned to PCI were at higher operative risk than patients scheduled for CABG (6.49±4.09 vs. 4.81±2.67, p=0.0032). Comparison of the group that received DESs with the CABG group did not reveal any differences in major adverse cardio-cerebral events (MACCE) occurrence (21% vs. 16%, p=NS). Patients in the CABG and PCI groups died with similar frequency (11% vs. 16%, p=NS). The mortality rate in the CABG group was higher than among those treated with DES (11% vs. 3%, p=0.049). The rate of ACS was higher in the PCI group than in the CABG group (13% vs. 4%, p=0.016).

Conclusion

Despite the fact that patients treated with PCI were at higher operative risk, PCI with DES was shown to be comparable to CABG in terms of mortality, stroke and ACS. However, the frequency of repeat revascularizations remains a constant concern with PCI.