Endothelial Function in Lower Extremity Bypass Grafts
This study will determine whether or not saphenous vein [arterial] bypass grafts in the leg relax in response to increases in blood flow.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
|Official Title:||Endothelial Function in Lower Extremity Bypass Grafts|
- Change from baseline in saphenous vein bypass graft vasodilation [ Time Frame: pre/post ischemic stimulus ] [ Designated as safety issue: No ]
|Study Start Date:||April 2006|
|Study Completion Date:||December 2009|
|Primary Completion Date:||December 2009 (Final data collection date for primary outcome measure)|
ultrasound imaging of saphenous vein bypass graft following an ischemic stimulus, administration of sublingual nitroglycerin and intravenous administration of L-NMMA.
Drug: L-N^G monomethyl arginine (L-NMMA)
L-NMMA was infused at a dose of 1 mg/kg over 10 minutes to competitively inhibit the production of nitric oxide. Ultrasound imaging of the saphenous vein [arterial] bypass at baseline, and following an ischemic stimulus, administration of sublingual nitroglycerin, and intravenous administration of L-NMMA.
Subjects who have undergone saphenous vein [arterial] bypass grafts from the femoral to above-knee popliteal artery will undergo ultrasound imaging at rest, and again after 5 minutes of blood pressure cuff occlusion of the calf. (at 1 minute and 15 minutes) Subjects will then be given sub-lingual nitroglycerin, and repeat ultrasound will be performed 3 minutes later. Following 10 minutes of rest, subjects will be given intravenous L-NMMA, a specific nitric oxide inhibitor, to help determine the responsible agent of the vein graft flow mediated dilation.
|United States, Massachusetts|
|Brigham and Women's Hospital|
|Boston, Massachusetts, United States, 02115|
|Principal Investigator:||Joshua A. Beckman, M.D.||Brigham and Women's Hospital|