An interventional study of Adenosine and Regadenoson in Obesity, Endothelial Dysfunction and Decreased Vascular Flow, sponsored by University of Utah. Completed at 1 site in United States. Open to participants aged 18 Years to 88 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2011-05-24.
Sponsored by University of Utah · Not applicable, Interventional, and Diagnostic
We will test the hypothesis that a single dose of Regadenoson will produce equivalent degrees of coronary hyperemia in patients of widely different body size. This will be a prospective, open-label, comparative trial using MRI to measure myocardial perfusion reserve (ratio of myocardial blood flow with vasodilator to myocardial blood flow at rest) during sequential administration of the coronary vasodilators adenosine and regadenoson. Non-invasive MRI measurements of resting myocardial blood flow, and sequential measurements of blood flow during adenosine infusion (weight adjusted dosing) and then blood flow during regadenoson infusion (single, fixed dose. Blood flow measurements will be obtained sequentially and in the same sequence in each subject during a two hour MRI exam. 32 subjects will be recruited for this study. The first 2 will be for testing of the protocol. Inclusion criteria: 2 subjects for initial protocol evaluation, then 30 subjects with body mass index (BMI) between 18 and 40. Exclusions are pregnancy, renal dysfunction and claustrophobia.
Introduction: Regadenoson (Lexiscan) is currently recommended for use as a targeted vasodilator in myocardial perfusion studies and is available as a single, fixed dose for all patients. Here we propose to compare the hyperemic response measured with MRI in subjects with a wide range of BMI 18-40.
MRI is an ideal test to compare the effects of regadenoson in patients with different body mass indices (BMIs). No radiation is used and multiple perfusion tests can be performed in close temporal sequence. Importantly, a number of researchers have shown the ability to obtain quantitative stress and rest myocardial blood flow values in the heart with MR imaging. This allows the calculation of myocardial perfusion reserve (MPR). Flow reserve measurements also can be done with dynamic PET, but not with SPECT. PET has the disadvantage of radiation exposure.
Regadenoson may be a more desirable agent for use with MRI than is adenosine. Adenosine requires the use of 2 intravenous lines, and the use of either a specialized, expensive, MRI-compatible infusion pump to deliver the drug, or long lengths of tubing to run to a pump outside the scanner room. Neither solution is ideal. Regadenoson does not require any such pumps or the starting of a second i.v.. The work here would accomplish 2 goals: 1) to demonstrate the feasibility of performing quantitative MRI perfusion measurements with regadenoson, and 2) to test whether a single dose of regadenoson produces maximal coronary hyperemia across a wide range of body sizes.
Study Design: This will be a prospective, open-label, study. The design is single group, one arm, 2 interventions in which we will compare MPR measured sequentially during adenosine and regadenoson using MRI. Non-invasive MRI measurements of resting flow, flow at adenosine stress, and flow at regadenoson stress will be obtained sequentially in each subject during a single two hour MRI exam. Each drug will be given in the same order to all subjects.
32 subjects will be recruited for this study. The first two subjects will be imaged only with resting perfusion, in order to determine optimal acquisition parameters for the study, and will not be used in the analysis. The main outcome measure is MPR with each agent.
University of Utah is the lead sponsor of 969 studies on the registry; 178 are open to participants now.
Of its 107 completed or terminated interventional studies of FDA-regulated products, 62 (58%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Myocardial perfusion reserve will be measured by quantifying myocardial blood flow using MRI at rest and then with each of 2 coronary vasodilators. Measurements are performed with first pass gadolinium perfusion (i.v. bolus injection of 0.02 or 0.03 mmol/kg of gadolinium). Each of the 2 drugs is given sequentially (30 minutes apart) in the same sequence in every patient. The shorter acting drug (adenosine) is given first so it has time to wear off before giving the second drug. It is ideal to measure MPR with each drug during the same imaging session so that there are no other clinical variables that change between the administration of the 2 agents. See below.
Drug: Adenosine · Drug: Regadenoson
Myocardial perfusion reserve measured with quantitative MRI during adenosine infusion (0.14 mg/kg/min x 6 minutes).
Also known as: adenoscan
Myocardial perfusion reserve measured during regadenoson (0.4 mg/5 ml) bolus administration using quantitative perfusion MRI.
Also known as: Lexiscan
Myocardial Perfusion Reserve Measured by Quantitative Perfusion MRI (Ratio of Myocardial Blood Flow During Stress Over Myocardial Blood Flow at Rest)
The ratio of myocardial blood flow during stress (with each vasodilator) divided by the myocardial flood flow at rest = myocardial perfusion reserve (MPR)
Time frame: 2 hours
Patients were recruited from medical clinics and by advertising within the hospital.
| Milestone | Adenosine Followed by Regadenoson |
|---|---|
| Started | 30 |
| Completed | 30 |
| Not completed | 0 |
The ratio of myocardial blood flow during stress (with each vasodilator) divided by the myocardial flood flow at rest = myocardial perfusion reserve (MPR)
| ratio | Adenosine | Regadenoson |
|---|---|---|
| Myocardial Perfusion Reserve Measured by Quantitative Perfusion MRI (Ratio of Myocardial Blood Flow During Stress Over Myocardial Blood Flow at Rest) | 2.25 ± 0.59 | 2.44 ± 0.91 |
Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Adenosine Followed by Regadenoson | — | 0/30 (0%) | 0/30 (0%) |
| Age Continuous(years) | Adenosine Followed by Regadenoson |
|---|---|
| Mean | 49.5 ± 11.5 |
| Age, Customized(participants) | Adenosine Followed by Regadenoson |
|---|---|
| Between 18 and 65 years | 30 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | Adenosine Followed by Regadenoson |
|---|---|
| Female | 13 |
| Male | 17 |
| Region of Enrollment(participants) | Adenosine Followed by Regadenoson |
|---|---|
| United States | 30 |
This study is completed, as verified in May 2011. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Utah