Active clinical trials for "Myocardial Ischemia"

About 35% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. Chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. The responsible mechanisms for increased rate of ischemic events in this population are not completely elucidated. Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. This population is often excluded or underrepresented in large clinical trials, and the indication of antiplatelet therapy is often extrapolated from studies in patients with preserved renal function. In recent meta-analysis, Palmer et al. sought to evaluate the benefits and risks of antiplatelet agents in patients with CKD and concluded that in patients with ACS or scheduled for angioplasty already taking aspirin, the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization. In the PLATO trial, ticagrelor (a new reversible inhibitor of P2Y12 receptor with faster onset of action and greater platelet inhibition) was compared to clopidogrel in patients with high risk ACS and was associated to a 16% risk reduction on the occurrence of death from vascular causes, myocardial infarction, or stroke. In a pre-specified sub-analysis, data from patients with CKD were compared to those obtained from the population with normal renal function and suggests that the benefit of ticagrelor may be even greater in patients with CKD. Two hypotheses were considered to explain these results: Greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk; Pleiotropic effects of ticagrelor besides inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine. This could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction. This project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.

The mainstay for treatment for acute coronary syndrome (ACS) focusses on re-establishing and maintaining the patency of vessels following coronary plaque disruption, through the use of anti-platelets and anticoagulants. Despite advances in management ACS still carries a high risk of morbidity and mortality, thus future management is likely to target other pathways. Recent studies indicate that CD4+ T cells, and more specifically Treg cells, are important for the control of post-ischemic immune responses and the promotion of myocardial healing. The investigators therefore hypothesise that expansion of Treg cells in patients with ACS dampens the activation of the immune response and promotes both plaque and myocardial healing. The investigators hypothesise that this can be achieved through subcutaneous administration of low doses of interleukin-2 (IL-2). IL-2 supplementation appears to be an attractive therapeutic option playing a key role in Treg cell development, expansion, survival and suppressive function.

The objective of this study is to investigate the value of employing the aortic no-touch off-pump coronary artery bypass technique and the practice of carbon dioxide surgical field flooding for the prevention of type 1 and 2 neurological injuries following surgical coronary revascularization.

Angina and heart attacks are caused by narrowings in the coronary arteries (blood vessels) supplying the heart. These narrowings can be opened using a balloon and stent (angioplasty). Traditionally, stents are constructed from metal and are permanent. However, newer stents are being constructed from carbohydrate polymers (scaffolds), which allow them to reabsorb over time leaving no permanent implant. New data has suggested that these scaffolds appear to reduce recurrent angina and may alter the blood flow down the artery. However, it is not known whether this is due to the scaffolds themselves or the way the scaffolds are inserted. In this study we hope to measure the blood flow to the heart and assess changes in that flow during stent and scaffold insertion. It is also important to know whether these effects are durable and thus, a cohort of patients will return at 3-months to be restudied. These data are important to help us understand why blood flow is affected by stent/scaffold selection or device implantation technique and whether this results in better long-term outcomes.

The present study aimed to investigated the effect of Enhanced External Counterpulsation (EECP) on vascular hemodynamics and atherosclerosis, and the underlying shear stress related mechanisms

Thus, the purpose of the present study was to evaluate the effects of continuos exercise training (CET) and interval exercise trainining (IET) on oxygen uptake efficiency slope (OUES) in patients with coronary artery disease.

Anticoagulation with heparin is indicated in several situations, such as acute coronary disease (in combination with antiplatelet therapy) for the prevention and treatment of venous thromboembolism and situations with high risk of thromboembolism. Recently, the latest trials on anticoagulation for stroke prevention on atrial fibrillation have shown an increased risk for acute mycardial infarction on patients submitted to new oral anticoagulants, such as dabigatran. The mechanism is still unclear, however, in this context, some previous studies about interaction between anticoagulants ( mainly heparin) and platelet aggregation have shown conflicting results: while some suggest an inhibitory effect of heparin on platelet function, others suggest that heparin could promote an increase in platelet activation. The present study aims to assess the effects of the LMWH Enoxaparin and direct thrombin inhibitor, Dabigatran, on platelet aggregation, studied and compared by different methods in patients with chronic coronary artery disease (CAD).

The objective of this study is to assess the safety and efficacy of the Orsiro Sirolimus Eluting Coronary Stent System in the treatment of subjects with up to three native de novo or restenotic (standard PTCA only) coronary artery lesions compared to the Xience coronary stent system.

Cardiovascular diseases remain the number one cause of death globally, primarily consequence of myocardial infarction. Although widely used in stable coronary artery disease (CAD), percutaneous coronary intervention (PCI) has not been shown to reduce the incidence of myocardial infarction or death. In contrast, coronary artery bypass grafting (CABG) significantly reduces rates of death and myocardial infarction compared to PCI, but at a higher rate of stroke. Similarly, coronary collaterals 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. Sufficient coronary collaterals have been shown to confer a significant benefit in terms of overall mortality and cardiovascular events. In this regard, the concept of augmenting coronary collateral function as an alternative treatment strategy to alter the course of CAD, as well as to control symptoms, is attractive. While a multitude of interventions has been shown to be effective in collateral growth promotion, so far, the effect of current interventions is only temporary, and therefore, repeated application is necessary to sustain the level of collaterals. The prevalent in vivo function of natural internal mammary arteries (IMA)-to-coronary artery bypasses and their anti-ischemic effect has been recently demonstrated by the investigators' research group. Levels of collateral function and myocardial ischemia were determined in a prospective, open-label clinical trial of permanent IMA device occlusion. In this study, coronary collateral function, has been shown to be augmented in the presence vs the absence of distal permanent ipsilateral IMA occlusion. These findings have been corroborated by the observed reduction in ischemia in the intracoronary ECG. Coronary functional changes observed in response to permanent distal IMA occlusion have so far, not been related to clinical outcome parameters. Therefore, a controlled, randomized, double-blind comparison of clinical efficacy between a group of patients receiving permanent IMA occlusion vs. a sham-procedure will be consequently performed. Since single antianginal agents have been demonstrated to increase exercise time in comparison to placebo, an improvement of the physical performance due to the increased blood flow by the permanent distal IMA occlusion is expected.

The study is to further exploring the optimal switching strategy by evaluating the pharmacodynamic responses as well as adverse events in patients with complexity of coronary artery disease managed by percutaneous coronary intervention (PCI). All participants will be divided into three groups and recieving ticagrelor 90mg plus aspirin 100mg at 12 hours after the last dose of clopidogrel; recieving ticagrelor 90mg plus aspirin 100mg at 24 hours after the last dose of clopidogrel; recieving ticagrelor 180mg plus aspirin 100mg at 24 hours after the last dose of clopidogrel.