Active clinical trials for "Coronary Artery Disease"

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).

This study aims to evaluate the role of leukocyte activation in coronary artery disease

Instantaneous wave-free ratio (iFR™) is a novel non-hyperaemic index of the functional significance of a coronary stenosis. Previous studies have shown variable levels of correlation with the established hyperaemic index FFR. In addition it has been proposed that iFR™ has superior diagnostic accuracy when compared to mean whole cardiac cycle Pd/Pa which can also be used to predict FFR. We plan to undertake a prospective clinical study in consecutive patients already undergoing FFR assessment in the cardiac catheterisation laboratory to compare the ability of iFR™ and Pd/Pa (both measured using the proprietary Volcano system) to predict FFR. We will explore the level of misclassification of flow limiting disease that results from use of iFR™ and resting Pd/Pa employed using either binary cut-off algorithms or in a hybrid decision making protocol. We plan to analyse 260 vessels over a 18 month period. Hyperaemia will be induced by intravenous adenosine (140 ug/kg/min) administered wherever possible via an antecubital vein. Intra-coronary nitrates will also be given in line with the standard care procedure for FFR measurement. Final clinical decisions following coronary physiology will be based on steady state FFR.

Hypothesis: A validated technique to measure cardiac output (CO) using echocardiography is to calculate stroke volume from the product of LVOT area and LVOT VTI and multiplying the product with heart rate ( CO = SV x H/R; SV = LVOT area x LVOT VTI ). The LVOT diameter for an individual is more or less a constant measurement. Therefore using the formula mentioned above (SV = LVOT area x LVOT VTI), if the LVOT area is constant, then SV should be proportional to the VTI. This means if a PLR manoeuvre or fluid bolus helps to achieve a rise in SV, then it should be reflected in an increase in VTI as well. If this assumption is true, then an increase in the value of VTI from baseline after fluid challenge (10-15%), should identify a volume responsive patient.

The effect of antiplatelet therapy is impaired among patients, who recently underwent on-pump coronary artery bypass grafting. The impact of hybrid coronary revascularization using minimal invasive surgical techniques on the antiplatelet effect of aspirin and clopidogrel remains unclear. The aim of the study is to describe the impact of hybrid coronary revascularization on the effect of aspirin and clopidogrel. Furthermore, we will investigate whether high baseline platelet aggregation, high postoperative levels of platelet turnover and acute-phase response may contribute to the effect.

The purpose of this observational registry was to compare the safety and efficacy of an antithrombotic regimen comprising one single antiplatelet agent plus an oral anti-thrombotic versus those consisting of DAPT alone or DAPT plus oral antithrombotic therapy. This registry assessed whether the antithrombotic therapy intensity would vary positively with physician perceived ischemic risk at the time of percutaneous coronary intervention (PCI), and whether an inverse association would be observed with perceived bleeding risk. This study also evaluated the physician use of objective benefit-risk assessment scores and their influence on prescription of antithrombotic therapy in atrial fibrillation (AF) patients undergoing PCI. Additionally the study investigated whether patient perceived relevance and accessibility of anti-platelet and anticoagulant treatment regiments would predict treatment adherence and whether non-adherence would independently influence outcome. Approximately 514 subjects with non-valvular AF undergoing all-comer PCI were enrolled at 11 sites in North America and Europe. Follow-up was done via telephone by trained research coordinators at each participating site at 30 days, 6 months and 12 months.

The aim of the study is to evaluate platelet function variations according to the delay since last aspirin intake (12 vs 24 hours)in a population of diabetic patients with previous Coronary Artery Disease.

No previous study has assessed the potential of ranolazine to interfere with levels of platelet reactivity in patients with coronary artery disease who are treated with dual antiplatelet therapy. Aim of this study is to compare the pharmacodynamic effects of maintenance doses of ranolazine versus amlodipine on platelet reactivity in patients with coronary artery disease who are treated with dual antiplatelet therapy.

"The impact on fluid loading after cardiac surgery by use of two different priming solution" Fluid overloading with oedema formation is a regular finding following on-pump cardiac surgery and may contribute to postoperative organ dysfunction. Myocardial oedema has been reported to impair both systolic and diastolic function. An association between intraoperative fluid loading and postoperative adverse outcome has been demonstrated in cardiac patients. The investigators have experience with the use of both colloides and combination fluids (hypertonic saline/colloides) in several experimental studies (pigs). In one animal study the investigators used colloides as an additive to the CPB-prime. The investigators observed reduced fluid leakage and less total tissue water in several organs. The planned study includes patients scheduled for coronary artery bypass, and who have no co-morbidity. The patients will be randomized to receive either Tetraspan® (HES) or acetated Ringer's solution in the CPB-prime. Accurate accounts of fluid additions, blood loss and diuresis will be kept. Determination of cardiac output (C.O.), intrathoracic blood volume (ITBV), extravascular lung water (EVLW) and global end diastolic volume (GEDV) will be monitored by use of the transpulmonary thermodilution technique PiCCO®plus system.

The investigators aim to compare the cost-effectiveness of CCTA and myocardial SPECT in patients with intermediate pre-test probability of CHD. To this end, patients with intermediate pre-test probability of CHD will be randomized 1:1 to either CCTA and myocardial SPECT. The patients will be analyzed for cost and also, for outcome.