PET Scan to Determine Areas of Blood Flow and Activity in the Hearts of Patients With Heart Disease Taking Beta-Blockers
Information source: National Institutes of Health Clinical Center (CC)
Information obtained from ClinicalTrials.gov on June 20, 2008
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Heart Failure, Congestive
Intervention: PET scan (Device)
Phase: Phase 2
Status: Completed
Sponsored by: National Heart, Lung, and Blood Institute (NHLBI)
Summary
The human heart is divided into four chambers. One of the four chambers, the left ventricle,
is the chamber mainly responsible for pumping blood out of the heart into the circulation.
Diseases of the heart like congestive heart failure (CHF), can cause the left ventricle to
function improperly.
Medications called beta-blockers appear to reverse the abnormalities in the left ventricle
and frequently improve the function of the left ventricle in patients with different kinds of
heart disease. How beta-blockers improve left ventricle function is unknown.
One possible reason for improved function of the left ventricle with beta-blockers is
improved blood flow to the heart muscle. When a region of the heart is active, it uses more
fuel in the form of oxygen and sugar (glucose). As heart activity increases, blood flow to
and from the area of activity increases also. Knowing these facts, researchers can use
radioactive sugar (glucose) and positron emission tomography (PET) scans to observe what
areas of the heart are receiving more blood flow.
In this study researchers plan to measure glucose use in heart muscle and blood flow to the
heart muscle in patients with CHF taking beta-blockers.
Clinical Details
Official title: Assessment of Metabolic Function and Perfusion Using Positron Emission Tomography: An Analysis of Patients With Congestive Cardiomyopathy Before and After Beta-Blockers
Study design: Treatment, Safety/Efficacy Study
Detailed description:
Deterioration in left ventricular function, which is characteristic in patients with
congestive heart failure, appears to be a multifactorial process. Beta-blockers appear to
reverse the deterioration and frequently improve left ventricular function in patients with
both ischemic and non-ischemic cardiomyopathies. The mechanism by which beta-blockers
improve ejection fraction is not known. Although it is well established that regional flow,
function and metabolism may improve after coronary revascularization whether beta-blocker
therapy will have similar salutary results in patients with congestive heart failure is
unknown. The aim of this study is to: 1) quantitate regional glucose uptake and regional
blood flow before and after chronic beta-blocker administration to patients with congestive
heart failure using positron emission tomography, 2) determine if alteration in either
regional glucose or lipid uptake or regional blood flow correlate with improvement in wall
motion and global left ventricular function, and 3) determine if ischemic and nonischemic
myocardium differ in blood flow or metabolism.
Eligibility
Minimum age: N/A.
Maximum age: N/A.
Gender(s): Both.
Criteria:
Left ventricular ejection fraction by radionuclide angiography of less than or equal to
40%.
New York Heart Association class II, III or IV symptoms on standard heart failure
medications which my include digoxin, diuretics and angiotensin converting enzyme
inhibitors for at least one month prior to enrollment.
Ischemic cardiomyopathy if enzymes document an MI or 70% or greater stenosis in one major
vessel.
Dilated cardiomyopathy-if no coronary disease.
No pregnant or lactating women.
No women of child-bearing age not on proven birth control.
No severe hepatic or renal disease.
No diabetes mellitus or fasting glucose greater than or equal to 120 mg/dl.
No primary valvular heart disease.
No PTCA or CABG within 3 months of enrollment.
No history of myocardial infarction or unstable angina within past 2 months.
No resting heart rate less than 60 bpm.
No A-V block greater than 1 degree block without pacemaker.
No severe ETOH abuse within 6 months of enrollment.
No severe bronchospasm.
Locations and Contacts
National Heart, Lung and Blood Institute (NHLBI), Bethesda, Maryland 20892, United States
Additional Information
Related publications: Eichhorn EJ, Heesch CM, Barnett JH, Alvarez LG, Fass SM, Grayburn PA, Hatfield BA, Marcoux LG, Malloy CR. Effect of metoprolol on myocardial function and energetics in patients with nonischemic dilated cardiomyopathy: a randomized, double-blind, placebo-controlled study. J Am Coll Cardiol. 1994 Nov 1;24(5):1310-20. Kjekshus JK, Mjos OD. Effect of free fatty acids on myocardial function and metabolism in the ischemic dog heart. J Clin Invest. 1972 Jul;51(7):1767-76. No abstract available.
Starting date: January 1994
Ending date: March 2001
Last updated: March 3, 2008
|
