Research on the Status Quo and Optimization of Centralized Procurement of Coronary Stents

Objective To study the impact of the first national centralized procurement of coronary stents on patients’psychology,the economy of medical institutions,and the survival and development of the coronary stents industry,and to provide suggestions on perfecting procedures to better carry out the centralized procurement of coronary stents.Methods Literature analysis was used to investigate the results of the procurement of coronary stent in a province and a hospital.Results and Conclusion The centralized procurement of coronary stents has alleviated the economic pressure of patients,but it has many problems.Therefore,this paper proposes some suggestions,such as promoting the orderly development of the coronary stent industry,improving the evaluation link of the centralized procurement of coronary stents,adopting the accurate reporting model to ensure the quality of coronary stents and improving the standardization of clinical services.

Cell Area and Strut Distribution Changes of Bent Coronary Stents:A Finite Element Analysis

Coronary stents are metal coils or mesh tubes delivered to blocked vessels through catheters, whic Recently, special drugs h are expanded by balloons to reopen and scaffold target vessels. are carried by stents （drug-eluting stents） to further reduce instent restenosis rate after stenting procedure. However, continual study on biomechanical characteristics of stents is necessary provide a more suitable drug loading for better interactions between stents and tissue, or to platform for drug-eluting stents. The purpose of this paper is to show how finite element methods can be used to study cell area and strut distribution changes of bent coronary stents. A same bending deformation was applied to two commercial coronary stent models by a rigid curved vessel. Results show that the stent design influenced the changes of cell area and strut distribution under bending situation. The stent with links had more cell area changes at outer curvature, and the stent with peak-peak （ 〉 〈 ） strut design could have strut contact and overlapping at inner curvature. In conclusion, this finite element method can be used to study and compare cell area and strut distribution changes of bent stents, and to provide a convenient tool for designers in testing and improving biomechanical characteristics of new stents.

In vitro Study on a New High Nitrogen Nickel-free Austenitic Stainless Steel for Coronary Stents

Most commercialized coronary stents are made of 316L stainless steels due to its good combination of properties, and currently some new stents are made of cobalt-based alloy owing to its higher mechanical properties. However, the presence of high quantity of nickel and/or cobalt elements in these materials, which are known to trigger the toxic and allergic responses, has caused many concerns. Nickel-free austenitic stainless steels have been developed in order to solve these problems. In this paper, based on the development of a new Fe- Cr-Mn-Mo-N type high nitrogen nickel-free austenitic stainless steel, properties such as mechanical property, corrosion resistance in Hankls solution, and in vitro blood compatibility including the kinetic clotting time and the platelets adhesion, were investigated in comparison to the above two conventional materials, a 316L stainless steel and a Co-28Cr-6Mo alloy. The results showed that the new high nitrogen steel possessed better combination of mechanical properties, corrosion resistance and blood compatibility than those of 316L steel and the Co-28Cr-OMo alloy, and can be a promising alternative material for manufacture of coronary stents.

Effects of systematic cardiac rehabilitation training in elderly patients with unstable angina following cardiac stent implantation

BACKGROUND Coronary stent implantation is usually used to treat unstable angina to alleviate stenosis or occlusion,promoting blood flow restoration and alleviating symptoms such as myocardial ischemia.And postoperative cardiac rehabilitation is essential for enhancing recovery and prognosis.Nevertheless,conventional rehabilitation lacks specificity,particularly for elderly patients with multiple comorbidities and poor compliance,rendering it less effective.AIM To investigate the effects of systematic cardiac rehabilitation training in elderly patients with unstable angina following coronary stenting intervention.METHODS A retrospective enrollment was conducted comprising fifty-four elderly patients with unstable angina pectoris who underwent systematic cardiac rehabilitation training after receiving coronary intervention as the rehabilitation group,while fifty-three elderly patients who received basic nursing and rehabilitation guidance measures after coronary intervention were assigned to the control group.Differences in Seattle Angina Questionnaire scores,survival quality(SF-36)scores,cardiopulmonary exercise function assessment index,echocardiographic cardiac function index,and adverse cardiovascular events were compared between the two groups.RESULTS After intervention,the rehabilitation group observed greater VO2 Max,maximum metabolic equivalent,eft ventricular ejection fraction,left ventricular end-diastolic diameter and smaller left ventricular end-systolic diameter.And the rehabilitation group observed greater scores of physical activity limitation,stable angina pectoris,treatment satisfaction,and SF-36 score.The incidence of adverse cardiovascular events in the two groups,showed no significant difference.CONCLUSION Systematic cardiac rehabilitation following coronary stenting in elderly patients with unstable angina pectoris can enhance cardiac function recovery,consequently enhancing both quality of life and cardiopulmonary exercise tolerance.

Evaluation of Clinical Outcomes of ses Stent in Patients with Coronary Artery Disease After Intracoronary Stenting in Small Vessels

Background:Limited data are available for sirolimus-eluting stent(SES,Cypher)implantation in patients with coronary artery disease in small vessels.The clinical longtermoutcomes of SES in patients with coronary artery disease after intracoronary stenting in small vessels has not been yet evaluated.

Percutaneous coronary intervention of totally occluded coronary venous bypass grafts:An exercise in futility?

BACKGROUND Percutaneous coronary intervention(PCI)of diseased saphenous vein grafts(SVG)continues to pose a clinical challenge.Current PCI guidelines give a class III recommendation against performing PCI on chronically occluded SVG.However,contemporary outcomes after SVG intervention have incrementally improved with distal protection devices,intracoronary vasodilators,drug-eluting stents,and prolonged dual antiplatelet therapy.AIM To reassess the procedural and long-term outcomes of PCI for totally occluded SVG with contemporary techniques.METHODS This was a retrospective observational study conducted at a single university hospital.The study population consisted of 35 consecutive patients undergoing PCI of totally occluded SVG.Post-procedure dual antiplatelet therapy was continued for a minimum of one year and aspirin was continued indefinitely.Clinical outcomes were assessed at a mean follow-up of 1221±1038 d.The primary outcome was freedom from a major adverse cardiac event(MACE)defined as the occurrence of any of the following:death,myocardial infarction,stroke,repeat bypass surgery,repeat PCI,or graft reocclusion.RESULTS The study group included 29 men and 6 women with a mean age of 69±12 years.Diabetes was present in 14(40%)patients.All patients had Canadian Heart Classification class III or IV angina.Clinical presentation was an acute coronary syndrome in 34(97%)patients.Mean SVG age was 12±5 years.Estimated duration of occlusion was acute(<24 h)in 34%of patients,subacute(>24 h to 30 d)in 26%,and late(>30 d)in 40%.PCI was initially successful in 29/35 SVG occlusions(83%).Total stent length was 52±35 mm.Intraprocedural complications of distal embolization or no-reflow occurred in 6(17%)patients.During longer term follow-up,MACE-free survival was only 30%at 3 years and 17%at 5 years.CONCLUSION PCI of totally occluded SVG can be performed with a high procedural success rate.However,its clinical utility remains limited by poor follow-up outcomes.

Efficacy and safety of individually tailored antiplatelet therapy in patients with acute coronary syndrome after coronary stenting： a single center, randomized, feasibility study

Background Low responsiveness to clopidogrel （LRC） is associated with increased risk of ischemic events. This study was aimed to explore the feasibility of tailored antiplatelet therapy according to the responsiveness to clopidogrel. Methods A total of 305 clopidogrel naive patients with acute coronary syndromes （ACS） undergoing coronary stenting were randomly assigned to receive standard （n = 151） or tailored （n = 154） antiplatelet therapy. The ADP-induced platelet aggregation tests by light transmission aggregometry were performed to identify LRC patients assigned to the tailored group. The standard antiplatelet regimen was dual antiplatelet therapy with aspirin and clopidogrel. The tailored antiplatelet therapy was standard regimen for non-LRC patients and an additional 6-month cilostazol treatment for LRC patients. The primary efficacy outcome was the composite of cardiovascular death, myocardial infarction or stroke at one year. Results LCR was present in 26.6% （41/154） of patients in the tailored group. The percentage platelet aggregation for LCR patients was significantly decreased at three days after adjunctive cilostazol treatment （77.5% ± 12.1% vs. 64.5% ± 12.1%, P 〈 0.001）. At one year follow-up, a non-significant 37% relative risk reduction of primary events were observed in the tailored group as compared to the standard group （5.8% vs. 9.3%, P = 0.257）. There were no differences in the rates of stent thrombosis and hemorrhagic events between the two groups. Conclusions Tailored antiplatelet therapy for ACS patients after coronary stenting according to responsiveness to clopidogrel is feasible. However, its efficacy and safety need further confirmation by clinical trials with larger sample sizes.

Comparison of clinical outcomes of Chinese men and women after coronary stenting for coronary artery disease:a multi-center retrospective analysis of 4,334 patients

The outcome differences between Chinese male and female patients within one-year follow-up after percutaneous coronary intervention（PCI） with stent remain unclear.The present study was aimed to compare clinical outcomes in such two populations.From May 1999 to December 2009,4,334 patients with acute myocardial infarction（MI）,unstable angina,stable angina,or silent ischemia,who underwent PCI,were registered at our centers.Among these,3,089 were men and 1,245 were women.We compared these groups with respect to the primary outcomes of MI and secondary outcomes including a composite of major adverse cardiac events（MACE） including cardiac death,MI,target lesion revascularization,target vessel revascularization（TVR）,stent thrombosis（ST）,definite ST and probable ST at one-year follow-up.Chinese male patients had a higher MACE rate（13%vs.10.7%,P =0.039）,mainly led by TVR（9.09%vs.6.98%,P=0.024） at one year,which was significantly different than female patients.Chinese male and female patients showed a significant difference on MACEs.However,there was no significant difference with respect to MI between these groups.

Two case of preoperative bridging therapy for patients undergoing non- cardiac surgery after coronary stent implantation

It has been reported that up to 12% of patients underwent non-cardiac surgery or invasive procedures within the first year after the coronary stent implantation. Premature dis- continuation of antiplatelet therapy is associated with a sig- nificant increase in mortality and major adverse cardiac events, in particular, stent thrombosis. Thus, postpone- ment of elective surgery is advocated during the first year after the coronary stent implantation.

Clinical Observation on Antiruisi Prescription (安替瑞丝方) in Preventing Restenosis after Coronary Artery Stenting

Antiruisi (AR)prescription (安替瑞丝方) is a compound in Chinese drug-therapy, which was used to treat 35 patients with coronary heart disease after stenting by the authors, and a satisfactory effect had been proved in preventing restenosis. It is reported as follows.

Long-term follow-up study of elderly patients with covered stent implantation after coronary perforation

ObjectiveTo evaluate the long-term efficacy of covered stent implantation in the treatment of elderly patients with coronary perforation while undergoing percutaneous coronary intervention （PCI）.MethodsFrom June 2004 to June 2012, our center has followed ten elderly patients （age≥ 60 years） who sustained coronary perforation during PCI. The major adverse cardiac events （MACE） were observed as well. The patients were advised to take 75 mg/day Clopidogrel for two years, and indefinite use of 100 mg/day enteric-coated aspirin.ResultsSix out of the 10 patients aged from 60 to 76 years old （mean 68.6 ± 5.2 years） were male, four were female. The average diameter of the implanted stents was 3.3 ± 0.3 mm, and the average length was 22.1 ± 3.7 mm. All the ruptures were successfully sealed without intra-procedural death. The follow-up duration ranged from 0.6 to 67 months （mean 31.7 ± 24.5 months）. One patient died of multiple organ failure due to lung infection in 19 days after PCI; one died of cardiac sudden death in 13 months after PCI; one had angina pectoris in 53 months after PCI; one underwent multi-slice CT examination in six months after PCI, and no in-stent restenosis was found. The other four patients received angiography follow-up, and the results showed that three patients had no intra-stent restenosis, while one had left anterior descending （LAD） restenosis in the covered stent in 67 months after PCI. The in-hospital mortality was 10% （1/10）. The MACE rate in 12 months after PCI was 10% （1/10）. During the entire followed-up period, the restenosis rate in target vessels was 20% （1/5）, mortality was 20% （2/10）, and the MACE rate was 40% （4/10）.ConclusionTreatment of coronary perforation by using covered stents can achieve favorable long-term results; a two-year dual antiplatelet therapy （DAPT） after PCI can effectively prevent intra-stent thrombosis.

“Obesity paradox”in coronary artery disease

Obesity used to be among the more neglected public health problems, but has unfolded as a growing medical and socioeconomic burden of epidemic proportions. Morbid obesity is linked to traditional cardiovascular risk factors like, hypertension, hyperlipidemia and diabetes, and suspected to incur increased morbidity and mortality in the Western and even third world populations. This patient cohort is also at greater risk to develop coronary artery disease. Recent population-based registries revealed that 43% and 24% of all cases of coronary revascularization were carried out in overweight and obese patients, respectively. However, despite evidence of a positive correlation between obesity and increased cardiovascular morbidity, some authors have described a better clinical outcome in overweight and obese patients, a phenomenon they coined "obesity paradoxon". Thus, there is an ongoing debate in light of conflicting data and the possibility of confounding bias causing misconception and challenging the "obesity paradox". In this review article we present the current evidence and throughly discuss the validity of the "obesity paradoxon" in a variety of clinical settings.

CLINICAL APPLICATION OF INTRACORONARY STENTING

Intracoronary stents were implanted in 61 patients(58 males and 3females,aged 52.1±8.3 years) with coronary heart disease in thishospital from June 1995 to May 1998.Seventy-two intracoronary stents (12Palmaz-Schatz.8 OR-I,45 Multilink,6 NIR and 1 Wiktor-i) were implanted,45 in LAD(62.5% ),22 in RCA(30.6%) and 5 in LCX(6.9%),Indications forstenting included 30 de novo(41.6%).4 bail-out(5.6%)and 38 Suboptimal(52.8%)stenting.The procedure success rate was 100%.Averagediameterstenosis decreased from 75-100% to -10-10% after stenting.There was one death from subacute stent thrombosis Two cases hadhematoma at the pancture site.There were no complication of acutethrombosis,cerebral hemorrhage and emergency CABG.During 1-36 monthsfollow-up,6 cases had relapse of chest pain,incinding 4 case ofrestenosis proved by argiography.Coronary stenting is a successfulmeans for atent"stand-by" and bail-out procedure for balloon angioplasty.Optimal angiographic results can be achieved in the majority ofpatients by proper stent sizing and deployment techniques.Anticoagulation should be given according to the characteristics oflesions and post-stenting angiographic findings so as to reducevascular and bleeding complications as well as hospital stay followingcoronary angioplasty.The results suggest that intracoronary stentinghas high success rate and low restenosis rate.It is an effective andsafe interventional therapy for acute coronary closure or selected denovo complex lesions following PTCA.

Sirolimus-eluting stent fractures associated with aneurysm and very late stent thrombosis in the right coronary artery

Although the occurrence of coronary stent fracture is rare,recent reports showed that stent fracture after sirolimus-eluting stent(SES)implantation may be associated with neointimal hyperplasia and restenosis.We report two cases of stent fracture that occurred late after elective SES implantation into the right coronary artery(RCA)that were related to the aneurysm,restenosis,thrombosis,and vessel occlusion.……

Dissecting Sub-epicardial Hematoma Due to Coronary Perforation and Non-developing Stent

We report a 65-year-old man who presented with anastomotic perforation of the distal right coronary artery due to stent deployment, complicated by a small and stable dissecting sub-epicardial hematoma, and non-developing stent. The cause was unknown.

SUCCESSFUL TREATMENT OF CORONARY ARTERY PERFORATION WITH EMERGENCY INTRACORONARY COATED STENT IMPLANTATION

Coronary artery perforation is a rare but catatrophic complication of percutaneous coronary intervention.We report a case of type Ⅲ coronary artery perforation following stenting at calcified mid-segment of left anterior descending artery.The perforation was successfully covered using a PTFE-coated stent with an excellent clinical and angiographic outcomes.

Sirolimus-eluting Stent for the Treatment of Small Coronary Artery Lesions:Comparison between Cypher and Firebird Stent

Objectives To evaluate the effectiveness of firebird stent for the treatment of coronary de novo lesion compared with cypher stent. Methods Ninety-one consecutive patients with 156 lesions who underwent coronary cypher (n = 68 lesions) and firebird (n = 88 lesions) implantation, quantitative coronary angiography (QCA) was performed at the time of stent implantation and subsequently at 8 months post-stenting. Small vessel disease was defined as ≤2.5 mm of reference vessel diameter measured by QCA. Major adverse cardiac events (MACE) including death, thrombosis, nonfatal myocardial infarction and target lesion revascularization (TLR) were compared between the two groups. Results Baseline clinical characteristics and angiographic parameters were similar between the two groups. Seven-month angiographic follow-up, the late loss was not different between the two groups (0.14 ± 0.38 mm vs 0.13 ± 0.17 mm, P > 0.05). Similarly, overall thrombosis rate were similar in both groups (1.5% vs 1.1%, P > 0.05). However, in-stent restenosis as well as in-segment restenosis rate were significantly higher in cypher group than that in firebird group (4.4% vs 0% and 19.1% vs 3.4%, P = 0.047 and P = 0.001 respectively). TLR was also higher in the cypher group (10.3% vs 2.3%, P = 0.033) compared with firebird group. Conclusions In this small sample size, non-randomized study, the data indicated that implantation of firebird stent for the treatment of small coronary lesion showed more favorable results in respective of restenosis compared with cypher stent implantation. A multi-center, large-sample size, randomized study, therefore, may be warranted.

Comparison of Results of Coronary Angioplasty in Patients with Unstable vs. Stable Angina

Objectives To compare the short and mid - term outcomes in cases of percutaneous transluminal coronary angioplasty (PTCA) in patients with unstable v stable angina. Methods Patients selected for PTCA/stenting were divided in to two groups, one with stable angina pectoris (SA group, n = 92) and one with unstable angina pectoris (UA group, n = 112). The outcomes of coronary an giographies (CAG), initial (30-d) success of the procedure, and follow - up status in the two groups were compared. Results Baseline characteristics were similar, although the patients with unstable symptoms more females ( P< 0. 05), and had a higher average CCS class (P< 0. 05) and a higher incidence of postinfarction angina ( P< 0. 01). The frequency of ' complex stenosis in patients with unstable angina was higher than that of patients with stable angina, 33% v 20% ( P< 0. 01). A total of 309 vessels ac cepted the procedure; including 210 stents were sue cessfully delivered to 156 patients. 143 and 67 stents were implanted in the UA and SA group, respectively ( P< 0. 01 ) . No major complication occurred in the two groups, except 12 patients experienced reoccur ring chest pain initially, 9 in UA group v 3 in SA group ( P< 0. 05). The averaged six - month follow -up status was compared too. Only 3 cases developed myocardial infarction, including 2 patients with unsta ble angina. 12 and 16 reoccurring chest pains were found in the two groups, respectively ( 13% in SA group vs 14% in UA group). There were no signifi cant differences between groups in rates of clinical restenosis, follow - up angina class, or overall clinical success. Conclusions Patients with unstable angina receiving PTCA/stenting have similar complication, restenosis, and initial and midterm success rate as compared to patients with stable symptoms with strict cases select and careful preparation.

Multivariate Analysis of Clinical Factors in Restenosis after Coronary Stenting

Ojbective To find the independent predictors for restenosis after coronary stenting. Methods Quantitative angiography was performed on 60 cases (67 successfully dilated lesions) after angio-plasty over 6-months follow-up, and both univariate and multivariate logistic regression analysis were done to i-dentify the correlations of restenosis with clinical factors. Results The total restenosis rate was 31. 3% (21 of 67 lesions), and according to univariate analysis the patients who underwent coronary stenting≥ 3. 5mm had a lower rate of restenosis ( P < 0. 01). Collateral circulation to the obstruction site, high maximal inflation pressure, smoking and the less minimal lumen diameter after PTCA made the rate of restenosis higherower ( P < 0. 05) . Multivariate logistic regression analysis showed that coronary stenting ≥3. 5mm had a low rate of restenosis, but high maximal inflation pressure and smoking made the restenosis rate higher. Conclusion Coronary stent size, maximal inflation pressure and. smoking were independent predictors for restenosis.

Short-term safety and effects of a novel fully bioabsorable poly-L-lactic acid sirolimus-eluting stents in porcine coronary arteries

The role of drug-eluting stent （DES）, which prevents acute or subacute recoil and elutes drugs to prevent smooth muscle cell proliferation, is temporary and limited within a few weeks after its implantation. Beyond that, there is no utility or advantages but only limitations just like foreign materials in patients＇ body. All of these problems can be solved with the use of fully bioabsorbable stent （BAS）,