Active clinical trials for "Myocardial Infarction"

ST-segment elevation myocardial infarction (STEMI) is one of the most important causes of death and disability around the world. The main goal in the management of acute myocardial infarction (AMI) is early restoration of coronary artery flow in order to preserve viable myocardium. Primary percutaneous coronary intervention (PCI) has proven to be superior to other reperfusion strategies in terms of mortality reduction and preservation of left ventricular (LV) function. Despite improvements in the treatment of MI, 30% of patients show LV remodeling post-MI. Over time, remodeling adversely affects cardiac function and can lead to significant morbidity and mortality. Early risk stratification is essential to identify patients who will benefit from close follow-up and intense medical therapy. The most widely investigated functional left ventricular (LV) characteristic to predict patient outcome after STEMI is LV ejection fraction (LVEF). Several structural LV characteristics have also shown to be important predictors of cardiovascular adverse events and death, including LV end diastolic volume (LVEDV), end systolic volume (LVESV) and mass (LVM). Cardiovascular magnetic resonance (CMR) imaging is the current reference standard for assessing ventricular volumes and mass. Adverse remodeling results from an inability of the heart to maintain geometry post MI in the context of large infarcts and increased wall stresses. The compensatory hypertrophic response of the remote non-infarcted myocardium (end diastolic wall thickness (EDWT) and end systolic wall thickness (ESWT)) might also play an important role in the remodeling after myocardial infarction but this needs to be investigated. Infarct size -as a crucial endpoint for adverse remodeling- is influenced by several factors: - the size of the area at risk (AAR) (myocardium supplied by the culprit vessel); residual flow to the ischemic territory (e.g., collateral flow); myocardial metabolic demand; and the duration of coronary occlusion. Assessment of the size and distribution of the infarction area after revascularization therapy can facilitate prompt and appropriate clinical intervention. Biomarkers such as troponin and creatine kinase are mainly used for AMI identification but lack myocardial specificity and may overestimate the (IS). Left ventricle ejection fraction (LVEF) fails to detect minimal and early pathological changes. The myocardial damage following STEMI can be assessed accurately by delayed gadolinium enhancement imaging using CMR imaging. In the acute phase of a STEMI, the extracellular space is increased in the infarct region due to a combination of necrosis, hemorrhage, and edema. The extent of hyper enhancement in the acute phase has been related to the outcome in patients with STEMI. However, later on the necrotic tissue is replaced by fibrotic scar tissue also with increased extracellular space. This process leads to ongoing 'infarct shrinkage' after the first week until the infarction reaches its final size after ∼30 days. - - Measurement of hyper enhancement in the acute phase of an infarction might therefore overestimate the necrotic infarct size, whereas 'final extent of hyper enhancement' is more precisely related to the amount of necrotic tissue. In STEMI patients the prognostic importance and predictors of the final infarct size are not fully elucidated. Myocardial strain is a quantitative index based on measuring myocardial deformation during a cardiac cycle. Major tools for detecting changes in myocardial strain include CMR tagging, CMR feature tracking (FT-CMR) and speckle tracking echocardiography (STE). Previous studies have shown an advantage of strain in sensitively and accurately diagnosing and assessing IS compared to traditional functional indexes. However, the degree to which strain analysis can reflect the infarction areas quantified by CMR, adverse LV remodeling as well as the diagnostic accuracy of this analysis is still under dispute. In the past 3 years in particular, newly developed three-dimensional (3D) STE has overcome the inherent shortcomings of two-dimensional (2D) STE.

To describe the prescribing patterns at Methodist Dallas Medical Center (MDMC) for the treatment of newly diagnosed mural thrombus and to determine the efficacy and safety of DOACs apixaban, dabigatran, and rivaroxaban in comparison to warfarin. With limited treatment guideline consensus, minimal evidence to support the use of DOACs for Left Atrial Appendage (LAA) thrombus and Left Ventricular Thrombus (LVT), and a lack of evidence for the use of DOACs in aortic thrombus, further research is warranted to determine the role of DOACs in the treatment of various mural thrombi in comparison to warfarin.

Cangrelor is a fast and directly acting platelet aggregation inhibitor. It is potentially indicated for several types of patients who are undergoing PCI. A nationwide cangrelor registry has up until now not been performed and with the introduction of cangrelor in the Netherlands its efficacy and safety will be determined.

Until now it has been assumed that regular endurance training has a positive influence on cardiac function and that the positive effect increases with increasing intensity. However, little is known about the effects of intense endurance stress on the heart. According to current knowledge repeated exposure to strenuous endurance activity may lead to minor but possibly irreversible damage to the heart with resultant scarring of the heart's muscle. Within this study the investigators attempt to find out by different analytical methods - in particular magnetic resonance imaging (MRI) and ultrasound of the heart - to what extent the heart muscle is affected by long term intense endurance exercise and which changes in cardiac function and morphology can possibly be found. Therefore the investigators compare former national competitive endurance athletes with sedentary controls.

Left atrial volume (LAV) provides the significant prognostic information in the general population and patients with heart disease, including acute myocardial infarction, left ventricular dysfunction, mitral regurgitation, cardiomyopathy and atrial fibrillation. Large left atrial volume, which represents chronic diastolic dysfunction, is associated with poor outcome, regardless of systolic function. Thereby, LAV provides a long-term view of whether or not the patient has the disease of diastolic dysfunction, regardless of whatever loading conditions are present at the time of the examination, as the hemoglobin A1C in diabetes. However, whether left atrial (LA) parameters could correlate with LVFP and reflect short-term change in left ventricular filling pressure(LVFP) remains unknown. Only one article of our team confirmed the relationship between LAV and LVFP in patients with severe mitral regurgitation by simultaneous echocardiography-catheterization. The prior report proposed a new parameter, LA distensibility, and disclosed its logarithmic relationship with LVFP. The LA distensibility precisely indicated rapid change in LVFP of patients with acute severe mitral regurgitation, and was even superior to mitral E/Em (early-diastolic mitral inflow velocity divided by early-diastolic mitral annular velocity). As left atrial pressure rises to maintain adequate left ventricular diastolic filling, increased atrial wall tension tends to dilate the chamber and stretch the atrial myocardium. Therefore, the smaller left atrial stretchability, the more pressure left atrium (LA) faces to. The first objective of this study was to test the value of LA distensibility for assessing LVFP, particularly in patients with acute myocardial infarction. The second objective was to assess the prognostic value of LA distensibility.

Background: Dual antithrombotic treatment with aspirin and clopidogrel is recommended in patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The European Society of Cardiology (ESC) Guidelines recommend a bolus dose of aspirin of 250-500 mg and a 600 mg bolus dose of clopidogrel as soon as STEMI is suspected. Studies have shown that more newly produced platelets are present in the acute phase of STEMI, and it is likely that these immature platelets are haemostatically more active and might be of importance in thrombus formation. The enhanced platelet reactivity may reduce the effect of aspirin and clopidogrel in the acute phase of STEMI compared to measurements made in the same patients 3 months after primary PCI. Aim: This study aims to compare platelet response to aspirin and clopidogrel in the acute phase of STEMI with the platelet response in the same patients 3 months after STEMI . Design: This study is an observational follow-up study. Materials and methods: 46 patients with STEMI referred to primary PCI at Aarhus University Hospital, Skejby will be included in the study. A total of 3 blood samples are obtained in the acute phase of STEMI: Prior to primary PCI (Blood sample 1), at 4 hours (Blood sample 2) and at 12 hours (Blood sample 3) after administration of loading dose aspirin and clopidogrel. When patients are in a stable phase 3 month later, a final blood sample is taken (Blood sample 4). The blood is analyzed 30 minutes after withdrawal of blood by the platelet aggregation test Multiplate® aggregometry (agonists: Collagen, arachidonic acid and adenosinediphosphate) and VerifyNow® arachidonic acid and P2Y12 aggregometry. Platelet count, volume and the immature platelet fraction (IPF) will be measured using Sysmex® flowcytometry.

The purpose of this study is to compare p53-induced genes activation as possible markers differentiating between patients presenting with acute myocardial infarction and controls.

Magnetic resonance imaging (MRI) and echocardiography are two imaging methods that are used to obtain pictures of the heart and assess heart function. This study will evaluate a new, four-dimensional echocardiography approach of obtaining heart images to determine if it is as effective at evaluating heart function as MRI.

The goal of this research is to determine noninvasively whether detection of coronary stenosis and plaque by multidetector computed tomography (MDCT) in patients with acute chest pain suspected of acute coronary syndrome (ACS) enhances triage, reduces cost and is cost effective. Among the 5.6 million patients with ACP presenting annually in emergency departments (ED) in the United States, a subgroup of two million patients is hospitalized despite normal initial cardiac biomarker tests and electrocardiogram (ECG). This subgroup is at low (20%) risk for ACS during the index hospitalization. Most (80-94%) patients with a diagnosis of ACS have a significant epicardial coronary artery stenosis ( >50% luminal narrowing). However, in -10% of patients non-stenotic coronary plaque triggers events, i.e. vasospasms, leading to myocardial ischemia. Since the absence of plaque excludes a coronary cause of chest pain, these patients could in theory be discharged earlier reducing unnecessary hospital admissions. Recent publications demonstrate high sensitivity and specificity of MDCT for the detection of significant coronary stenosis compared with coronary angiography and the detection of coronary plaque as validated with intravascular ultrasound. Using 64- slice MDCT we propose to study 400 patients with ACP, negative initial cardiac biomarkers and non-diagnostic ECG. We will analyze MDCT images for the presence of significant coronary artery stenosis and plaque and correlate the data with the clinical diagnosis of ACS (AHA guidelines) during the index hospitalization to determine the sensitivity and specificity. MDCT data, risk factors, and the results of standard diagnostic tests available at the time of MDCT will be used to generate a multivariate prediction function and derive a clinical decision rule. Based on this decision rule we will compare the diagnostic accuracies and cost effectiveness of competing strategies. We hypothesize that an MDCT- based diagnostic strategy will reduce the time to diagnosis of ACS, number of hospitalizations, and absolute cost of management of patients with acute chest pain compared to standard clinical care and is cost effective.

Despite recent improvements in treatment, myocardial infarction (heart attack) is still a leading cause of illness and death in the UK. Following the acute event, it is difficult to predict which patients are at risk of further problems, such as heart failure and is therefore difficult to know which patients need more aggressive/intensive treatment and monitoring. There needs to be a test which is safe, reliable and reproducible that can be used shortly after a heart attack to both predict future cardiac events and to allow the efficacy of new treatments to be assessed. Myocardial oedema (swelling of the heart muscle) has been demonstrated using Cardiac Magnetic Resonance (CMR), to occur following a heart attack and has been suggested as a marker for future cardiac events. The optimum time to perform this scan, the method of data analysis and it's effectiveness as a predictor of future cardiac events has not been adequately assessed. This trial will assess the amount and natural time-course of oedema in the first 10 days following a heart attack. It will also correlate the amount of oedema with the size of scar (damaged heart muscle) and left ventricular ejection fraction (heart function) at 3 months to assess if it is a predictive marker.