Author + information
- Received May 1, 1995
- Revision received August 24, 1995
- Accepted August 31, 1995
- Published online February 1, 1996.
- Olivier Gurné, MD*,
- Patrick Chenu, MD,
- Michel Buche, MD,
- Jacques Jamart, MD,
- Yves Louagie, MD,
- Philippe Eucher, MD,
- Baudouin Marchandise, MD and
- Erwin Schroeder, MD
- ↵*Address for correspondence: Dr. Olivier Gurné, Department of Cardiology, Mont-Godinne Hospital, 5530 Yvoir, Belgium.
Objectives. The free epigastric artery bypass graft is proposed as an alternative conduit to the saphenous vein graft, known for its high rate of attrition. The aim of our study was to assess its endothelial function in vivo.
Background. The endothelium of arterial bypass grafts plays a role in both the performance and the patency of such grafts.
Methods. We studied 73 epigastric grafts early (mean ± SD 10 ± 3 days) and 36 late (12 ± 5 months) after coronary bypass surgery with quantitative angiography at rest, after 2 min of atrial pacing (130 beats/min) and after injection of isosorbide dinitrate (1 to 2 mg) into the graft.
Results. At rest, mean epigastric graft diameter was lower in the late than in the early postoperative period (2.26 ± 0.39 vs. 2.61 ± 0.49 mm, p < 0.001). Early after operation, epigastric grafts with a small or an intermediate runoff, but not those with a large runoff, were capable of vasodilation with nitrates (+0.09 ± 0.10 mm). Late after operation, vasodilation after administration of isosorbide dinitrate was similar in epigastric grafts with a large runoff and in those with a small or intermediate runoff (+0.23 ± 0.09 vs. +0.23 ± 0.18 mm). Significant vasodilation during pacing was observed late (+4 ± 9%, p < 0.01) but not early postoperatively, except in a subset of patients with grafts capable of vasodilation after nitrates. A correlation between the response to nitrates and the response during pacing was observed early (r = 0.579, p < 0.001) and late postoperatively (r = 0.530, p = 0.02).
Conclusions. Flow-mediated vasodilation during pacing was observed in most epigastric grafts late, but not early, after operation. This endothelium-dependent dilation was correlated with the importance of the vasodilation observed with nitrates (endothelium-independent), which was related to the importance of the runoff only in the early postoperative period. The ability of epigastric grafts late postoperatively to dynamically adapt their dimensions to an acute increase in demand could contribute to the good functional results of this new alternative arterial graft.
This study was supported by a grant from the Bekales Foundation (Fond National Recherche Scientifique, Brussels) and from the Fond de Développement Scientifique (FDS, University of Louvain, Louvain), Belgium.
- Received May 1, 1995.
- Revision received August 24, 1995.
- Accepted August 31, 1995.