Evaluation of Myocardial Ischemia Using Standard Single Photon Emission Computed Tomography (SPECT) With Regadenoson and Simultaneous Cardiac Echocardiography

Study Overview
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Brief Summary
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This study is for people who have a SPECT scan (nuclear imaging of the blood flow to the heart muscle) ordered by their medical doctors. As part of the SPECT scan, they will have been given a drug called regadenoson to widen and expand the blood vessels bringing blood to the heart muscle. The SPECT pictures of the heart are taken about an hour after the regadenoson is put into an arm vein through an IV. In this study, additional echo pictures will be taken and compared to the SPECT pictures. The aim of the study is to see if the echo pictures work as well as SPECT to measure the blood flow to the heart muscle.

Detailed Description
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This is a single center, prospective, non-randomized, comparative, same-setting study of Lexiscan MPI SPECT versus state-of-the-art echocardiography. Lexiscan SPECT MPI will be performed per routine clinical protocol with Lexiscan administered as per package insert (0.4 mg in 5 ml IV push over 10 seconds followed by a 5 ml saline flush). Simultaneous echo/Doppler will be obtained immediately before (baseline), during and immediately post (peak vasodilation) using conventional techniques.

Official Title
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Lexi-Echo - a Rapid, Portable, Non-radiating Diagnostic Test for Myocardial Ischemia That is Accurate Relative to Simultaneously Obtained Nuclear SPECT MPI

Conditions
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Myocardial Ischemia

Intervention / Treatment
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* Drug: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients referred to a University of Arizona/Sarver Heart Center/University Medical Center stress imaging laboratory and scheduled to receive a regadenoson SPECT nuclear scan. Exclusion Criteria: Patients unable or unwilling to undergo the clinically necessary stress test or to provide informed consent.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Lexi-Echo pilot<br>Appropriate patients at University of Arizona Medical Center stress imaging laboratory who have a routine regadenoson SPECT nuclear scan will have simultaneous cardiac echo images obtained. | Drug: No intervention<br>* No intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determine the diagnostic accuracy of state-of-the-art echocardiography after regadenoson administration (Lexi-Echo) in the evaluation of myocardial ischemia (determined by the reference standard myocardial perfusion imaging SPECT). |  | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Obtain short term (6 month) outcomes: hospitalization for ischemia or infarction, coronary angiographic (invasive or noninvasive) correlation when available for clinical indications, and mortality. |  | 6 months | 
| Perform a limited cost-analysis of the two diagnostic testing options |  | 6 months | 
| Obtain hemodynamic Doppler Echo variables to investigate the acute hemodynamic alterations during Lexiscan infusion. |  | 10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Echocardiography, 2D, speckle tracking, Lexiscan, regadenoson, Myocardial ischemia, Myocardial perfusion imaging, cost and cost analysis, Cardiac-Gated SPECT Imaging, Echocardiography