nitinol and Myocardial-Infarction

The primary purpose of this study was the composite of major adverse events through 30 days post-index procedure or ipsilateral stroke from 30 days to 1 year (365 days). Presented here is the composite of death, stroke, and myocardial infarction (MI) through 30 days.. Rates of minor stroke have been higher with carotid artery stenting (CAS) compared with carotid endarterectomy (CEA). The study hypothesized that a stent with mesh covering may improve plaque stabilization during CAS, reduce plaque protrusion, and lead to reduced stroke rates.. The SCAFFOLD trial, a prospective, multicenter, single-arm clinical trial evaluating the GORE carotid stent (GCS), enrolled patients at increased risk for adverse events from CEA with severe carotid artery stenosis (defined as symptomatic ≥50% or asymptomatic ≥80%). The SCAFFOLD trial screening committee was implemented to determine adherence to the study protocol. Patients were evaluated for the primary endpoint, the composite of death, stroke, and MI through 30 days.. A total of 312 patients were enrolled, treated, and reviewed by the SCAFFOLD trial screening committee, of which 265 were included in the primary analysis population. The 30-day rate of death, stroke, or MI was 3.0% (95% confidence interval: 1.3% to 5.9%) and the stroke or death rate was 1.5%. The 30-day stroke rate was 1.1%. The 2 deaths in the study were not stroke related.. Low death, stroke, or MI rates were demonstrated with GCS in patients at high risk for CEA. The 30-day stroke rate of 1.1% suggests that the carotid stent mesh covering may reduce the neurologic events associated with CAS when used in appropriately selected patients.

Topics: Aged; Aged, 80 and over; Alloys; Carotid Stenosis; Endarterectomy, Carotid; Endovascular Procedures; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Prosthesis Design; Risk Assessment; Risk Factors; Self Expandable Metallic Stents; Severity of Illness Index; Stroke; Time Factors; Treatment Outcome; United States

Primary percutaneous coronary intervention (PCI) has considerably improved clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) when compared with thrombolytic therapy. Prognosis after primary PCI might be further improved by decreasing stent-related complications such as stent thrombosis. The STENTYS self-apposing stent has been shown to be superior compared with balloon-expandable stents with regard to stent apposition. The current prospective randomized trial was designed to evaluate whether the superior stent apposition of the STENTYS stent results in clinical outcomes that are at least noninferior to a conventional balloon-expandable stent.. The APPOSITION V is a prospective, multicenter, international, single-blinded, randomized controlled trial in STEMI patients. Randomization will be performed in a 2:1 ratio between the self-apposing nitinol bare-metal STENTYS stent and the balloon-expandable bare-metal MULTI-LINK. The primary end point is defined as target vessel failure, which is a composite of cardiac death, target vessel-related recurrent myocardial infarction, or clinically driven target vessel revascularization, at 1-year follow-up. Baseline intravascular ultrasound and optical coherence tomography (OCT) substudies will be performed in 212 and 60 subjects, respectively, and a repeat angiography at 12 to 13 months will be performed in 105 subjects, including intravascular ultrasound and OCT (in the 60 OCT patients). This study is registered on ClinicalTrials.gov with number NCT01732341.. APPOSITION V will be the first randomized trial powered on clinical end points that directly compares the STENTYS self-apposing stent with a conventional balloon-expandable stent in patients presenting with STEMI undergoing primary PCI.

Topics: Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Humans; Myocardial Infarction; Percutaneous Coronary Intervention; Prosthesis Design; Prosthesis Failure; Recurrence; Single-Blind Method; Stents; Tomography, Optical Coherence; Treatment Outcome; Ultrasonography, Interventional

A new martensitic nitinol stent with improved flexibility and radiopacity was tested to evaluate whether these differences improve initial or long-term outcome. Patients who underwent percutaneous revascularization of a discrete native coronary lesion were randomly assigned to the new stent (PARAGON, n = 349) or to the first-generation Palmaz-Schatz (PS) stent (n = 339). The primary end point was target vessel failure at 6 months (a composite of cardiac or noncardiac death, any infarction in the distribution of the treated vessel, or clinically indicated target vessel revascularization). Secondary end points were, among others, device and procedural success and angiographic restenosis. Mean age was 62 years; diabetes was present in 21% of patients, prior bypass surgery in 6%, and recent infarction in 22% (p = NS for comparison between the 2 randomized arms). The PARAGON stent group had smaller reference vessels (2.97 vs 3.05 mm, p = 0.05), more prior restenosis (8.0% vs 4.5%, p = 0.07), and a longer average stent length (21.3 vs 19.4 mm, p < 0.05). Device success was significantly higher in the PARAGON arm (99.1% vs 94.3%, p < 0.05). Death and infarction at 6-month follow-up were infrequent in both groups. There was no significant difference in death (2.0% vs 1.2%, p = 0.546), but a higher rate of infarction for the PARAGON cohort (9.2% vs 4.7%, p = 0.025). Although target vessel failure (20.3% vs 12.4%, p = 0.005) and target lesion revascularization (12.0% vs 5.9%, p = 0.005) were higher in the PARAGON group, there was no significant difference in 6-month follow-up in in-stent minimal lumen diameter or in the rate of binary angiographic restenosis. Both PARAGON and PS stents are safe and associated with infrequent adverse events. The PARAGON stent can be delivered more frequently than the first-generation PS stent. Although there was no significant difference in in-stent minimal lumen diameter or the frequency of angiographic restenosis, clinical restenosis was more frequent in the PARAGON group.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Elasticity; Equipment Design; Equipment Failure; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Infarction; Recurrence; Stainless Steel; Stents; Time Factors; Treatment Outcome

The DURABILITY Iliac clinical study evaluated the safety and effectiveness of 2 nitinol self-expanding stents for the treatment of atherosclerotic common and external iliac artery lesions up to 10 cm in length and >50% stenosis in subjects with Rutherford classification peripheral arterial disease stages 2-4.. DURABILITY Iliac was a prospective, multicenter, core lab adjudicated, nonrandomized clinical study enrolling 75 subjects from 15 sites in the United States and Europe. Clinical follow-up visits were at 30 days, 9 months, and 1, 2, and 3 years after procedure. The primary outcome measured was the major adverse event (MAE) rate at 9 months, defined as a composite of periprocedural death, in-hospital myocardial infarction (MI), clinically driven target lesion revascularization (CD-TLR), and amputation of the treated limb through 9 months after procedure. Secondary outcomes included primary patency rate at 9 months, clinically driven target vessel revascularization (CD-TVR), change in ankle-brachial index, and change in Walking Impairment Questionnaire score at 30 days and 9 months. Device success was defined as the ability to deploy the stent as intended at the treatment site.. The MAE rate at 9 months was 1.3% (1/75), with 1 subject experiencing a CD-TLR. No periprocedural deaths, MIs, or amputations were reported. Primacy patency at 9 months was 95.8%. Freedom from CD-TVR was 98.6% at 9 months. Subjects improved in Walking Impairment Questionnaire scores for all categories (walking impairment, walking speed, walking distance, and stair climbing) at the 30-day and 9-month visit. Device success was 100%.. The 9-month results of the DURABILITY Iliac study demonstrate the safety and effectiveness of 2 nitinol self-expanding stents for the treatment of atherosclerotic lesions of the common and external iliac arteries.

Topics: Aged; Alloys; Ankle Brachial Index; Constriction, Pathologic; Endovascular Procedures; Europe; Exercise Tolerance; Female; Hospital Mortality; Humans; Iliac Artery; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Peripheral Arterial Disease; Prospective Studies; Prosthesis Design; Recovery of Function; Risk Factors; Self Expandable Metallic Stents; Surveys and Questionnaires; Time Factors; Treatment Outcome; United States; Vascular Patency; Walking

Rupture-prone plaques in the coronary arteries, called ``vulnerable plaques'', are recognized as the key factor in acute myocardial infarction. Vulnerable plaques have a thin fibrous cap over a large fatty core and are highly susceptible to rupture. In general, this type of plaque rupture is mainly associated with stress concentrated on the fibrous cap. Fibrous cap stresses are counted among the most important factors in the plaque rupture process and must be taken into consideration when assessing the plaque vulnerability leading to heart attacks. The objective of this paper was to investigate the effects of nitinol stent deployment on the morphological changes of vulnerable plaques and then to propose a new stent design concept for effectively reducing fibrous cap stresses and the associated rupture risk. The deployment of a self-expanding nitinol stent was modeled, and the resulting stress distribution on the fibrous cap was investigated. The fibrous cap stresses were more uniformly distributed and the maximum stress was reduced by 13% when the crown number of the stent was increased. This study demonstrates an excellent approach to stent design that could effectively reduce the risk of a vulnerable plaque rupturing and causing a heart attack.

Topics: Alloys; Equipment Design; Humans; Myocardial Infarction; Plaque, Atherosclerotic; Stents; Stress, Mechanical

Regenerative cell-based therapies are associated with limited myocardial retention of delivered stem cells. The objective of this study is to develop an endocardial delivery system for enhanced cell retention.. Stem cell retention was simulated in silico using 1- and 3-dimensional models of tissue distortion and compliance associated with delivery. Needle designs, predicted to be optimal, were accordingly engineered using nitinol, a nickel and titanium alloy displaying shape memory and superelasticity. Biocompatibility was tested with human mesenchymal stem cells. Experimental validation was performed with species-matched cells directly delivered into Langendorff-perfused porcine hearts or administered percutaneously into the endocardium of infarcted pigs. Cell retention was quantified by flow cytometry and real-time quantitative polymerase chain reaction methodology. Models, computing optimal distribution of distortion calibrated to favor tissue compliance, predicted that a 75°-curved needle featuring small-to-large graded side holes would ensure the highest cell retention profile. In isolated hearts, the nitinol curved needle catheter (C-Cath) design ensured 3-fold superior stem cell retention compared with a standard needle. In the setting of chronic infarction, percutaneous delivery of stem cells with C-Cath yielded a 37.7±7.1% versus 10.0±2.8% retention achieved with a traditional needle without effect on biocompatibility or safety.. Modeling-guided development of a nitinol-based curved needle delivery system with incremental side holes achieved enhanced myocardial stem cell retention.

Topics: Alloys; Animals; Cell- and Tissue-Based Therapy; Computer Simulation; Disease Models, Animal; Drug Delivery Systems; Endocardium; Equipment Design; Male; Myocardial Infarction; Needles; Stem Cell Transplantation; Stem Cells; Swine; Treatment Outcome

In the setting of ST-elevation myocardial infarction (STEMI), epicardial vasoconstriction and thrombus load may lead to stent undersizing and malapposition after primary percutaneous coronary intervention (PPCI), which can both be responsible for stent thrombosis or restenosis. Aggressive stent deployment can, on the other hand, cause distal embolisation and the no-reflow phenomenon. The purpose of our study was to evaluate the safety and feasibility of a novel self-expanding stent by assessing the clinical, angiographic and intravascular outcomes after stent deployment at three days and at six months follow-up.. This prospective, multicentre, non-randomised study enrolled 25 STEMI patients undergoing PPCI; a nitinol, self-expanding, coronary stent (STENTYS® stent; STENTYS, Paris, France) was used in all patients. Angiography and intravascular ultrasound (IVUS) or optical coherence tomography (OCT) were performed immediately after stent deployment, after three days and at six months. Primary safety endpoints were mortality, reinfarction, stent thrombosis and stroke at discharge and at six months. The primary feasibility endpoints were technical, device and procedural success, and stent apposition at three days and six months. Secondary endpoints included distal embolisation, binary restenosis, ischaemia-driven target lesion revascularisation (TLR) and late lumen loss (LLL). There were no adverse events at discharge or at six months. Technical, device and procedural success were 100%, 96% and 96%, respectively. IVUS showed a significant vasodilatation distal to the culprit lesion at three-day follow-up (+19%), with a concordant expansion of the implanted stent (+18%), p≤0.001 for both values. One case of distal embolisation was reported. There were no cases of late stent malapposition at six months. In-stent and in-segment LLL were 0.71±0.71 mm and 0.58±0.61 mm. Binary restenosis was 25%, ischaemia-driven TLR was 12%.. This study shows that the use of the STENTYS® self-expanding stent is safe and feasible in STEMI patients. Three days after the procedure, the stent expanded to the same extent as the epicardial vasodilatation and appeared completely apposed to the vessel wall. This could be of benefit in preventing stent thrombosis in the setting of STEMI.

Topics: Adult; Aged; Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Embolism; Europe; Feasibility Studies; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Prosthesis Design; Recurrence; Stents; Thrombosis; Time Factors; Tomography, Optical Coherence; Treatment Outcome; Ultrasonography, Interventional

We investigated the safety, feasibility and efficacy of the Occlutech devices for patent foramen ovale (PFO) and atrial septal defect (ASD) closure in a prospective trial.. The retention discs of the PFO device (23 x 25 mm, 27 x 30 mm) are connected by a 3 mm waist in the center with only one right atrial side central pin. The left atrial disc is produced either with a single or double flat layer, which allows a significant reduction of meshwork material. The ASD occluder (6-40 mm, 3 mm increments) has only one central pin on the right atrial side. Indications for closure included cryptogenic stroke with evidence of a PFO on transesophageal echocardiography (TEE) or an ASD II. The devices were implanted in 29 patients with PFO and in 12 patients with ASD II (fluoroscopy and TEE). An echocardiographic follow-up examination was performed after 1, 2 and 6 months.. The devices were successfully implanted in all 41 patients. There were no periprocedural complications. One patient with ASD II died of recurrent myocardial infarction without evidence of cardioembolic origin. TEE studies showed a residual shunt in 11.2% after 60 days in patients with PFO and a left-to-right shunt in 9.1% of the remaining patients with ASD II. After 180 days only 1 patient with PFO had a right-to-left shunt (3.7%). A residual shunt in the patients with ASD was not observed.. The novel Occlutech devices appear to be safe, feasible and effective for PFO and ASD closure, with a significant reduction of the meshwork and absence of left atrial central pin.

Topics: Adult; Aged; Alloys; Animals; Echocardiography; Echocardiography, Transesophageal; Equipment Failure Analysis; Equipment Safety; Feasibility Studies; Female; Foramen Ovale, Patent; Foreign-Body Reaction; Heart Septal Defects, Atrial; Humans; Male; Middle Aged; Myocardial Infarction; Postoperative Complications; Prosthesis Design; Septal Occluder Device; Swine; Swine, Miniature

Topics: Aged; Alloys; Echocardiography; Equipment Failure Analysis; Equipment Safety; Female; Foramen Ovale, Patent; Foreign-Body Reaction; Heart Septal Defects, Atrial; Humans; Male; Middle Aged; Myocardial Infarction; Postoperative Complications; Prosthesis Design; Septal Occluder Device