View clinical trials related to Myocardial Ischemia.
Filter by:Myocardial injury is common in patients without acute coronary syndrome, and therefore international guidelines propose a classification of patients with myocardial infarction by aetiology. This differentiates between myocardial infarction due to plaque rupture (type 1) and myocardial oxygen supply-demand imbalance (type 2) in other acute illnesses. However, these guidelines have not been widely adopted as the diagnostic criteria for type 2 myocardial infarction are not clearly defined. Patients with type 2 myocardial infarction have poor long term outcomes, with at least twice the mortality at five years compared to those with an index type 1 myocardial infarction. Despite the majority of deaths being attributable to non-cardiovascular events, the rate of future type 1 myocardial infarction or cardiovascular death is similar regardless of index classification. If this future risk is related to the presence of underlying coronary artery disease, then there may be the potential to improve outcomes through targeted investigation and secondary prevention. The investigators will undertake a systematic evaluation of the mechanism of myocardial injury and the role of coronary artery disease in 100 patients with elevated cardiac troponin concentrations where the diagnosis is likely to be type 2 myocardial infarction. These studies will help improve the assessment of patients with myocardial injury, refine the diagnostic criteria for type 2 myocardial infarction, and aid the design of future therapeutic trials.
this study is an individual patient level meta-analysis of randomized clinical trials, to evaluate the influence of ethnicity, to study whether the relative tradeoff between ischemia and bleeding is distinct by ethnicity.
The current study sought to evaluate the clinical relevance of iFR-guided strategy in real world clinical practice using unrestricted study population from stable angina to acute coronary syndrome including acute ST-segment elevation myocardial infarction. Previous abundant historical data of FFR-guided strategy will be also included as historical control to validate the iFR-guided strategy.
the purpose of this study is to determine whether appropriate control of diabetes around the PCI time is related with MACE and outcome of diabetic patients.
Benefits from cardiac rehabilitation (CR) programs are evidence based and widely recognized. Less than 50% of people who participate in hospital-based CR programs maintain an exercise regimen for as long as six months after completion. Despite the benefits associated with regular exercise training (ET), adherence with supervised exercise-based CR remains low. Current exercise guidelines for CR focus on moderate intensity steady state exercises, with walking and cycling being the most recommended types of ET. The repetitive nature of this type of activity can become monotonous for the patient, affecting exercise adherence, compliance and training outcomes. Exercise periodization is a method typically used in sports training, but the impact of periodized exercise to yield optimal beneficial effects in cardiac patients is still unclear. In healthy or trained populations, periodization aims to optimize ET adaptations as compared with non periodized training, to prevent overtraining and to avoid plateauing of training adaptations. Periodized methods are considered to be superior to non periodized methods in trained populations and appears to be superior in inactive adults. In most of the CR programs there are no periodization or exercise progression during medium to long term interventions. Further randomized controlled trials (RCT) are necessary to evaluate long-term periodization outcomes. The purpose of this research project is twofold: 1. To conduct a 12-month randomized control trial to evaluate the effects of a periodized ET regime versus a non periodized ET regime (guidelines) on VO2 peak, maximal strength, body composition, functionality and quality of life in cardiovascular disease patients. 2. to differentiate the effects of a 12-month periodized ET regime versus a non periodized ET regime on the different components of the oxygen kinetics response and oxidative adaptations in cardiovascular disease patients. These patients will be randomized in 2 ET groups: 1) periodization; 2) non periodization. This experimental design will occur during 48 weeks 3 times per week with 4 assessment time points: M0) before starting the ET program (baseline); M1) 3 months after starting the ET; M2) 6 months after starting the ET program and M3) 12 months at the end of the community-based ET program.
Apply a new operation method of Left Internal Mammary Artery (LIMA)-Greater Saphenous Vein (GSV)-SCVBG to the treatment of patients with diffuse coronary artery disease,through clinical randomized controlled study,compared with patients of bilateral internal mammary artery (BIMA)-SCVBG and evaluate both of therapeutic effects and prognosis.
The main purpose of our study is to investigate whether haemodialysis itself affects the efficacy of antiplatelet drugs and the effects of two different types of dialysis membranes (polysulfone membranes and polyamide membranes) on antiplatelet efficacy. A total of 60 patients with ESRD and under dual-antiplatelet treatmen for at least 5 days will be enrolled and divided into the Clopidogrel group (clopidogrel 75mg qd;aspirin 100mg qd, n=30) and the Ticagrelor group (ticagrelor 90mg bid; aspirin 100mg qd, n=30). All included patients will receive haemodialysis by two different types of dialysis membrane.Platelet aggregation of venous blood from all patients will be detected by LTA and VerifyNow immediately before and after two times of haemodialysis.
Remote ischemic preconditioning is a process of serial blood pressure cuff inflations and deflations that are performed prior to a procedure and have been shown in various other areas (coronary bypass surgery, vascular surgery, ST elevation myocardial infarctions) to decrease the rates of adverse events related to ischemic burden and renal injury. This procedure has not yet been studied in the population presenting with an acute coronary syndrome (ACS), even though ACS patients represent the majority of patients seen in the catheterization lab. The purpose of this study is to evaluate the efficacy of this simple and safe procedure in this particular population.
Because of its availability, non-invasiveness, and high diagnostic performance, myocardial perfusion tomoscintigraphy has become a standard tool for the detection, characterization and monitoring of coronary artery disease. Standard analysis, based on the reversibility of regional myocardial hypoperfusion between stress (physiological or pharmacological) and rest, has good sensitivity and negative predictive value in the search for myocardial ischemia. However, two major obstacles persist. First, because of the relative nature of the normalization of cardiac activity, this approach may underestimate the extent of the damage, especially when the territory with the most activity is itself pathological. Thus myocardial perfusion scintigraphy can only detect 40 to 50% of tri-truncal patients. To overcome these disadvantages, several indexes have been proposed to improve the diagnostic performance of perfusion scintigraphy in multi-truncal patients based in particular on kinetic analysis. Secondly, the review does not provide any guarantee as to the quality and reproducibility of use of the coronal reserve during stress, in particular during submaximal stress tests and pharmacological stress, the latter being easily antagonized by xanthine derivatives contained in tea and coffee in particular (abstinence of at least 12 to 24 hours being recommended). In recent years and thanks to the advent of CZT semiconductor cameras dedicated to cardiology - to perform a dynamic tomographic acquisition - a study of the coronal reserve is feasible by perfusion tomoscintigraphy in current practice. This study of the coronary reserve mainly consists of a computer post-processing of the myocardial perfusion scintigraphy data and does not therefore require any additional irradiation (the only difference with respect to the old protocols is the start of the images at the time of publication. injection of the radiotracer). However, the diagnostic benefit gained from the coronary reserve study compared to conventional stress / rest perfusion scintigraphy has not been clearly studied, particularly in the multi-truncal patients.
Coronary artery computed tomographic angiography (CTA) is a widely used, highly accurate technique for the detection of coronary artery disease (CAD), with sensitivity and negative predictive values of over 90% (1-4). Patients with normal CTA findings have an excellent prognosis and do not require further testing for CAD (5). However, like invasive coronary angiography (QCA), CTA is an anatomic test and, unless lesions are very severe (>90% stenosis), cannot reliably predict the impairment of flow (functional significance) of intermediate grade stenoses. For this reason, in approximately 15-25% of patients, additional functional testing may be required after CTA, usually in the form of stress testing (6-8). Stress testing is commonly done by exercise or pharmacologic stress with electrocardiographic monitoring and often, imaging of myocardial perfusion by nuclear scintigraphy (MPI) or detection of abnormal contraction by echocardiography. This requires a separate procedure, entailing time, expense and limited risk. Furthermore, in patients with previously known CAD, CTA alone is not an adequate test, because in most cases there are multiple lesions that are possible sources of ischemia. Over the last 10 years, these investigators and others around the world have developed a method of imaging myocardial perfusion by CT (CTP). This test is an adjunct to the usual Cardiac Computed Tomography Angiography (CCTA) procedure and can be done immediately thereafter, using conventional pharmacologic stress agents. It has demonstrated accuracy in many single center trials, and in this large multicenter study, the CORE320 trial (9,10) which showed a high accuracy in predicting the combined results of QCA plus MPI testing and a second multicenter trial established non-inferiority of myocardial CTP compared with nuclear stress testing (11,12). Additionally, this investigator group has published a direct comparison of diagnostic performance of myocardial CTP imaging and SPECT myocardial perfusion imaging and demonstrated superior diagnostic performance of CTP imaging compared with SPECT for the diagnosis of significant disease on invasive angiography (13). CTP images can be acquired with two different approaches: static or dynamic. In the CORE320 study, the CTP protocol used static acquisition method. The static CTP method, samples a snapshot of the iodine distribution in the blood pool and the myocardium over a short period of time, targeting either the upslope or the peak of contrast bolus. The notion behind this is that, at the upslope of the contrast, the difference in attenuation value of the ischemic and remote myocardium is at the maximum which enables for qualitative and semi-quantitative assessment of myocardial perfusion defects. The static CTP, however, does not allow for direct quantification of the myocardial blood flow (MBF). One of the drawbacks of static CTP lies in the acquirement of only one sample of data and the possibility of mistiming of the contrast bolus that results in poor contrast-to-tissue ratios by missing the peak attenuation (14). Output and flow rate of the contrast material may affect bolus timing. In addition, the acquisition of data from sequential heartbeats affects the attenuation gradient and may result in a heterogeneous iodine distribution, mimicking perfusion defects (15). Furthermore, the static CTP is limited in detection of balanced ischemia, where the perfusion of the entire myocardium is impaired and therefore there is no reference remote myocardium for comparison for semi-quantitative or qualitative static methods of CTP interpretation. Dynamic CT perfusion imaging uses serial imaging over time to record the kinetics of iodinated contrast in the arterial blood pool and myocardium. This technique allows for multiple sampling of the myocardium and the blood pool and creating time attenuation curves (TAC) by measuring the change in CT attenuation over time. Mathematical modelling of TACs permits for direct quantification of MBF. Despite its advantages, the use of dynamic CTP were limited in the past. A high temporal resolution and high number of detectors are required for dynamic CTP to allow for entire myocardial coverage, and in order to obtain multiple consecutive images at high heart rates(16,17). But the main challenge of dynamic CTP acquisition was the high radiation dose associated with this technique. Nevertheless, with the introduction of the cutting-edge 320 detector CT scanning systems with fast gantry rotation the issue of the cardiac coverage is eliminated(17). The second-generation 320-row scanners also permit the quantification of the MBF with dynamic CTP acquisition with relatively low-dose of radiation(18,19). In this study the investigators aim to evaluate the feasibility, safety and accuracy of the low-radiation dose dynamic myocardial CT perfusion compared to static CTP approach to detect hemodynamically significant coronary artery disease.