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Genes, Fibrinolysis and Endothelial Dysfunction- Dialysis Aim 3

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ClinicalTrials.gov Identifier: NCT00878969
Recruitment Status : Terminated (insufficient enrollment and retention)
First Posted : April 9, 2009
Results First Posted : February 15, 2016
Last Update Posted : February 15, 2016
Sponsor:
Collaborators:
University of Washington
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Alp Ikizler, Vanderbilt University

Brief Summary:
The purpose of the study is to see how two classes of blood pressure medications,angiotensin-converting enzyme inhibitors (Ace inhibitors) and angiotensin receptor blockers (ARBs), differ in their long term effects on certain chemicals in the body and on the carotid arteries.

Condition or disease Intervention/treatment Phase
Oxidative Stress Endothelial Dysfunction Drug: valsartan (ARB) Drug: ramipril (ACE inhibitor) Drug: Placebo Phase 3

Detailed Description:

More than 400,000 individuals with chronic kidney disease undergo hemodialysis each year in the United States. Atherosclerotic cardiovascular disease is the leading cause of mortality in these patients. Conventional risk factors for coronary artery disease (CAD) do not adequately explain this increased mortality, whereas biomarker of oxidative stress and inflammation correlate with clinical outcomes. Even with the use of biocompatible membranes, hemodialysis induces a systemic inflammatory reaction characterized by complement activation, leukocyte activation and the generation of reactive oxygen species and cytokines. Oxidative stress and inflammation promote endothelial dysfunction, a predictor of atherosclerotic cardiovascular events.

The purpose of the study is to test the hypothesis that angiotensin-converting enzyme inhibition and angiotensin receptor blockade differ in their long term effects on biomarkers of fibrinolysis, oxidative stress,inflammation and on carotid intima-media thickness (IMT), a predictor of cardiovascular events, in patients with chronic kidney disease undergoing maintenance hemodialysis.

Endogenous Bradykinin (BK) contributes to the hypotensive and pro-fibrinolytic effects of ACE inhibitors. It has been determined that endogenous BK contributes to the vasodilator effects of acute and chronic ACE inhibition. Studies have found that BK stimulates vascular tissue plasminogen activator (t-PA) release through a BK B2 receptor-dependent, nitric oxide (NO) and cyclooxygenase-independent pathway. Hemodialysis patients demonstrates endothelial dysfunction. Data suggests that t-PA release may be attenuated during stimulation of the endogenous kallikrein-kinin system by hemodialysis.

Intra-arterial infusion of BK increases vascular release of F2- isoprostanes, markers of oxidative stress, BK infusions also increase net release of the inflammatory cytokine interleukin-6 (IL-6). Preliminary data raise the possibility that activation of the endogenous kallikrein-kinin system during dialysis could promote inflammation in individuals with chronic kidney disease who are treated with an ACE inhibitor.

Cardiopulmonary bypass activates the endogenous kallikrein-kinin system and causes a systemic inflammatory response. Like hemodialysis, cardiopulmonary bypass activates the endogenous kallikrein-kinin system, increasing BK concentrations. In smokers, who like hemodialysis patients exhibit endothelial dysfunction, the t-PA response to BK was attenuated during cardiopulmonary bypass.

ACE inhibition enhances fibrinolysis and decreases inflammation following cardiopulmonary bypass. The short-term effect of both ACE inhibition and angiotensin II type 1 (AT1) receptors on markers of fibrinolysis and inflammation during dialysis are currently being studied.

Circulating BK concentrations are increased during hemodialysis in individuals treated with an ACE inhibitors compared to those treated with an AT1 receptor blocker.

Bradykinin receptor blockade and the fibrinolytic and inflammatory response to hemodialysis. It is hypothesized that subjects with CAD, the t-PA response to hemodialysis will be blunted compared to that measured in subjects without evidence of CAD, whereas the inflammatory response wil be similar or enhanced.


Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 78 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Health Services Research
Official Title: Genes, Fibrinolysis and Endothelial Dysfunction- Dialysis Aim 3
Study Start Date : January 2010
Actual Primary Completion Date : June 2015
Actual Study Completion Date : June 2015

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Active Comparator: Valsartan
80 mg of valsartan (ARB) taken orally on a daily basis for 1 week followed by 160 mg of valsartan taken orally on a daily basis for 18 months
Drug: valsartan (ARB)
Other Name: Diovan

Active Comparator: Ramipril
2.5 mg of ramipril (ACE inhibitor) taken orally on a daily basis for 1 week followed by 5 mg of ramipril taken orally on a daily basis for 18 months
Drug: ramipril (ACE inhibitor)
Other Name: Altace

Placebo Comparator: Placebo
matching placebo taken orally on a daily basis for 1 week followed by matching placebo taken orally on a daily basis for 18 months
Drug: Placebo
Other Name: Inactive pill




Primary Outcome Measures :
  1. Interleukin-6 (IL-6) [ Time Frame: baseline and 18 months ]
    IL-6 is a sensitive laboratory assay for serum levels of interleukin-6, which is a pro-inflammatory cytokine used to evaluate the inflammatory response.



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Age 18 years or older
  • On thrice weekly chronic hemodialysis for at least 6 months
  • Clinically stable, adequately dialyzed [single-pool Kt/V > 1.2 or Urea Reduction Ratio (URR) > 65%] thrice weekly, with polysulphone membrane for at least 3 consecutive months prior to study

Exclusion Criteria:

  • History of functional transplant less than 6 months prior to study
  • Use of immunosuppressive drugs within 1 month prior to study
  • History of active connective tissue disease
  • History of acute infectious disease within one month prior to study
  • AIDS (HIV seropositivity is not an exclusion criteria)
  • History of myocardial infarction or cerebrovascular event within 3 months
  • Advanced liver disease
  • Gastrointestinal dysfunction requiring parental nutrition
  • Active malignancy excluding basal cell carcinoma of the skin
  • History of ACE inhibitor-associated cough (intolerable) or angioedema
  • Ejection fraction less than 30%
  • Inability to discontinue ACE inhibitor or ARB
  • Predialysis potassium repeatedly higher than 6.0 mmol/L (confirmed on a repeated blood draw)
  • Anticipated live donor kidney transplant
  • Pregnancy or breast-feeding
  • History of poor adherence to hemodialysis or medical regimen
  • Inability to provide consent

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 ClinicalTrials.gov identifier (NCT number): NCT00878969


Locations
United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
University of Washington
National Heart, Lung, and Blood Institute (NHLBI)
Investigators
Principal Investigator: Nancy J Brown, MD Vanderbilt University Medical Center
Principal Investigator: Talat A Ikilzer, MD Vanderbilt University Medical Center
Principal Investigator: Jonathan Himmelfarb, MD University of Washington

Responsible Party: Alp Ikizler, Professor, Vanderbilt University
ClinicalTrials.gov Identifier: NCT00878969     History of Changes
Other Study ID Numbers: Fibrinolysis in Dialysis Aim 3
R01HL065193-08A2 ( U.S. NIH Grant/Contract )
First Posted: April 9, 2009    Key Record Dates
Results First Posted: February 15, 2016
Last Update Posted: February 15, 2016
Last Verified: January 2016

Keywords provided by Alp Ikizler, Vanderbilt University:
Hemodialysis
fibrinolysis
oxidative stress
systemic inflammatory reaction
endothelial dysfunction
carotid intima media thickness (IMT
angiotensin receptor blockade
angiotensin converting enzyme inhibition

Additional relevant MeSH terms:
Valsartan
Ramipril
Angiotensin-Converting Enzyme Inhibitors
Antihypertensive Agents
Angiotensin II Type 1 Receptor Blockers
Angiotensin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action
Protease Inhibitors
Enzyme Inhibitors