Endothelial Hyperpolarization in Humans

• ClinicalTrials.gov Identifier: NCT00166166
• Recruitment Status: Terminated
• First Posted: September 14, 2005
• Results First Posted: May 13, 2015
• Last Update Posted: August 15, 2018
• Sponsor: Emory University
• Collaborator: National Heart, Lung, and Blood Institute (NHLBI)
• Information provided by (Responsible Party): Arshed A. Quyyumi, Emory University

• Study Type: Interventional
• Study Design: Allocation: Non-Randomized; Intervention Model: Single Group Assignment; Masking: None (Open Label); Primary Purpose: Diagnostic
• Condition: Hyperlipidemia
• Interventions: Drug: Tetraethylammonium (TEA); Drug: L-NG-monomethyl Arginine (L-NMMA); Drug: Bradykinin; Drug: Sodium nitroprusside; Drug: Acetylcholine; Drug: Saline; Drug: Fluconazole
• Enrollment: 174

Participant Flow

Recruitment Details
Pre-assignment Details

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine
Period Title: Overall Study
Started	103	71
Completed	103	71
Not Completed	0	0

Baseline Characteristics

Arm/Group Title		Healthy Controls	Risk Factors	Total
Arm/Group Description		Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine	Total of all reporting groups
Overall Number of Baseline Participants		103	71	174
Baseline Analysis Population Description		Baseline characteristics represent subjects that completed the study.
Age, Continuous; Mean (Standard Deviation); Unit of measure: Years
	Number Analyzed	103 participants	71 participants	174 participants
		34 (11)	46 (12)	40 (12)
Sex: Female, Male; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	103 participants	71 participants	174 participants
	Female	49 47.6%	32 45.1%	81 46.6%
	Male	54 52.4%	39 54.9%	93 53.4%

Outcome Measures

1. Primary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After Tetraethylammonium (TEA) Administration
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph at rest and after administration of tetraethylammonium (TEA). Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference from baseline FBF and after TEA administration.
Time Frame	Baseline, 5 minutes

Outcome Measure Data

Analysis Population Description

Only 62 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and Tetraethylammonium (TEA).	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and Tetraethylammonium (TEA)
Overall Number of Participants Analyzed	37	25
Mean (Standard Error); Unit of Measure: percent change
	-18 (16)	-24 (13)

2. Primary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After Administration of L-NG-monomethyl Arginine (L-NMMA)
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph after administration of L-NG-monomethyl Arginine (L-NMMA). Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference in FBF from baseline and after L-NMMA administration.
Time Frame	Baseline, 5 minutes

Outcome Measure Data

Analysis Population Description

Only 62 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and L-NG-monomethyl Arginine (L-NMMA)	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and L-NG-monomethyl Arginine (L-NMMA)
Overall Number of Participants Analyzed	37	25
Mean (Standard Error); Unit of Measure: percent change
	-29 (17)	-23 (15)

3. Secondary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After Administration of L-NG-monomethyl Arginine (L-NMMA) and Tetraethylammonium (TEA)
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph after administration of L-NG-monomethyl Arginine (L-NMMA) and Tetraethylammonium (TEA). Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference in FBF from after L-NMMA administration and after TEA administration.
Time Frame	5 minutes, 10 minutes

Outcome Measure Data

Analysis Population Description

Only 62 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and L-NG-monomethyl Arginine (L-NMMA)	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and L-NG-monomethyl Arginine (L-NMMA)
Overall Number of Participants Analyzed	37	25
Mean (Standard Error); Unit of Measure: percent change
	-38 (17)	-39 (17)

4. Secondary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After Fluconazole Administration
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph at rest and after administration of fluconazole. Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference from baseline FBF and after fluconazole administration.
Time Frame	Baseline, 5 minutes

Outcome Measure Data

Analysis Population Description

Only 33 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and fluconazole.	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline (baseline) and fluconazole
Overall Number of Participants Analyzed	26	7
Mean (Standard Error); Unit of Measure: percent change
	-13 (16)	-17 (13)

5. Secondary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After L-NG-monomethyl Arginine (L-NMMA) and Fluconazole Administration
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph after L-NMMA administration and administration of fluconazole. Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference in FBF after L-NMMA administration and then fluconazole administration.
Time Frame	5 minutes, 10 minutes

Outcome Measure Data

Analysis Population Description

Only 15 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of L-NG-monomethyl Arginine (L-NMMA), and fluconazole	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of L-NG-monomethyl Arginine (L-NMMA) and fluconazole
Overall Number of Participants Analyzed	8	7
Mean (Standard Error); Unit of Measure: percent change
	-26 (22)	-26 (22)

6. Secondary Outcome

Title	Percent Change in Forearm Blood Flow (FBF) After Fluconazole and Tetraethylammonium (TEA) Administration
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph after administration of fluconazole and Tetraethylammonium (TEA) administration. Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed. Percent change is the difference from FBF after fluconazole administration and after Tetraethylammonium (TEA) administration.
Time Frame	5 minutes, 10 minutes

Outcome Measure Data

Analysis Population Description

Only 19 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of fluconazole and Tetraethylammonium (TEA)
Overall Number of Participants Analyzed	19
Mean (Standard Error); Unit of Measure: percent change
	-22 (23)

7. Secondary Outcome

Title	Forearm Blood Flow (FBF) After Sodium Nitroprusside Administration
Description	Simultaneous forearm blood flow (FBF) measurements were obtained in both arms using a dual-channel venous occlusion strain gauge plethysmograph after administration of sodium nitroprusside. Flow measurements were recorded for approximately 7 seconds, every 15 seconds up to eight times and a mean FBF value was computed.
Time Frame	5 minutes

Outcome Measure Data

Analysis Population Description

Only 80 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of sodium nitroprusside	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of sodium nitroprusside
Overall Number of Participants Analyzed	42	38
Mean (Standard Error); Unit of Measure: mL min^-1 * 100 mL^-1
	10.4 (4)	10.9 (5)

8. Secondary Outcome

Title	Change in Tissue Plasminogen Activator (t-PA) Release
Description	Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively. Change is the difference of t-PA at baseline and t-PA after bradykinin 400 ng/min
Time Frame	Baseline, 30 minutes

Outcome Measure Data

Analysis Population Description

Only 33 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of bradykinin
Overall Number of Participants Analyzed	33
Mean (Standard Error); Unit of Measure: ng/mL
	5.6 (0.8)

9. Secondary Outcome

Title	Change in Tissue Plasminogen Activator (t-PA) Release After Tetraethylammonium (TEA) and Bradykinin Administration
Description	Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively. Change is the difference of t-PA after Tetraethylammonium (TEA) and t-PA after bradykinin 400 ng/min
Time Frame	30 minutes, 60 minutes

Outcome Measure Data

Analysis Population Description

Only 18 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of bradykinin and Tetraethylammonium (TEA)
Overall Number of Participants Analyzed	18
Mean (Standard Error); Unit of Measure: ng/mL
	0.03 (0.7)

10. Secondary Outcome

Title	Change in Tissue Plasminogen Activator (t-PA) Release After Fluconazole and Bradykinin Administration
Description	Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively. Change is the difference of t-PA after fluconazole and t-PA after bradykinin 400 ng/min
Time Frame	30 minutes, 60 minutes

Outcome Measure Data

Analysis Population Description

Only 11 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of bradykinin and fluconazole
Overall Number of Participants Analyzed	11
Mean (Standard Error); Unit of Measure: ng/mL
	4.4 (1.4)

11. Secondary Outcome

Title	Change in Tissue Plasminogen Activator (t-PA) Release After Fluconazole, Tetraethylammonium (TEA), and Bradykinin Administration
Description	Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively. Change is the difference of t-PA after fluconazole and tetraethylammonium (TEA) and t-PA after bradykinin 400 ng/min
Time Frame	60 minutes, 90 minutes

Outcome Measure Data

Analysis Population Description

Only 10 of the original 174 subjects were treated for this portion of the study.

Arm/Group Title	Healthy Controls
Arm/Group Description:	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of bradykinin, fluconazole and tetraethylammonium (TEA)
Overall Number of Participants Analyzed	10
Mean (Standard Error); Unit of Measure: ng/mL
	1.6 (0.4)

Adverse Events

Time Frame	[Not Specified]
Adverse Event Reporting Description	[Not Specified]
Arm/Group Title	Healthy Controls	Risk Factors
Arm/Group Description	Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine	Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine
All-Cause Mortality
	Healthy Controls	Risk Factors
	Affected / at Risk (%)	Affected / at Risk (%)
Total	--/--	--/--
Serious Adverse Events
	Healthy Controls	Risk Factors
	Affected / at Risk (%)	Affected / at Risk (%)
Total	0/103 (0.00%)	0/71 (0.00%)
Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events	5%
	Healthy Controls	Risk Factors
	Affected / at Risk (%)	Affected / at Risk (%)
Total	0/103 (0.00%)	0/71 (0.00%)

Limitations and Caveats

Findings are limited to the forearm microcirculations, thus other vascular beds including conductance arteries warrant further investigation. Nevertheless, it is known that the contribution of EDHF is less in conductance vessels than in microvessels.

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

Results Point of Contact

• Name/Title: Dr. Arshed Quyyumi
• Organization: Emory University
• Phone: 404-727-3655
• EMail: aquyyum@emory.edu

Publications of Results:

Ozkor MA, Murrow JR, Rahman AM, Kavtaradze N, Lin J, Manatunga A, Quyyumi AA. Endothelium-derived hyperpolarizing factor determines resting and stimulated forearm vasodilator tone in health and in disease. Circulation. 2011 May 24;123(20):2244-53. doi: 10.1161/CIRCULATIONAHA.110.990317. Epub 2011 May 9.

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Ozkor MA, Hayek SS, Rahman AM, Murrow JR, Kavtaradze N, Lin J, Manatunga A, Quyyumi AA. Contribution of endothelium-derived hyperpolarizing factor to exercise-induced vasodilation in health and hypercholesterolemia. Vasc Med. 2015 Feb;20(1):14-22. doi: 10.1177/1358863X14565374. Epub 2015 Feb 3.

Rahman AM, Murrow JR, Ozkor MA, Kavtaradze N, Lin J, De Staercke C, Hooper WC, Manatunga A, Hayek S, Quyyumi AA. Endothelium-derived hyperpolarizing factor mediates bradykinin-stimulated tissue plasminogen activator release in humans. J Vasc Res. 2014;51(3):200-8. doi: 10.1159/000362666. Epub 2014 Jun 4.

Ozkor MA, Rahman AM, Murrow JR, Kavtaradze N, Lin J, Manatunga A, Hayek S, Quyyumi AA. Differences in vascular nitric oxide and endothelium-derived hyperpolarizing factor bioavailability in blacks and whites. Arterioscler Thromb Vasc Biol. 2014 Jun;34(6):1320-7. doi: 10.1161/ATVBAHA.113.303136. Epub 2014 Mar 27.

• Responsible Party: Arshed A. Quyyumi, Emory University
• ClinicalTrials.gov Identifier: NCT00166166
• Other Study ID Numbers: IRB00021886; 1R01HL079115-01 ( U.S. NIH Grant/Contract ); 0605-2002 ( Other Identifier: Other )
• First Submitted: September 13, 2005
• First Posted: September 14, 2005
• Results First Submitted: May 8, 2015
• Results First Posted: May 13, 2015
• Last Update Posted: August 15, 2018