Does Caffeine Affect the Sensitivity of Adenosine Perfusion Scans?

Study Overview
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Brief Summary
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We are studying the affect of caffeine on the sensitivity of detecting coronary artery disease (blockages in the blood flow to the heart) with adenosine tracer scans. Adenosine is a drug used routinely in patients to relax heart blood vessels in order to assess for the presence of coronary artery disease. Often, if patients have had caffeine, the adenosine scan is not used because of the belief that caffeine may reduce the ability to detect coronary artery disease. We would like to test whether caffeine affects our ability to detect coronary artery disease with adenosine tracer scanning. We will perform an imaging study of the heart with adenosine after you have received caffeine.

Official Title
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Does Caffeine Affect the Sensitivity of Adenosine Perfusion Scans?

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Procedure: Cardiac SPECT imaging Rest and Stress
* Drug: Caffeine
* Drug: Caffeine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have already completed rest/stress 99mTc sestamibi or 99mTc tetrofosmin imaging will be given a form describing this protocol and asked to volunteer for the additional scan Exclusion Criteria: history of asthma, bronchospastic COPD, or renal failure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>Caffeine 400 mg PO 1 hour before adenosine infusion | Procedure: Cardiac SPECT imaging Rest and Stress<br>* adenosine perfusion scintigraphy<br>Drug: Caffeine<br>* Caffeine 400 mg po<br>|
| Active Comparator: 2<br>Caffeine 200 mg po one hour before adenosine infusion | Procedure: Cardiac SPECT imaging Rest and Stress<br>* adenosine perfusion scintigraphy<br>Drug: Caffeine<br>* Caffeine 200 mg po<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| This protocol has a specific aim of determining whether prior caffeine administration affects the sensitivity and specificity of adenosine perfusion scintigraphy for detection of impaired coronary vascular reserve. |  | Assessment is made at the time of research adenosine perfusion scintigraphy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| determination of caffeine levels in patients instructed to hold caffeine prior to adenosine imaging |  | Assess at time of lab sample results obtained | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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adenosine tracer scans, coronary artery disease, caffeine