View clinical trials related to Myocardial Ischemia.
Filter by:CORONARY ARTERY DISEASE AND THE BENEFIT OF BYPASSES Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally. In industrialized countries, coronary artery disease (CAD) is the leading cause of death, consequence of myocardial infarction (MI). Artificial - or natural - bypasses exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. In patients with chronic CAD, sufficient coronary collaterals have been shown to confer a significant benefits in terms of overall mortality and cardiovascular events. EXTRACARDIAC-TO-CORONARY COLLATERAL SUPPLY Commonly, coronary collaterals are implicitly understood to exist between coronary artery branches. However, the structural existence of coronary collaterals with an extracardiac connection has been confirmed by anatomical investigations. Pathophysiologically and with regard to a potential for arteriogenic stimulation, the connections from the internal mammary arteries, are of special interest. In a recently published work the investigators have investigated the effect of temporary balloon occlusion of the distal IMA on coronary collateral function. There were equivocal findings for the left circumflex coronary artery: CFI was increased by ipsilateral IMA occlusion, but the level of myocardial ischemia was unchanged. MYOCARDIAL STEAL VIA INTERNAL MAMMARY ARTERIES In the investigators' previous study, the coronary occlusion with simultaneous distal IMA occlusion was always performed first as a conservative measure against false-positive detection of internal-mammary-to-coronary artery connections. Repetitive coronary occlusions per se result in higher collateral flow by collateral recruitment and reduced ischemia by ischemic preconditioning and augmented collateral function. Conversely, the sensitivity of the employed method was reduced and might have contributed to the equivocal findings in case of the left circumflex artery. Moreover, the hypothesize d mechanism of localized pressure augmentation was not investigated. This study aims to further characterize the prevalence and function of natural ipsilateral IMA-to-coronary connections, as well as to investigate the hemodynamic mechanisms of coronary collateral function augmentation by distal IMA occlusion. In the investigators' last study, the increased coronary collateral function in response to manipulation of a potential coronary collateral donor (in this case, the IMA) was taken as indirect evidence for the existence of IMA-to-coronary-artery connections. Thus, the employed distal IMA occlusion served as a positive stimulus. Conceptually, additional evaluation with a negative stimulus could heighten the discriminatory power of the investigation. This could be in the form of a hyperemic stimulus affecting the collateral donor, ie in analogy to myocardial or coronary steal (ie, a reduction in coronary collateral supply to a collateral recipient).
The principal hypothesis of this study is that two different maintenance regimens of ticagrelor are safe, tolerable and associated with significant inhibition of erythrocyte adenosine reuptake compared to clopidogrel in patients undergoing elective Percutaneous Coronary Intervention (PCI) for stable Coronary artery disease (CAD).
The objective of this study is to determine the rate of radial artery occlusion and vascular access site complications following transradial angiogram using a new Terumo (Tokyo, Japan) Glidesheath Slender, in comparison with the currently used 6 French (6 Fr.) radial sheath.
Using a randomized clinical trial with 3 groups, the investigators will conduct a head-to-head evaluation of two different theoretically-based interventions, SystemCHANGE and CHANGE+, as compared to Usual Care to improve the adoption and maintenance of exercise in older cardiac patients. SystemCHANGE, a novel intervention that focuses on environmental change uses System Improvement strategies to increase exercise, will be compared to CHANGE+ (an intervention based contemporary cognitive behavioral strategies). Study questions are: (1) Is there a difference between SystemCHANGE, CHANGE+ and Usual Care in exercise adoption when controlling for covariates (age, race, functional capacity, body fat, co-morbidity, muscle or joint pain, exercise experience, home and neighborhood environment, and depression), for individuals following a cardiac rehabilitation program (CRP)? (2) Is there a difference between SystemCHANGE, CHANGE+, and Usual Care in exercise maintenance when controlling for covariates? (3) Do system changes, social support for exercise, problem-solving skills, motivation, health beliefs, and exercise self-efficacy mediate the effects of SystemCHANGE, CHANGE+, or Usual Care on exercise adoption? (4) Do system changes, social support for exercise, problem-solving skills, motivation, health beliefs, and exercise self-efficacy mediate the effects of SystemCHANGE, CHANGE+ and CHANGE+ interventions in terms of health care spending, labor force participation and earnings, and household productivity? Older persons (N=420) recovering from cardiac events will be randomly assigned to the three groups. Measures of exercise adoption and maintenance (# of metabolic equivalents {METS} expended, and whether or not a subject remains exercising) will be taken for 1 year after completion of a CRP using heart rate wristwatch monitors, exercise diaries, and 7-Day Recall Survey. The effect of covariates also will be assessed. Mechanisms by which the interventions achieve their effects will be determined. Multivariate analyses will examine and compare the effects of the interventions over time. A cost-effectiveness analysis also will be conducted.
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.
Background: About 5% of patients with acute coronary syndrome (ACS) have had previously ischemic stroke (IS) or transitory ischemic attack (TIA). This is a high-risk population, with a high incidence of ischemic events, and also of bleeding events. While the high ischemic risk in this population is attributed to a higher prevalence of cardiovascular risk factors, their predisposition to bleeding events is not well understood. Hypothesis: The increased bleeding risk in ACS patients with history of cerebrovascular event may be justified by a low platelet activity. Methods: Unicentric, prospective, case-control study, which included approximately 100 post-ACS patients with history of IS/TIA previously to the acute coronary event (Case Group) and 100 patients without IS/TIA (Control group). The groups were matched for gender, age, and ACS type and year of occurrence. All patients were taking aspirin, and the main exclusion criteria were use of dual antiplatelet therapy, previous hemorrhagic stroke, severe renal dysfunction, thrombocytopenia or coagulopathy. Main analysis: Platelet aggregation was evaluated by 6 methods: VerifyNow Aspirin®, VerifyNow P2Y12®, PFA 100®, thrombelastography (ReoRox®), light transmission aggregometry with ADP (LTA ADP) and epinephrine (LTA EPI) as agonists. Additional analysis: genetic, HDL transport and inflammatory evaliation
A single-centre double-blind placebo-controlled crossover randomised controlled trial to determine the physiological basis of glucagon-like peptide-1 receptor activation on exercise haemodynamics, as manifest through specific electrophysiological parameters measured by serial exercise stress testing, in those patients with reversible myocardial ischaemia and obstructive coronary artery disease confirmed by a baseline exercise test and coronary angiography respectively.
Ischemia reperfusion injury may be attenuated by HO-1 induction. Our previous data confirmed strong HO-1 induction in peripheral blood cells following heme arginate infusion in healthy humans. Furthermore, we could demonstrate the amelioration of experimental ischemia reperfusion injury in the calf musculature by heme arginate in healthy subjects as measured by functional MRI. Therefore, we propose that HO-1 induction in the human heart may be a suitable target to mitigate cardiac ischemia-reperfusion injury. The HO-1 induction will be assessed in a clinical trial by myocardial biopsy prior to and after aortic cross-clamping in subjects with or without preceding heme arginate treatment in two different dosages. The HO-1 expression will also be measured in the clinical trials in peripheral blood mononuclear cells. As additional outcome, levels of myoglobin, creatine-kinase and troponin T and reactive oxygen species will be measured in plasma according to standard laboratory procedures.
Coronary heart disease (CHD) pose a serious health threat to population. PCI using drug eluting stents (DES), as a well-proved and booming measure in CHD management, is invasive and of high cost, however the knowledge about the real-life DES use and the efficacy and safety in China is limited. By consecutively recruiting first-ever PCI patients in 30 geographically representative highest-rank hospitals, this study will examine the prognosis in groups with different brands of DES, and various real-life factors, that may affect patients recovery after the procedure. Evidence for clinical practice and health resource allocation will be established based on the findings, to improve patients outcomes in future finally.
Psoriasis is an inflammatory disease involving the skin, the joints and the vascular compartment. The mechanisms linking inflammation in the skin and joints and in the vascular walls are poorly understood. One hypothesis for the increase in vascular inflammation observed in patients with psoriasis involves circulating pro-inflammatory cytokines. Patients with psoriasis have an increase in serum levels of tumor necrosis factor alpha (TNF-alpha), Interleukin-17 (IL-17), IL-22, IL-6 as well as a the chemokine S100A913. It is possible that one of those cytokines/chemokine induces vascular inflammation in the vascular compartment. The purpose of this cross sectional retrospective study is to highlight the correlation between vascular wall inflammation using 18F-2-fluoro-2-deoxy-D-glucose - Positron Emission Tomography (FDG-PET) fluorodeoxyglucose technology and pro-inflammatory cytokines/chemokine.