View clinical trials related to Coronary Circulation.
Filter by:The overall purpose of Flash FFR Ⅱ is to investigate whether coronary angiography-derived fractional flow reserve (caFFR), compared with fractional flow reserve (FFR) measured by a pressure wire, has non-inferior clinical effect and cost benefit in guiding the percutaneous coronary intervention (PCI) for patients with moderate coronary artery stenosis in terms of long-term clinical prognosis.
The overall purpose of the FAVOR III China trial is to investigate if a strategy of quantitative flow ratio (QFR)-guided percutaneous coronary intervention (PCI) yields superior clinical outcome and cost-effectiveness compared to a strategy of standard coronary angiography-guided PCI in evaluation of patients with coronary artery disease.
Angina is form of chest pain that is due to a lack of blood to the heart muscle. Angina is commonly triggered by stress and exertion, and is a common health problem worldwide. The diagnosis and treatment of angina is usually focused on detection of blockages in heart arteries, and relief of this problem with drugs, stents or bypass surgery. However, about one third of all invasive angiograms that are performed in patients with angina do not reveal any blockages. Many of such patients may have symptoms due to narrowings in the very small micro vessels (too small to be seen on an angiogram). The purpose of this research is to undertake a 'proof-of-concept' clinical trial to gather information as to whether routine tests of small vessel function in the heart might help identify patients with a stable coronary syndrome due to a disorder of coronary function (vasospastic or microvascular angina), and appropriately rule out this problem in patients with normal test results. The diagnostic strategy enables stratification of patient sub-groups to optimized therapy (personalised medicine). Evidence of patient benefits in this study would support the plan for a larger study that would be designed to impact on healthcare costs and patient reported outcome measures (PROMS).
Coronary artery disease (CAD) is the most frequent cause of mortality in the industrialized world. Hypercholesterolemia is a major risk factor for the development and progression of CAD. While statins currently represent the first-line, gold-standard therapy for primary and secondary prevention of cardiovascular morbidity and mortality, nearly 50% of patients in Europe and Canada treated with statins do not achieve their target levels of low-density lipoprotein cholesterol (LDL-C) or cannot tolerate effective statin doses. Recently, a growing number of studies of PCSK9 inhibitors in a wide spectrum of patients with hyperlipidemia on or off lipid-lowering therapy, familial hypercholesterolemia, and statin intolerance demonstrated consistent, profound, and sustained reductions in LDL-C with greater magnitude of reduction as compared with high-dose statin regimens. However, the effects of PCSK9 inhibition on coronary plaque morphology remain unknown. This study will investigate the effect of the PCSK9 inhibitor alirocumab in patients with acute myocardial infarction undergoing percutaneous coronary intervention (PCI) in the infarct-related artery and receiving guideline-recommended high-intensity statin therapy. A serial, multivessel, intravascular ultrasound, near-infrared spectroscopy and optical coherence tomography imaging study will be performed to determine the change in plaque volume at week 52. A total of 294 patients will be enrolled in the study and randomized in a 1:1 ratio to either alirocumab or placebo.
The study will compare two invasive methods (FFR -fractional flow reserve and iFR—instantaneous wave free ratio) for assessment of hemodynamic impact of coronary stenosis on myocardial perfusion. There is a very good correlation between these methods for the assessment of hemodynamic significance in a broad spectrum of lesions. However, this correlation decreases significantly near the cut off points for each method. The investigators will try to find possible explanations for these differences by detailed morphology assessment of coronary stenosis using optical coherence tomography (OCT), analysis of gene polymorphisms that play a role in vasodilatation, and by shear stress analysis. The head-to-head comparison between FFR and iFR is not simple, because there is no "gold standard" for assessment of hemodynamic significance. Studies comparing these methods have used hyperemic stenosis resistance (HSR). For this kind of measurement it is necessary to measure the speed of blood flow. This is usually done by a Doppler analysis of flow. Unfortunately, the Doppler signal can yield many artificial or erroneous indicators, and obtaining a good quality signal is frequently time-consuming. These are the reasons that HSR has not been used in routine practice. The investigators have developed a new console and software that can provide real time analysis of the Doppler signal. It allows us to easily measure HSR, and to differentiate between the FFR and iFR measures through intrabeat analysis of microvascular resistance (lowest microvascular resistance is an essential condition for proper pressure measurement). Using this tool, it is possible to automatically identify the point of lowest microvascular resistance during each cardiac beat. The pressure gradient can then be measured at that point. This approach can eliminate almost all uncertainties in assessment of the pressure gradient produced by coronary stenosis. This tool can potentially improve the existing methods used to precisely reveal a significant stenosis. This should increase the number of hemodynamic guided procedures.
The aim of this randomized controlled pilot study was to answer the following questions: 1. Is it possible to affect the diameter of coronary arteries through a placebo injection, which is administered intracoronarily together with a standardized verbal suggestion of coronary vasodilation? 2. Is it possible to affect the diameter of coronary arteries through a pharmacologically underdosed nitroglycerine injection, which is administered intracoronarily together with a standardized verbal suggestion of coronary vasodilation?