Stress Testing and Cardiac Magnetic Resonance

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to better define the role of a comprehensive stress MRI (which includes myocardial perfusion imaging, optimized coronary imaging, and myocardial scar imaging) in medical practice and in patient health management. Information gathered from the healthy volunteers that participate in this study will be compared to information from the coronary artery disease patients in this study in order to help further our understanding.

Detailed Description
-----------------
Coronary artery disease is a major cause of morbidity and mortality in the United States. Currently, the presence of physiologically significant coronary disease is most commonly diagnosed using non-invasive imaging tests such as a nuclear stress test or an echo stress test. Unfortunately, nuclear stress tests require the use of ionizing radiation and have a limited spatial resolution. On the other hand, echo stress tests are dependent of adequate imaging windows. Adenosine stress testing combined with cardiac magnetic resonance (CMR) is a rapidly evolving technique for diagnosing significant coronary disease. It does not use ionizing radiation and has excellent image quality. In a recent meta-analysis of 14 studies with a total of 1,183 patients, the sensitivity and specificity of stress CMR for detecting significant coronary disease was 91% and 81%. Additionally, 2 studies have shown that patients with a normal stress CMR study have a <1% risk of having a cardiovascular event during the ensuing year. Another important advantage to stress CMR is the ability to fully quantify myocardial blood flow which may improve the diagnostic accuracy of stress CMR. In addition to perfusion imaging, CMR can directly visualize the coronary arteries, detect extremely small myocardial infarctions, and precisely measure the left ventricular function. Although adenosine stress CMR is a rapidly maturing test, several important challenges exist. First, many patients find it difficult to tolerate the common side effects of adenosine in the confined space of the MRI scanner. Secondly, many patients under the influence of adenosine and its side effects cannot adequately hold their breath during image acquisition making image interpretation more difficult and quantitative analysis very time consuming. Finally, because adenosine must be continuously infused during a contrast-enhanced stress CMR, 2 separate intravenous (I.V.) catheters are needed. Most of the undesirable effects of adenosine are mediated through the adenosine A(2B) and A(3) receptors; where as, its desired vasodilator effects are mediated through the A(2A) receptor. The FDA recently approved an adenosine A(2A) receptor specific stress testing agent called regadenoson which is administered as a 10 second bolus and has an improved side effect and safety profile when compared to adenosine. With its improved tolerability and ease of use, regadenoson is a more ideal stress testing agent to use with CMR. The purpose of this study is to determine whether a comprehensive regadenoson stress cardiac magnetic resonance study which includes myocardial perfusion imaging, optimized coronary imaging, and myocardial scar imaging provides incremental prognostic information over a clinical evaluation that includes nuclear stress testing.

Official Title
-----------------
Stress Testing and Cardiac Magnetic Resonance

Conditions
-----------------
Coronary Disease

Intervention / Treatment
-----------------
* Drug: regadenoson


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Suspected coronary artery disease Symptoms of possible coronary artery disease Exclusion Criteria: Acute ST-elevation myocardial infarction Second or third degree AV block Severe Renal Disease (Glomerular Filtration Rate (GFR) <30cc/min or hemodialysis) Contra-indications to MRI (i.e. Implantable Cardioverter Defibrillator (ICD), pacemaker, aneurysm clip, etc) Hemodynamic instability Inability to provide informed consent Severe claustrophobia Pregnancy Age <18 years

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Open Label<br>Approximately 25 healthy volunteers will be recruited as controls. Scan will be done with regadenoson contrast. | Drug: regadenoson<br>* Subjects in open label group will be given a single dose of regadenoson (0.4 mg, i.e. 5 ml i.v. bolus) as contrast.<br>* Other names: Lexiscan;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major Adverse Cardiovascular Events | Major adverse cardiovascular events, such as death, myocardial infarction, unstable angina, congestive heart failure, or cerebral vascular accident. | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relationship Between SPECT and CMR Results of Myocardial Perfusion Imaging | Relationship between SPECT and CMR results of myocardial perfusion imaging for 1 Year | 1 year | 
| Optimization of Coronary Imaging Using CMR | Optimization of coronary imaging using CMR for 1 Year | 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Coronary Disease, Stress Testing, Lexiscan (regadenoson), Cardiac Magnetic Resonance Imaging