COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH:
Working… Menu

Effects of Body Mass Index on the Hyperemic Response to Regadenoson

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00859833
Recruitment Status : Completed
First Posted : March 11, 2009
Results First Posted : May 24, 2011
Last Update Posted : May 24, 2011
Astellas Pharma Inc
Information provided by:
University of Utah

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Obesity Endothelial Dysfunction Decreased Vascular Flow Drug: Adenosine Drug: Regadenoson Not Applicable

Detailed Description:

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.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 30 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: Single (Participant)
Primary Purpose: Diagnostic
Official Title: Effects of Body Mass Index on the Hyperemic Response to Regadenoson
Study Start Date : February 2009
Actual Primary Completion Date : July 2010
Actual Study Completion Date : July 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: myocardial perfusion reserve
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
Myocardial perfusion reserve measured with quantitative MRI during adenosine infusion (0.14 mg/kg/min x 6 minutes).
Other Name: adenoscan

Drug: Regadenoson
Myocardial perfusion reserve measured during regadenoson (0.4 mg/5 ml) bolus administration using quantitative perfusion MRI.
Other Name: Lexiscan

Primary Outcome Measures :
  1. Myocardial Perfusion Reserve Measured by Quantitative Perfusion MRI (Ratio of Myocardial Blood Flow During Stress Over Myocardial Blood Flow at Rest) [ Time Frame: 2 hours ]
    The ratio of myocardial blood flow during stress (with each vasodilator) divided by the myocardial flood flow at rest = myocardial perfusion reserve (MPR)

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 88 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • BMI 20-40 kg/m^2
  • age 18-88

Exclusion Criteria:

  • critically ill patients, patients on ventilators, patients with hypotension, asthmatics, and other patients whose medical care or safety may be compromised from undergoing an MRI examination will be excluded.
  • Patients with claustrophobia will also be excluded.
  • Also, anyone with contraindications to MRI (pacemaker, ICD, metal implants), pregnant subjects, minors, and prisoners will be excluded from this study.
  • If subjects are over 60 or have any suspicion of abnormal kidney function, a blood test to determine GFR will be performed prior to imaging.
  • Subjects with GFR < 30 will be excluded from the study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00859833

Layout table for location information
United States, Utah
University of Utah
Salt Lake City, Utah, United States, 84132
Sponsors and Collaborators
University of Utah
Astellas Pharma Inc
Layout table for investigator information
Principal Investigator: Sheldon E Litwin, MD University of Utah
Publications automatically indexed to this study by Identifier (NCT Number):
Layout table for additonal information
Responsible Party: Sheldon Litwin, M.D., Professor of Medicine, University of Utah Identifier: NCT00859833    
Other Study ID Numbers: 31431
First Posted: March 11, 2009    Key Record Dates
Results First Posted: May 24, 2011
Last Update Posted: May 24, 2011
Last Verified: May 2011
Keywords provided by University of Utah:
adenosine receptor subtypes
Additional relevant MeSH terms:
Layout table for MeSH terms
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Arrhythmia Agents
Vasodilator Agents
Purinergic P1 Receptor Agonists
Purinergic Agonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Adenosine A2 Receptor Agonists