The Graft Imaging to Improve Patency (GRIIP) clinical trial results.
OBJECTIVE
This trial aimed to determine whether intraoperative graft assessment with criteria for graft revision would decrease the proportion of patients with 1 or more graft occlusions or stenoses or major adverse cardiac events 1 year after coronary artery bypass grafting.


METHODS
A single-center, randomized, single-blinded, controlled clinical trial was designed. Patients were randomized to either of 2 groups: intraoperative graft patency assessment using indocyanine-green fluorescent angiography and transit-time flowmetry, with graft revision according to a priori criteria (imaging group), or standard intraoperative management (control group). Patients underwent follow-up angiography at 1 year.


RESULTS
Between September 2005 and August 2008, 156 patients undergoing isolated coronary bypass grafting were enrolled (imaging, n = 78; control, n = 78). Demographic and angiographic characteristics were similar between groups. Operative, crossclamp, and cardiopulmonary bypass times were all nonsignificantly longer in the imaging arm. The number of grafts per patients was similar (imaging, 3.0 +/- 0.7; control, 3.0 +/- 0.7). The frequency of major adverse cardiac events (death, myocardial infarction, repeat revascularization) was not different between groups at 1 year postoperatively (imaging, 7.7%; control, 7.7%). One-year angiography was performed in 107 patients (imaging, 55 patients/160 grafts; control, 52 patients/152 grafts). The proportion of patients with 1 graft occlusion or more was comparable in the imaging (30.9%) and control (28.9%) groups (relative risk [95% confidence interval], 1.1 [0.6-1.9]; P = .82), as were other graft patency end points. The incidence of saphenous vein graft occlusion was high in both groups.


CONCLUSIONS
Routine intraoperative graft assessment is safe but does not lead to a marked reduction in graft occlusion 1-year after bypass grafting. The incidence of saphenous vein graft failure remains high despite contemporary practice and routine intraoperative graft surveillance.
Singh
Steve K
SK
Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. stephen.fremes@sunnybrook.ca
Desai
Nimesh D
ND
Chikazawa
Genta
G
Tsuneyoshi
Hiroshi
H
Vincent
Jessica
J
Zagorski
Brandon M
BM
Pen
Visal
V
Moussa
Fuad
F
Cohen
Gideon N
GN
Christakis
George T
GT
Fremes
Stephen E
SE
D000328:Adult; D001026:Coronary Artery Bypass; D005451:Fluorescein Angiography; D005471:Fluoroscopy; D006083:Graft Occlusion, Vascular / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D007208:Indocyanine Green; D007432:Intraoperative Period; D012212:Rheology / Q000379:methods; D012501:Saphenous Vein / Q000637:transplantation; D016037:Single-Blind Method; D014654:Vascular Patency
D007208:Indocyanine Green