Effects of Exercise and Improved Nitric Oxide Bioavailability on Arteriovenous Fistula Maturation

Not Applicable

Terminated

Brief Summary: This project will examine if enhancing Nitric Oxide (NO) bioavailability increases the rates of arteriovenous fistula (AVF) maturation in end stage renal disease patients requiring vascular access for hemodialysis. To enhance NO bioavailability the study team will utilize a program of forearm exercise training, application of nitroglycerin ointment or both. Goals of this study are (A) to measure if recruited subjects can tolerate the intervention protocols, and determine if dependent variable measures, including surgery outcome, and measurement of physiologic and biologic markers, can be obtained; (B) To measure subject compliance and adherence rates for each of the intervention arms and testing visits; (C) To examine which intervention or combination of interventions demonstrates the strongest preliminary effects in order to estimate power for a pivotal intent to treat trial; and (D) explore group differences in clinical vascular markers and biologic markers in vein tissue.

Detailed Description: This project will examine if enhancing Nitric Oxide (NO) bioavailability increases the rates of arteriovenous fistula (AVF) maturation in end stage renal disease patients requiring vascular access for hemodialysis. To enhance NO bioavailability the study team will utilize a program of forearm exercise training, application of nitroglycerin ointment or both.

Following entry into the study, approximately 4 weeks prior to surgery subjects will undergo a series of non-invasive tests of vascular function in the arm of fistula creation. Following this vascular function testing, subjects will follow the intervention treatment for 4 weeks. After 4 weeks of intervention treatment and prior to surgery, the vascular function analysis will be repeated to determine if the interventions had an effect on arm vascular function. Surgery to create the AVF will follow the second vascular function analysis. A discard sample of the vein used to create the AVF and a blood sample will be collected during surgery to assess potential biologic differences between intervention groups. The interventions will be continued until 4 weeks following surgery. Subjects will be followed to determine if the AVF matured and was successfully used for dialysis.

Recruitment & Eligibility

Inclusion Criteria

Life expectancy of at least 6 months
Chronic kidney disease with anticipated start of hemodialysis within six months or current hemodialysis dependence.
Ability to understand and comply with the requirements of the entire study and communicate with the study team.
Written informed consent using a document that has been approved by the Duke Human Institutional Review Board.
If female and of childbearing potential (premenopausal and not surgically sterile) must have a negative pregnancy test and be willing to use contraception until completion of 8 weeks of intervention. This will include abstinence, barrier methods, hormones, or intra-uterine device.

Exclusion Criteria

Patients currently on medication that is contraindicated with nitropaste, including isosorbide nitrate therapy, nitroglycerin, minoxidil, or PDE inhibitors (i.e. Sildenafil).
Patients with a diastolic blood pressure below 65 or a systolic blood pressure below 90.
Patients with a history of illicit drug use in the previous 5 years.
Patients who would require AVF placement before completion of the initial 4 weeks of intervention therapy
Patients who are otherwise are not suitable for 8 weeks of handgrip training or nitropaste therapy.
Patients under the 18 of age are not eligible for nitropaste interventions

Arm && Interventions

Group	Intervention	Description
Combined handgrip training /Nitroglycerin ointment group	Nitroglycerin ointment	Perform isometric handgrip exercises for 15 minutes twice each day for a total of 30 minutes and apply 15mg of nitroglycerin ointment to the back of the hand of the surgical arm nightly
Nitroglycerin ointment group	Nitroglycerin ointment	Apply 15mg of nitroglycerin ointment to the back of the hand of the surgical arm nightly
Combined handgrip training /Nitroglycerin ointment group	Handgrip training	Perform isometric handgrip exercises for 15 minutes twice each day for a total of 30 minutes and apply 15mg of nitroglycerin ointment to the back of the hand of the surgical arm nightly
Handgrip training group	Handgrip training	Perform isometric handgrip exercises for 15 minutes twice per day for a total of 30 minutes

Primary Outcome Measures

Name	Time	Method
Count of Participants With Mature Arteriovenous Fistula (AVF)	3 month post surgery to create AVF	Use of AVF for dialysis for dialysis dependent participants, or fistula deemed mature based on physical exam in predialysis participants (diameter \>6 mm, blood flow \>600 ml by ultrasound or estimated by physical exam).

Secondary Outcome Measures

Name	Time	Method
Count of Participants Using Their AVF for Dialysis	12 months post surgery	Successful use of AVF at 12 months in dialysis dependent patients. Not relevant in participants that are predialysis or that discontinue dialysis prior to AVF use.
Count of Participants With a Patent Fistula	3 months post surgery	Determination that AVF is patent (has blood flow, no occlusion).

Locations (1): Duke University Health System
🇺🇸
Durham, North Carolina, United States