Active clinical trials for "Ischemia"

Surgical revascularization has proven its efficacy in term of morbidity and mortality in patients with multivessel coronary disease and poor left ventricular function. Nevertheless, if left ventricle is severely dilated, the improvement of global contractility and reduction of volumes is frequently absent after CABG even if substantial amount of myocardial viability is present. A value of > 140 ml for end systolic volume has been proposed as the cut off for the absence of recovery after revascularization. Recently, a reduction of cardiac volumes and improvement of regional and global contractility has been demonstrated in patients with advanced ischemic heart disease, severe dilation of left ventricle and poor candidates for revascularization after injection of stem cells in territories with residual viability.

We will compare three study groups receiving metoprolol, esmolol, or placebo. Level of anesthesia will be titrated to achieve the same range of BIS value in all groups. Our hypothesis is that the metoprolol and esmolol groups will require a lower level of anesthetic agent to achieve the targeted BIS range, compared to the placebo group. Our objective is to clarify if metoprolol, in a dose range used for perioperative cardiac protection, decreases anesthetic requirement.

The plasma concentration of high-density lipoprotein (HDL) can have anti-inflammatory, anti-oxidative and anti-thrombotic effects in addition to being able to remove cholesterol from peripheral tissues for secretion via the liver. The investigators hypothesise that elevation of plasma HDLs will reduce the inflammatory response following removal of unstable atherosclerotic plaques in the carotid artery. Such plaques can cause strokes and there is great benefit from early surgical removal, however such surgical procedures involve significant risks to the patient. The investigators propose infusing HDL into patients prior to removal of their unstable carotid plaque and measuring the changes in inflammatory responses in comparison to a similar placebo controlled group of patients.

This study will develop a model system that can be used to test medications for improving the ability of blood vessels to resist damage from diseases such as heart attack and stroke. The endothelium (inner layer of blood vessels) has built-in defense mechanisms to prevent blockage of blood flow, including the ability to stretch the vessel when it senses that blood flow is threatened. People with heart attack risk factors, such as high cholesterol, smoking and diabetes lose this ability. This study will develop a model that can measure the response to a lack of blood flow in the arm and be used to test new medicines to improve blood vessel health. Healthy males between 18 and 45 years of age who have no history of high blood pressure, high cholesterol, or diabetes and who have not smoked for at least 3 months before entering the study may be eligible to enroll. Participants lie in an adjustable reclining bed. Small catheters (tubes) are placed in the artery and vein of the forearm of the non-dominant arm at the inside of the elbow. Blood samples are collected from the tubes. Then, pressure cuffs are placed on both wrists and upper arms. A strain gauge (rubber band-type device) is placed around the forearms. The pressure cuffs are inflated and blood flows into the forearm, stretching the strain gauge at a rate proportional to the blood flow. Then, small doses of acetylcholine (a medicine that causes blood vessels to expand) are injected into the artery tube. After 20 minutes, blood flow to the non-dominant arm is blocked by inflating the pressure cuff. The subject squeezes a rubber ball about every 2 seconds for 90 seconds. The cuff is deflated after 15 minutes and blood samples are withdrawn from the tube in the vein. After 15 minutes, the procedure is repeated one more time.

The aim of this study is to study the safety and clinical efficacy of a novel Bioabsorbable Everolimus Eluting Bioresorbable Vascular Scaffold System (BVS, Abbott Vascular) in subjects with critical limb ischemia (CLI) following percutaneous transluminal angioplasty (PTA) of the tibial arteries.

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in industrialized countries despite advances in medical, interventional, and surgical revascularization therapies. In both, acute myocardial infarction (AMI) and chronic stable disease, standard therapeutic approaches may fail to restore tissue perfusion. Indeed, a substantial number of chronic CAD patients may not be amenable to standard revascularization therapies or percutaneous coronary intervention (PCI) may fail to restore coronary artery patency following an acute vessel occlusion (no-reflow phenomenon, microvascular obstruction). As a consequence, the long pursued strategy of augmenting myocardial perfusion by diverting blood from the coronary venous system to an ischemic region (venous retroperfusion) has again gained attention during recent years. Occlusion of the coronary sinus (CSO) was introduced to provide retroperfusion by transient augmentation of coronary venous pressure. Different devices using CSO have been invented and evaluated in animal models and small clinical trials, e.g. intermittent CSO (ICSO) and pressure-controlled intermittent CSO (PICSO) which seem to be effective for myocardial salvage. However, they are not yet employed in clinical routine, and importantly, the exact underlying mechanisms by which retroperfusion due to CSO may reduce myocardial ischemia are not yet understood. As "natural bypasses", coronary collaterals are anastomoses without an intervening capillary bed between portions of the same coronary artery or between different coronary arteries that represent an alternative source of blood supply to a myocardial area jeopardized by ischemia. Collaterals of the heart can be assessed quantitatively by coronary pressure measurements, which have become the gold standard (collateral flow index, CFI=[Poccl-CVP]/[Pao-CVP]). Theoretically, augmentation of coronary sinus pressure by CSO with an increase of venous backflow reaches the upstream collateral circulation, which in turn could lead to improved collateral flow from non-ischemic area(s) to an occluded, ischemic myocardial region by upstream flow diversion. On the other hand, when considering the formula to calculate pressure-derived CFI, it seems that augmentation of coronary back pressure would rather impair collateral flow (since central venous pressure is coronary sinus pressure). However, the regional effect of a global increase in coronary sinus pressure is unlikely to be as uniform as the above formula implies, i.e., the response is more pronounced in some than in other vascular territories. In experimental studies using dogs (with abundant collaterals), elevation of coronary sinus pressure caused an augmentation of regional myocardial blood flow in the collateralized area. In contrast, when ICSO was performed in pigs (which possess no preformed collaterals), it increased the pressure distal of an occluded LAD but did not improve blood flow or left ventricular function. In conclusion, experimental studies and pathophysiologic considerations suggest a necessary role of the collateral circulation for the beneficial effects of coronary sinus occlusion (CSO) observed in animals and humans; however, no clinical data are available so far on the effect of CSO on myocardial ischemia in the presence of varying collateral flow. Study hypotheses CSO decreases intra-coronary ECG ST-segment elevation during a 2-minute coronary occlusion. The decrease in occlusive intra-coronary ECG ST elevation during CSO is directly proportional to CFI. Coronary sinus oxygen saturation during coronary occlusion with CSO is directly proportional to CFI.

The purpose of this study is to compare 2 different cold storage solutions, used to preserve donor lungs for lung transplantation, and their effect on cytokine activation related to ischemic reperfusion injury. Primary endpoint is 30 day survival.

The most recent treatment for stroke rehabilitation is to combine physical training with other therapies to enhance or accelerate recovery.The hypothesis of this study is that remote ischemic conditioning (RIC) might have a beneficial effect on motor recovery of AIS

Through this study, the investigators are to prove that Cilostazol effectively prevent progression of intima-medial thickness in ischemic stroke patients with high risk of cerebral hemorrhage, along with no significant increase in the risk of occurrence of hemorrhagic side effects. The primary hypothesis of this study is; Cilostazol alone or with probucol will reduce the progression of intima-medial thickness compared to aspirin in the ischemic stroke patients with symptomatic or asymptomatic old cerebral hemorrhage.

This is a prospective, multi-center, randomized pilot study to document the effects of adventitial delivery of dexamethasone after atherectomy-based revascularizations of lesions below the knee in symptomatic patients with critical limb ischemia (CLI).