The Role of Angiotensin Type I Receptor in the Regulation of Human Peripheral Vascular Function
Primary Purpose
Atherosclerosis, Heart Failure, Congestive, Hypertension
Status
Completed
Phase
Phase 3
Locations
United States
Study Type
Interventional
Intervention
Angiotensin II type 1 receptor antagonists
Sponsored by
About this trial
This is an interventional treatment trial for Atherosclerosis focused on measuring Angiotensin Receptor Antagonist, Atherosclerosis, Blood Flow, Endothelium, Endothelial Dysfunction
Eligibility Criteria
Patients over 18 years with endothelial dysfunction requiring diagnostic cardiac catheterization. Normal volunteers or patients undergoing catheterization who have normal coronary arteries without risk factors for atherosclerosis will be used as controls. No unstable angina. No significant left main disease (greater than 50% stenosis). No recent myocardial infarction (less than 1 month). No pregnancy, lactation. No allergy to losartan. No renal failure (creatinine greater than 2.5 mg/dl). Ability to withdraw ACE inhibitors.
Sites / Locations
- National Heart, Lung and Blood Institute (NHLBI)
Outcomes
Primary Outcome Measures
Secondary Outcome Measures
Full Information
NCT ID
NCT00001628
First Posted
November 3, 1999
Last Updated
March 3, 2008
Sponsor
National Heart, Lung, and Blood Institute (NHLBI)
1. Study Identification
Unique Protocol Identification Number
NCT00001628
Brief Title
The Role of Angiotensin Type I Receptor in the Regulation of Human Peripheral Vascular Function
Official Title
The Role of Angiotensin Type I Receptor in the Regulation of Human Peripheral Vascular Function
Study Type
Interventional
2. Study Status
Record Verification Date
June 1999
Overall Recruitment Status
Completed
Study Start Date
July 1997 (undefined)
Primary Completion Date
undefined (undefined)
Study Completion Date
September 2000 (undefined)
3. Sponsor/Collaborators
Name of the Sponsor
National Heart, Lung, and Blood Institute (NHLBI)
4. Oversight
5. Study Description
Brief Summary
The renin angiotensin system (RAS) plays an important physiological and pathophysiological role in the control of blood pressure and plasma volume. Inhibition of the RAS is useful in the treatment of hypertension, cardiac failure and in some patients with myocardial infarction. Several recent clinical trials with angiotensin converting enzyme inhibitors (ACEI) have shown that they also reduce the incidence of myocardial infarction, but the mechanisms underlying this anti-ischemic effect are poorly understood. ACEI reduce angiotensin II synthesis and prevent bradykinin degradation. Results from ongoing studies in the Cardiology Branch (Protocol 95-H-0099) designed to investigate the link between ACEI and the vascular endothelium indicate that ACEI improve peripheral endothelial function, an effect that is partially mediated by bradykinin. The current protocol is designed to investigate whether the beneficial effects of ACEI on peripheral endothelial function are also due to inhibition of angiotensin II. The recent development of selective angiotensin II type 1 (AT1) receptor antagonists allows us to specifically examine the effects of angiotensin II on vasomotor activity.
Detailed Description
The renin angiotensin system (RAS) plays an important physiological and pathophysiological role in the control of blood pressure and plasma volume. Inhibition of the RAS is useful in the treatment of hypertension, cardiac failure and in some patients with myocardial infarction. Several recent clinical trials with angiotensin converting enzyme inhibitors (ACEI) have shown that they also reduce the incidence of myocardial infarction, but the mechanisms underlying this anti-ischemic effect are poorly understood. ACEI reduce angiotensin II synthesis and prevent bradykinin degradation. Results from ongoing studies in the Cardiology Branch (Protocol 95-H-0099) designed to investigate the link between ACEI and the vascular endothelium indicate that ACEI improve peripheral endothelial function, an effect that is partially mediated by bradykinin. The current protocol is designed to investigate whether the beneficial effects of ACEI on peripheral endothelial function are also due to inhibition of angiotensin II. The recent development of selective angiotensin II type 1 (AT1) receptor antagonists allows us to specifically examine the effects of angiotensin II on vasomotor activity.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Atherosclerosis, Heart Failure, Congestive, Hypertension, Myocardial Infarction
Keywords
Angiotensin Receptor Antagonist, Atherosclerosis, Blood Flow, Endothelium, Endothelial Dysfunction
7. Study Design
Primary Purpose
Treatment
Study Phase
Phase 3
Enrollment
36 (false)
8. Arms, Groups, and Interventions
Intervention Type
Drug
Intervention Name(s)
Angiotensin II type 1 receptor antagonists
10. Eligibility
Sex
All
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Patients over 18 years with endothelial dysfunction requiring diagnostic cardiac catheterization.
Normal volunteers or patients undergoing catheterization who have normal coronary arteries without risk factors for atherosclerosis will be used as controls.
No unstable angina.
No significant left main disease (greater than 50% stenosis).
No recent myocardial infarction (less than 1 month).
No pregnancy, lactation.
No allergy to losartan.
No renal failure (creatinine greater than 2.5 mg/dl).
Ability to withdraw ACE inhibitors.
Facility Information:
Facility Name
National Heart, Lung and Blood Institute (NHLBI)
City
Bethesda
State/Province
Maryland
ZIP/Postal Code
20892
Country
United States
12. IPD Sharing Statement
Citations:
PubMed Identifier
6736187
Citation
Ontyd J, Schrader J. Measurement of adenosine, inosine, and hypoxanthine in human plasma. J Chromatogr. 1984 May 11;307(2):404-9. doi: 10.1016/s0378-4347(00)84113-4. No abstract available.
Results Reference
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PubMed Identifier
7505360
Citation
Cockcroft JR, Sciberras DG, Goldberg MR, Ritter JM. Comparison of angiotensin-converting enzyme inhibition with angiotensin II receptor antagonism in the human forearm. J Cardiovasc Pharmacol. 1993 Oct;22(4):579-84. doi: 10.1097/00005344-199310000-00011.
Results Reference
background
PubMed Identifier
8403307
Citation
Gottlieb SS, Dickstein K, Fleck E, Kostis J, Levine TB, LeJemtel T, DeKock M. Hemodynamic and neurohormonal effects of the angiotensin II antagonist losartan in patients with congestive heart failure. Circulation. 1993 Oct;88(4 Pt 1):1602-9. doi: 10.1161/01.cir.88.4.1602.
Results Reference
background
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The Role of Angiotensin Type I Receptor in the Regulation of Human Peripheral Vascular Function
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