Active clinical trials for "Myocardial Ischemia"

The aim of this study is to determine if stress first pass imaging in conjunction with a nuclear scan will improve the sensitivity for detecting heart disease. This study will also test the usefulness of a nuclear medicine camera, CDLCAM One Pass Angiography system.

This purpose of this research project is to test the diagnostic accuracy (i.e., sensitivity, specificity, positive and negative predictive value, and receiver operator curve area under the curve) of cardiac computed tomography (CT) perfusion as compared to the best non-invasive test of blood flow -- cardiac positron emission transmission (PET) perfusion imaging. The primary outcome of the study is to determine the CT perfusion technique with the highest overall diagnostic accuracy measured by the highest area under the receiver operator curve. The investigators will test 4 different CT perfusion techniques. (A) Qualitative, visual inspection of the contrast-enhanced CT images (B) Enhanced voxel distribution analysis (C) Rate of myocardial contrast enhancement analysis (D) Quantitative heart blood flow using a distributed 2-region analysis A second aim is to reduce the radiation dose needed to maintain CT perfusion diagnostic accuracy. Using the CT perfusion data, the investigators will model the minimal number of cardiac cycle radiation exposures needed to keep the diagnostic accuracy similar to the full data set. A third aim is to test the incremental diagnostic accuracy of CT angiography plus CT perfusion to identify regions of low blood flow as compared to PET perfusion alone.

The investigators examined the feasibility of treatment planning using virtual coronary revascularization and fractional flow reserve (FFR) CT before the invasive procedures.

The purpose of the study is to optimize an already existing algorithm for diagnosing atherosclerosis of the coronary arteries (CAD, Coronary Artery Disease).

The purpose of this study is to assess the non-invasive, Peripheral Arterial Tonometry (PAT) testing as another way of predicting potential coronary artery blockages in the heart.

Most patients presenting to the emergency department with chest discomfort have a nonischemic ECG and biomarkers of myocardial necrosis within normal limits. These patients are routinely admitted to hospital because of diagnostic uncertainty for occult MI or ischaemia. Acute myocardial ischemia is associated with acute mycardial dysfunction We tested a non-invasive plethysmographic arterial pressure change index of myocardial performance (dP/dt) that could be added to the diagnostic triage of ischaemia in the ER avoiding unnecessary admissions.

The study seeks to determine the accuracy of using anatomic and physiologic information measurable by computed tomography features of stenosis, plaque, fractional flow reserve-CT and to compare this measure to stress testing for the detection of myocardial ischemia against the gold standard of cardiac catheterization with fractional flow reserve. The hypothesis of this proposal is that integrating anatomic plaque features with physiologic fractional flow reserve-CT will optimize identification of coronary lesions that are ischemia-causing by computed tomography .

This study is being done to compare the blood flow measurements obtained with the SPECT and PET imaging scans. Measurements such as myocardial blood flow (MBF) and myocardial flow reserve (MFR) are analyzed on PET scans. These measurements give the doctors more precise information in diagnosing heart problems. SPECT scans, with new camera technology and computer software, now have the potential to also give this additional information. The study is investigating how well the blood flow measurements from SPECT compared to PET.

The investigators propose a 4 year prospective, observational study of 40 patients yearly, comparing conventional clinically indicated SPECT and PET perfusion with dynamic rest/stress MPI studies with coronary angiography, in some cases performed with quantitative coronary anatomy and flow as well as quantitative 13N-ammonia PET MPI. Methods will also be assessed for their ability to determine myocardial viability by comparing regional wall motion (WM) on clinically indicated serial ventriculography, echocardiography or gated SPECT MPI in those protocol patients with WM abnormalities who subsequently undergo revascularization. Patient studies will begin in the first study year based on those methods already developed and integrate new advances as they become evident.

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