Active clinical trials for "Constriction, Pathologic"

Ischaemic Heart Disease (IHD) is the worlds leading cause of death. IHD is often caused by a narrowing of the coronary arteries, which prevents blood from flowing to the heart muscle, causing pain and damage to the heart. If an individual has a myocardial infarction (MI), parts of the heart that are damaged cannot be repaired. Therefore, it is important to identify and treat the narrowing of the arteries before an MI occurs. At present there are 2 main methods of identifying narrowing of the arteries. The first is an invasive procedure, the other using a CT scan. Whilst both methods are effective, they entail risk. The invasive procedure can damage the coronary arteries, whilst the CT scan exposes patients to radiation and contrast, which can increase the risk of cancer and allergic reactions. Magnetic Resonance (MR) scanning is an alternative to these methods, but it has been limited in use in the past due, in part, to the high technical knowledge required to obtain images. In addition, there is a degree of subjectivity in the selection of the mid-diastolic rest period, potentially affecting consistency of results. This means it is difficult to use in a day-to-day hospital environment. However, recent technological developments using artificial intelligence mean that images can be acquired in a more automated and consistent fashion. This new scan has yet to be tested in a clinical trial. Therefore, the objective of the clinical study is to test this new scan to determine its efficacy. 230 patients at 5 sites at risk of coronary artery disease, who have been referred for invasive coronary angiography, will undergo both their angiography and the new MR scan. The MR scan will then be compared to CCTA for diagnostic accuracy and image quality. The investigators hypothesise that the new MR scan will have the same diagnostic accuracy as invasive coronary angiography, with no differences in interpretation of the images across the 5 different hospitals. If proven effective, this would demonstrate that MR scanning of the coronary arteries could prove a safe, clinically useful alternative to both CT scanning and invasive assessment of coronary artery narrowing. In addition, if there is no difference across different locations, it would demonstrate that these scans can be performed consistently, facilitating implementation on a healthcare-system wide basis.

This is a single-centre, prospective, observational cohort study focusing on of patients suffering severe aortic valve stenosis (AS) undergoing emergent transcatheter aortic valve implantation (TAVI). AS patients undergoing emergent TAVI always have complicated clinical situations. Therefore, the aims of the study are to collect the incidence and outcomes of emergent TAVI in patients with severe symptomatic AS, to assess the safety and effectiveness of emergency TAVI system for severe AS, and to describe a more practical evidence of emergency TAVI system in severe AS patients.

To evaluate the safety and effectiveness of Grency venous stent system in the treatment of iliac vein stenosis or occlusion.

Cervical stenosis may occur in up to 19% after conization. It is a cause of infertility and amenorrhea. This study will test a new device named DUDA Device ("Dispositivo Uterino para dilatar canal endocervical") placed just after the conization, in order to evaluate the safety, efficacy and quality of life.

First clinical experience on the ACURATE TF™ Transfemoral Aortic Bioprosthesis Implantation in Patients with Severe Aortic Stenosis to collect human data pertaining to the safety and performance of the device from three different cohorts

Prospective, randomized, multi-center study. Investigators will compare diagnostic yield of bile duct brushings, pediatric biopsy forceps biopsies and cholangioscopy-directed biopsies for obtaining diagnostic tissue from biliary strictures.

To assess the safety and feasibility of Transcatheter Aortic Valve Replacement (TAVR) with commercially available bioprostheses in patients with severe, symptomatic aortic stenosis (AS) who are low-risk (STS score ≤3%) for surgical aortic valve replacement (SAVR).

Atherosclerotic intracranial arterial stenosis (AICAS) corresponds to luminal narrowing of the major intracranial arteries. The prevalence of intracranial atherosclerotic stenosis accounts for 33% to 67% of stroke or transient ischemic attack (TIA) cases in China and other countries in Asia. AICAS is also highly associated with the risk of stroke recurrence. Possible mechanisms of cerebral infarction secondary to AICAS are likely linked with hemodynamic compromise distal to site of stenosis. Computed tomography perfusion (CTP) can be used to evaluate vasoreactivity and cerebrovascular reserve in patients with AICAS and predict future stroke. The parameters of CTP include ①cerebral blood flow(CBF),② cerebral blood volume(CBV) and ③mean transit time(MTT). Relative regional cerebral blood flow (rCBF) was evaluated as the percentage radioisotope counts in the region of interest (ROI) of the affected side against the corresponding ROI in the unaffected contralateral side. Statins can decrease the incidence of transient ischemic attack or ischemic stroke and improve stroke outcome. Few studies focus on the relationship between statins therapy and cerebral perfusion. Whether intensive rosuvastatin therapy compared with standard rosuvastatin therapy can improve hemodynamic situation and cerebral perfusion status in AICAS has not been illustrated. Based on those studies, the investigators hypothesized that intensive rosuvastatin may also improve the symptoms of AICAS not only through enhancing the stability of atherosclerotic plaques, but also its pleiotropic effects. So it can change the hemodynamic status around the plaque and increase cerebral flow in the downstream territory. So in this study the investigators try to analysis statin's impact on the hemodynamic changes as well as the downstream perfusion which is determined by CTP.

The purpose of this investigation is to collect data pertaining to the safety and performance of the ACURATE neo (TM) Aortic Bioprosthesis as implanted with the ACURATE neo (TM) TA Transapical Delivery System. This device is intended for treatment of subjects with severe aortic stenosis (AS) who have high risk for conventional aortic valve replacement (AVR) surgery. The ACURATE neo (TM) Aortic Bioprosthesis is intended for use via minimally-invasive transapical implantation in a well-defined population.

The purpose of this study is to evaluate safety of the study device and study device performance in patients presenting with severe aortic stenosis who are considered to be high risk for open surgical repair.