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67 active trials for Myocardial Ischemia

Evaluating Myocardial Ischemia in Chest Pain Using Exercise CMR

Ischemic Heart Disease (IHD) is a condition of recurring chest pain or discomfort that occurs when a part of the heart is not receiving sufficient blood flow. It is a major public health concern internationally and in Singapore, the leading cause of death from cardiovascular disease. Cardiovascular magnetic resonance (CMR) has the ability to assess heart structures, scarring or lack of blood supply to the heart muscle with great accuracy and without any radiation involved. A CMR-compatible cycle ergometer can offer a safe and low cost stress equipment to assess heart function and motion abnormalities, and restrictions of the blood supply to the heart tissues due to partial or complete blockages of the blood vessels. This study aims to develop an exercise-CMR stress protocol by testing its feasibility and robustness in assessing changes in cardiac volumes and function due to physical exertion in healthy individuals and to assess the accuracy of the multiparametric stress-CMR as a diagnostic tool for ischemic-causing coronary artery disease (CAD) with coronary fractional flow reserve (FFR) as a reference. to measure the overall economic impact of ischaemic heart disease by estimating the direct and indirect medical costs for each participant. The current sample costs will be extrapolated to estimate the annual costs of treating and managing ischaemic heart disease in the local population. to evaluate the effects of coronary microvascular dysfunction on coronary flow and regulation, physiological response and cardiac sympathetic signaling in patients with chest pain.

Start: May 2017
Determining the Mechanism of Myocardial Injury and Role of Coronary Disease in Type 2 Myocardial Infarction

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.

Start: October 2017

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) EXTENDed Follow-up (ISCHEMIA-EXTEND) is the long-term follow-up of randomized, surviving participants in ISCHEMIA. ISCHEMIA was an NHLBI-supported trial that randomized 5,179 participants with stable ischemic heart disease to two different management strategies: 1) an initial invasive strategy (INV) of cardiac catheterization and revascularization when feasible plus guideline-directed medical therapy (GDMT), or 2) an initial conservative strategy (CON) of GDMT. The trial did not demonstrate a reduction in the primary endpoint with an initial invasive strategy. There was an excess of procedural myocardial infarction (MI) and a reduction in spontaneous MI in the INV group. Prior evidence suggests that spontaneous MI carries a higher risk of subsequent death than procedural MI. There was a late separation in the cardiovascular (CV) mortality curves, over a median of 3.2 years follow-up in ISCHEMIA. The MI incidence curves crossed at approximately 2 years. Therefore, based on the observed reduction in spontaneous MI, it is imperative to ascertain long-term vital status to provide patients and clinicians with robust evidence on whether an invasive strategy reduces CV and all-cause death over the long-term. With projected 728 CV deaths we have adequate power to detect a between-group difference in mortality. We will also quantify the impact of nonfatal CV events on subsequent mortality in ISCHEMIA-EXTEND, construct a risk score for mortality using baseline deep phenotypic data, and provide estimates of the impact of the invasive strategy in the highest risk subgroup - those with severe coronary artery disease for whom current practice guidelines recommend coronary artery bypass (CABG) to improve survival. SPECIFIC AIMS Aim 1. To assess whether an initial invasive strategy reduces long-term CV mortality compared with an initial conservative strategy in SIHD patients with at least moderate ischemia on stress testing, over 10 years median follow-up. Aim 2. To assess the impact of nonfatal events on long-term CV and all-cause mortality Aim 3. To construct risk scores for CV and all-cause mortality using phenotypic data including clinical factors, stress test findings, and details of coronary anatomy. Condition: Coronary Disease Procedure: Observational Phase: Phase III per NIH Condition: Cardiovascular Diseases Procedure: Observational Phase: Phase III per NIH Condition: Heart Diseases Procedure: Observational Phase: Phase III per NIH

Start: July 2012