Effects of Body Mass Index on the Hyperemic Response to Regadenoson

May 20, 2011 updated by: University of Utah
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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Utah
      • Salt Lake City, Utah, United States, 84132
        • University of Utah

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 88 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: DIAGNOSTIC
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: SINGLE

Arms and Interventions

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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)
2 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Utah

Collaborators

Astellas Pharma Inc

Investigators

  • Principal Investigator: Sheldon E Litwin, MD, University of Utah

Publications and helpful links

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General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2009

Primary Completion (ACTUAL)

July 1, 2010

Study Completion (ACTUAL)

July 1, 2010

Study Registration Dates

First Submitted

March 10, 2009

First Submitted That Met QC Criteria

March 10, 2009

First Posted (ESTIMATE)

March 11, 2009

Study Record Updates

Last Update Posted (ESTIMATE)

May 24, 2011

Last Update Submitted That Met QC Criteria

May 20, 2011

Last Verified

May 1, 2011

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 31431

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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