View clinical trials related to Atherosclerosis.
Filter by:Instantaneous wave-free ratio (iFR™) is a novel non-hyperaemic index of the functional significance of a coronary stenosis. Previous studies have shown variable levels of correlation with the established hyperaemic index FFR. In addition it has been proposed that iFR™ has superior diagnostic accuracy when compared to mean whole cardiac cycle Pd/Pa which can also be used to predict FFR. We plan to undertake a prospective clinical study in consecutive patients already undergoing FFR assessment in the cardiac catheterisation laboratory to compare the ability of iFR™ and Pd/Pa (both measured using the proprietary Volcano system) to predict FFR. We will explore the level of misclassification of flow limiting disease that results from use of iFR™ and resting Pd/Pa employed using either binary cut-off algorithms or in a hybrid decision making protocol. We plan to analyse 260 vessels over a 18 month period. Hyperaemia will be induced by intravenous adenosine (140 ug/kg/min) administered wherever possible via an antecubital vein. Intra-coronary nitrates will also be given in line with the standard care procedure for FFR measurement. Final clinical decisions following coronary physiology will be based on steady state FFR.
Current oral anti-coagulation for atrial fibrillation is most commonly performed with warfarin. Warfarin is a vitamin K antagonist that has been shown in non-randomized trials to increase vascular calcification. Increased vascular calcification has been tied to increased cardiovascular events (CVE). This study will randomize patients currently taking warfarin to either continue on warfarin or be switched to rivaroxaban. Rivaroxaban is an oral anti-coagulant that works by inhibiting Factor Xa, and has no interaction with vitamin K. This study is a randomized, open label study that will randomize 120 patients and have them undergo blood tests and a calcium scan at baseline, and again after 12 months. Patients will be seen quarterly for examinations, safety checks and supply of rivaroxaban, as well as follow up INR testing for warfarin.
Stent delivery failure occurs in 4% of all percutaneous coronary interventions (PCI) and >90% of these failures are due to vessel tortuosity and/or calcification. The XLIMUS eluting coronary stent (CARDIONOVUM GmbH, Bonn, Germany) is a new type of endovascular prostheses characterised by better mechanical properties than traditional DES. This is a prospective, non-randomized, single-center pilot study, aiming to evaluate the performance of the XLIMUS DES in severely complex coronary lesions in real-world clinical practice.
The overall objective of the current proposal is to strengthen the putative link between FFA induced insulin resistance and atherosclerotic vascular disease (ASVD). To this end, the investigators will test the following hypotheses: 1) that FFA induced activation of protein kinase C βII (PKC β II) and δ and other serine kinases such as IκB kinase (IKK) in human muscle is associated with a decrease in insulin stimulated tyrosine phosphorylation of the insulin receptor substrate-1 (IRS-1) and of IRS-1 associated phosphatidylinositol 3 (PI3) kinase; 2) that these changes precede the development of insulin resistance; 3) that the decrease in IκB-α results in activation of nuclear factor κB (NFκB) and the expression of adhesion molecules and cytokines; 4) that PKC and IKK are involved in producing insulin resistance and activation of the IκB/ NFκB pathway and lastly 5) that the same mechanisms operative in healthy volunteers are also operative in patients with T2DM.The investigators will test these hypotheses in normal (current) and diabetic volunteers (previously completed) . Euglycemic-hyperinsulinemic clamps will be performed with and without co-infusion of lipid plus heparin (to raise FFAs) and by obtaining serial muscle and fat biopsies and blood samples will be obtained for measurement of substrates, hormones, enzymes and metabolites.
The purpose of the Patient and Provider Assessment of Lipid Management Registry (PALM) is to gain a better understanding of physicians' cholesterol medication prescribing practices, patient and physician attitudes and beliefs related to cholesterol management, and current utilization of cholesterol-lowering therapies given the new ACC/AHA guideline recommendations. The PALM Registry hopes to allow for the design of ways to improve cholesterol management and decrease the burden of cardiovascular disease (CVD) in the US.
The purpose of this study was to investigate whether the no-touch saphenous vein grafts that were used in coronary artery bypass surgery between 2003-2008 had a patency rate comparable to the left internal thoracic artery when the vein grafts were anatomised to the left anterior descending artery.
The purpose of this study is: 1. To examine the association between stable and unstable coronary artery disease (CAD) with markers of DNA damage and repair, 2. To examine the association between plaque morphology as assessed by frequency-domain optical coherence tomography (FD-OCT) and markers of DNA damage and repair in order to identify potential markers of plaque instability, 3. To examine the association between markers of DNA damage and repair and major adverse cardiovascular events defined as death, MI and unplanned percutaneous or surgical revascularization,
Atherosclerosis may initiate early in life and takes years to progress. This contrasts to the abrupt coronary or cerebrovascular events occurring following the transition from a stable to an unstable atherosclerotic plaque. The causes of this discontinuity of the disease are complex and probably multiple. There is increasing evidence that, besides inflammation, neovascularisation of atherosclerotic plaques and intra-plaque hemorrhages play an important role in plaque instability ending-up frequently in acute thrombotic occlusion or distal embolisation of athero-thrombotic material associated with heart attack or stroke. Contrast-enhanced Ultrasound, is a bed-side non-invasive technique, which allows to enhance microvascular structures and to visualize the adventitia and intraplaque vascularization. Dynamic contrast-enhanced plaque MRI (DCE-MRI) which has also been evaluated for in vivo detection and quantification of plaque neovascularity. Together with the presence of a large lipid-rich core, thin fibrous cap, positive remodeling and active inflammatory infiltrate, plaque neovascularisation is considered a valid marker of high-risk (or vulnerable) plaque as demonstrated in histopathological studies using microvessel density. Aim of the study is to assess and validate the value of contrast enhanced ultrasound (CEUS), a bed-side technique, in detecting plaque neovascularisation and compare it with the quantitative assessment by DCE-MRI in carotis atherosclerosis. A group of 30 patients with asymptomatic carotid atherosclerosis (> 50% stenosis on Doppler ultrasound) will undergo Carotid Duplex ultrasounds and CEUS. High-resolution plaque MRI and DCE-MRI will be performed in the same patients and will be analyzed by two separate operators blinded to the results of the CEUS in order to detect the efficacy of CEUS when compared with in vivo DCE-MRI, as the standard of reference.
The purpose of this research study is to determine if Intravascular Ultrasound (IVUS) grayscale and VH (Virtual Histology)-IVUS pre-stenting can assess more accurately the location, amount, and type of a blockage than angiogram alone. Additionally, this study is to determine if IVUS grayscale and VH-IVUS guidance will result in improved acute and long term procedural outcome vs. bifurcation stenting with only angiographic guidance in native coronary arteries.
HIV-infected individuals on antiretroviral therapy (ART) are at increased risk for cardiovascular disease (CVD), likely due to chronically increased inflammation. Low-dose methotrexate (LDMTX) may reduce CVD risk in people with rheumatoid arthritis, who like those with HIV, have increased levels of inflammation. The NHLBI is funding a clinical trial targeting the excess inflammation in HIV. That "Parent Study" is a randomized, double-blind, placebo-controlled trial (NCT01949116) that will assess whether 24-week treatment with LDMTX: i) is safe, ii) reduces circulating inflammatory biomarkers and levels of immune cell activation and iii) improves brachial artery reactivity. However, neither the biomarkers nor endothelial function tests measured as part of the parent study will report on atherosclerotic inflammation, (the desired pathobiological target of LDMTX therapy in HIV). As such, the direct evaluation of arterial inflammation would substantially enhance the scientific value of the trial. In this imaging sub-study, the overall goal is to determine if treating virologically suppressed, HIV-infected individuals with LDMTX will reduce inflammation within the arterial wall. This fully integrated ancillary study would, in a subset of patients enrolled in the parent trial: (i) assess the impact of LDMTX on arterial inflammation, (ii) evaluate mechanisms responsible for arterial inflammation in HIV and iii) explore mechanisms responsible for actions of LDMTX on the artery wall. Accordingly, the proposed study would provide unique and highly complementary information that would greatly increase the knowledge and mechanistic insights gained from Parent Study. The ancillary study has two specific aims1) To determine the impact of anti-inflammatory treatment with LDMTX on arterial inflammation, as assessed by FDG-PET/CT imaging, in virally suppressed HIV-infected individuals., and 2) To evaluate the cellular and biochemical basis of the effect of LDMTX therapy on arterial inflammation in HIV.