View clinical trials related to Myocardial Ischemia.
Filter by:The investigators are hoping to discover the cause of chest pain in patients with a normal coronary arteriogram. For patients with chest pain coronary angiography is the standard method by which the blood vessels of the heart can be visualized and any narrowing can be assessed. In some cases the investigators find totally normal coronary blood vessels or only minor disease. Such a finding is associated with an excellent long term prognosis. However, as a large proportion of patients with normal coronary arteries or mild coronary narrowings often continue to experience recurrent chest pains the investigators are interested in understanding the mechanisms responsible for this. The investigators hypothesise that in many cases, coronary artery spasms are responsible for the recurrent chest pains. These spasms usually respond to treatment with drugs known as vasodilators. The acetylcholine test (ACH-test) has been recommended by the European Society of Cardiology and the American College of Cardiology as a diagnostic test. This test can reveal whether the coronary blood vessels have a tendency to go into spasm. The investigators plan in this study to carry out the test in patients who have chest pains suggestive of coronary narrowings but are found to have normal or only mildly narrowed coronary arteries on angiography. A positive test -indicating a tendency for spasm- may help guiding therapy with vasodilators, which are often very effective to prevent coronary spasms. The investigators would also like to take blood samples during the test (before and after) from every patient to measure blood markers and see if there is a relation between these markers and the result of the ACH-test.
The purpose of this study is to determine if regadenoson is as safe and effective as adenosine when used in the cardiac catheterization lab during measurement of coronary flow reserve and fractional flow reserve. The study hypothesis is the assessment of Fractional Flow Reserve (FFR) in the catheterization lab can be performed with equivalent accuracy when hyperemia is induced with IV Regadenoson compared with IV Adenosine without compromising patient safety.
Reactive platelet hyperactivity following coronary artery bypass grafting (CABG) might lead to thrombotic complications and major ischemic cardiac events. The aim of this study is to evaluate the changes in platelet reactivity following CABG and to clarify a potentially beneficial effect of dual antiplatelet therapy in the group of patients with documented aspirin resistance following CABG. Platelet function will be assessed by multiple electrode aggregometry. Aortocoronary vein graft disease is comprised of three distinct but interrelated pathological processes: thrombosis, intimal hyperplasia and atherosclerosis. Early vein thrombosis is a major cause of vein graft attrition during the first month after CABG. Bypass patency can be improved with antiplatelet therapy which is the mainstay of treatment for patients after CABG. A beneficial effect of acetylsalicylic acid (ASA) on vein graft patency has been previously shown. Some patients experience thrombotic events despite continuous aspirin administration after CABG. The investigators hypothesized that low responsiveness to aspirin might be a precipitating factor for adverse thrombotic events following CABG. Low responsiveness to ASA, as assessed by platelet function tests, varies widely among patients. The etiology of postoperative platelet hyperactivity remains to be elucidated. In this study a new point-of-care assay named multiple electrode aggregometry (MEA) using a device called Multiplate analyzer (Dynabyte, Munich, Germany) has been utilized. It allows for rapid and standardized assessment of platelet function parameters. This is a prospective randomized trial. The aim of the study is to document whether introduction of dual antiplatelet therapy in patients with ASA resistance will lead to a lower incidence of major adverse cardiac events (MACE) at a six month follow up. The composite endpoint will include death, non-fatal myocardial infarction, stroke and cardiac rehospitalization. All patients will receive 300 mg of ASA starting 6 hours after surgery, provided that the chest tube output is minimal. On postoperative day 4 their platelet function will be assessed using the above mentioned MEA. The patients found to be aspirin resistant will then undergo the process of randomization. The first arm will include patients with ASA resistance in whom no additional antiaggregation will be administered. In the second arm the investigators will include patients who were randomized to receive 75 mg of clopidogrel in addition to the standard antiplatelet regimen of 300 mg of ASA. Platelet function monitoring allows for individual tailoring of the antiplatelet therapy. The goal of this study is to define whether this strategy will lead to improved patient outcomes. Both major and minor bleeding complications will be strictly monitored and reported.
Elective percutaneous coronary intervention (PCI) is associated with troponin release in approximately one third of cases. Myocardial necrosis may result from downstream embolization of atheromatous material, coronary side-branch occlusion and may involve ischemia/reperfusion injury. The investigators hypothesized that a single remote ischemic preconditioning cycle would reduce peri-procedural troponin release.
The present prospective, multicenter study will therefore be performed with the primary objective of establishing the correlation between fractional flow reserve (FFR) and intravascular ultrasound with virtual histology (VH-IVUS)-derived parameters in angiographically intermediate coronary lesions. The current study will also examine the relative prognostic utility of FFR and VH-IVUS as a tool to defer percutaneous coronary intervention (PCI), by assessing the long-term rate (up to 3 years) of lesion-related clinical events if deferred by FFR vs. VH-IVUS versus not deferred PCI.
This is a prospective, multi-center registry to evaluate safety and effectiveness of the Everolimus Drug Eluting Stent for treatment coronary revascularization in Chinese patients with long lesion, small vessel or multi-vessel diseases.
This is a multi-center, prospective registry of patients with intermediate coronary lesions defined as a stenosis of 40-80% by angiography. Approximately 300 patients will be enrolled into the study at sites in the United States and Europe. There will be no follow up beyond hospital discharge in this study. A sub-group of 30 patients will undergo Adenosine MRI. The investigators hypothesize that Intravascular Ultrasound Radiofrequency (IVUS RF) anatomical criteria, such as minimal luminal area, plaque burden and virtual histology plaque type, can predict physiological ischemia by Fractional Flow Reserve (FFR).
The objective of this study is the assessment of the performance, safety and efficacy of the ProNOVA XR Polymer Free Drug Eluting Stent System in the treatment of patients with de novo native coronary artery lesions.
This study is for people who have a SPECT scan (nuclear imaging of the blood flow to the heart muscle) ordered by their medical doctors. As part of the SPECT scan, they will have been given a drug called regadenoson to widen and expand the blood vessels bringing blood to the heart muscle. The SPECT pictures of the heart are taken about an hour after the regadenoson is put into an arm vein through an IV. In this study, additional echo pictures will be taken and compared to the SPECT pictures. The aim of the study is to see if the echo pictures work as well as SPECT to measure the blood flow to the heart muscle.
The objective of the study is To verify the safety and efficacy of the MDT-4107 Drug-Eluting Coronary Stent in the treatment of de novo lesions in native coronary arteries with a reference vessel diameter (RVD) that allows the use of 2.25mm diameter stents.