Active clinical trials for "Coronary Artery Disease"

Cardiovascular (CV) disease is the leading cause of death in Canada. Fifty percent of all Tc-99m used in nuclear medicine is for the diagnosis of coronary artery disease (CAD) with SPECT myocardial perfusion imaging (MPI). The reduced supply of Tc-99m requires other tracers to be investigated. Tl-201 SPECT is available but generally accepted to be inferior to Tc-99m. Rubidium (Rb-82), a nonreactor produced tracer, is believed to have superior accuracy compared to Tc-99m and Tl-201 SPECT, with 5-20 times lower radiation dose. In the U.S. Rb-82 generators have been FDA-approved since 1989 and are used increasingly for CAD diagnosis, but are still considered investigational in Canada. Objectives: To demonstrate that Rb-82 PET MPI is i) an accurate, cost-effective alternative to Tc-99m; ii) superior to Tl-201; iii) can be implemented in multiple Canadian centres for the diagnosis and management of CAD. Short term clinical outcomes of Rb-82 will be evaluated and compared to Tc-99m and Tl-201 SPECT MPI across Canadian imaging centres. Plan: Rb-ARMI is an innovative multidisciplinary, multi-centre imaging research initiative that builds on existing collaborative networks and Canadian industry partnership (DRAXIMAGE). Rb PET will be implemented, standardized and validated in 4 overlapping phases over 2 years, at 10 Canadian Centres. Impact: This project meets the expected goal to "lead to clinical trial applications and clinical validation studies which compare novel radiolabeled probes with those in current practice", and to "bring a new radiopharmaceutical to the clinic" within a short time frame. Increased use of Rb-82 PET MPI has the potential to reduce the demand for Tc-99m by 10-40%, effectively increasing the available supply for other procedures, and improving the standard of care for many Canadians at risk of heart disease.

Thrombin is the most potent activator of platelets, and platelet activation is a hallmark of thrombosis. Coronary artery disease (CAD) is the major cause of mortality and morbidity in the United States and other industrialized countries, and thrombotic sequelae are the key cause of death in diabetes. The accumulation of thrombin at sites of vascular injury provides one of the major mechanisms of recruiting platelets into a hemostatic plug. Thrombin works by activation of the G protein-coupled protease activated receptors PAR1 and PAR4 on human platelets to initiate signaling cascades leading to increases in [Ca]i, secretion of autocrine activators, trafficking of adhesion molecules to the plasma membrane, and shape change, which all promote platelet aggregation. The thrombin receptors work in a progressive manner, with PAR1 activated at low thrombin concentrations, and PAR4 recruited at higher thrombin concentrations. As direct thrombin inhibitors become widely used in clinical practice, it is important to assess their effects on vascular function. Our hypothesis is that PAR1 and PAR4 do not signal through the same G protein pathways, and that PAR4 is not a strong platelet agonist. To investigate this hypothesis, the investigators will study the G protein pathways downstream of PAR4, and assess ex-vivo platelet responsiveness to thrombin, PAR1, and PAR4 agonist peptides, both in normal human subjects, and along the stages of pathology, from patients with stable angina as well as unstable angina who are undergoing angioplasty. Similarly, the investigators will examine platelet function in patients with metabolic syndrome as well as diabetes, along the continuum from insulin resistance to full-blown disease. These studies will provide deeper insight into the G protein pathways used by PARs. They will elucidate the contribution of PAR receptors to normal platelet function as well as the abnormal platelet activation in thrombotic states. The long term goal is to understand the implications for PAR receptors as therapeutic targets for anti-platelet therapies that may carry less bleeding risk.

This study will be co-ordinated by Dr Hector Chinoy, Dr Robert G Cooper (Salford Royal NHS Foundation Trust / The University of Manchester) and Dr Ian N Bruce (Central Manchester University Hospitals NHS Foundation Trust/ The University of Manchester). An initial pilot study will be completed, to establish proof of concept of the study and to examine whether trends may observed of differences between cases and controls. Twenty five prevalent UK Caucasian adult IIM cases, confirmed by internationally accepted criteria, will be recruited via the Adult Onset Myositis clinic, Salford Royal NHS Foundation Trust. Age, gender and race-matched controls will be recruited on a 'best friend' system. At the Wellcome Trust Clinical Research Facility (WTCRF), The University of Manchester, facilities are already available for B-mode ultrasound CIMT measurement, Endo-PAT, lean body mass measurement and contrast echocardiography. Cases and controls will have their cardiovascular risk factors assessed using a standardised questionnaire and blood tests. Further tests performed will include blood pressure, electrocardiogram, lean body mass, B-mode ultrasound CIMT measurement and Endo-PAT. IIM cases will have additional blood tests and a clinical assessment to assess their disease status, and contrast echocardiography. As part of a linked study, subjects (but not controls) will also have Gd-DTPA-MRI of the heart performed.

The real impact of cardiac surgery and coronary angioplasty remains to be clarified and, where appropriate, the influencing factors in a way beneficial or deleterious remain to be identified. The identification of such factors could make even faster screening, prevention and therefore open therapeutic prospects for those patients. The objective of the study is to constitute a prospective cohort to assess the occurrence of cognitive decline after cardiac surgery (200 patients) and coronary angioplasty (200 patients) using the scale Dementia rating scale (DRS) of Mattis. In addition, the investigators will identify factors that influence positively or negatively, the occurrence of such a cognitive decline. The study based on a systematic monitoring of clinical, biological, imaging and pharmacological factors and, to correlate the respective influence of these factors on the incidence of cognitive decline.

Serum NGAL has been described as a biomarker of neutrophil activation and an inflammatory marker which correlates to obesity and its metabolic complications. Since neutrophil activation has been implicated in the pathogenesis of coronary artery disease, the investigators hypothesized that serum NGAL levels would be higher in patients with CAD and that serum concentration would correlate with the extent of CAD as documented by coronary angiography, serving as a potential biomarker of the severity of CAD.

Purpose: In patients with coronary artery disease, aspirin and Plavix are used increasingly to prevent the formation of blood clots in the coronary arteries. These drugs exert their beneficial effects by irreversibly blocking platelets, the compounds found in blood responsible for clotting after an injury or during a heart attack. However, these effects also place patients at increased risk for bleeding after coronary artery bypass surgery. Therefore, it is currently recommended to withhold Plavix therapy for 5 days before undergoing surgery in order to reduce the incidence of bleeding. However, it has been repeatedly shown that Plavix exerts variable effects on different patients, which may be partially explained by poor absorption, drug-drug interaction, and by variations in deoxyribonucleic acid (DNA) which constitutes your genes. In addition, the time required for platelets to regain function after Plavix treatment has been shown to vary between patients. Therefore, by measuring platelet function, it may be possible to determine the optimal amount of time required to withhold Plavix before undergoing bypass surgery, which may improve rates of bleeding following the procedure. The purpose of this study is to classify patients into groups based on platelet function in order to define the ideal time period for delaying surgery. By analyzing the amount of time required for platelet recovery, it is expected that surgery-related bleeding will decrease without increasing the risk of blood clot formation. Eligibility: Approximately 200 patients requiring CABG will be enrolled at Sinai Hospital, which is the only site where this study is being conducted. To be eligible you must: Be able to provide written informed consent. Be between the ages of 18-85 and require CABG. Currently be on aspirin therapy (81-325mg).

The specific aim of this proposed pilot study is to compare two standardized processes (paper and electronic) to deliver a customized MedlinePlus health information prescription.

Heart attacks are usually caused by a blood clot blocking an artery supplying blood to the heart. Current treatments are designed to relieve this blockage as quickly as possible to minimize damage to the heart muscle. However in restoring the supply of blood local damage known as "ischaemia-reperfusion injury" may occur. The aim of this study is to assess how clot forming and clot dissolving pathways are affected during this process, and examine the role of a natural inflammatory hormone, bradykinin. This will help the investigators to understand the mechanism by which ischaemia-reperfusion injury may occur and to devise new treatments for heart attacks.

Single center registry of patients who have received a Xience V everolimus-eluting stent at the Washington Hospital Center, with the primary objective to assess clinical success and safety at 30 days, 6 months and 1 year post-implantation.

To determine if prasugrel is superior to clopidogrel in providing adequate antiplatelet effect in a high risk population that requires concomitant use of a Proton Pump Inhibitor (PPI).