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The Graft Imaging to Improve Patency (GRIIP) clinical trial results
Steve K Singh1, Nimesh D Desai, Genta Chikazawa
1Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. stephen.fremes@sunnybrook.ca
Insights
Routine intraoperative graft assessment using imaging did not significantly reduce graft occlusion after coronary artery bypass grafting. Saphenous vein graft failure remains high despite current practices and surveillance.
Area of Science:
- Cardiovascular Surgery
- Medical Imaging
- Clinical Trials
Background:
- Coronary artery bypass grafting (CABG) outcomes are influenced by graft patency.
- Intraoperative assessment aims to optimize graft quality and reduce early failure.
- The effectiveness of routine intraoperative graft assessment in improving long-term outcomes remains under investigation.
Purpose of the Study:
- To determine if intraoperative graft assessment with revision criteria reduces graft occlusion or major adverse cardiac events one year after CABG.
- To evaluate the impact of enhanced intraoperative graft surveillance on patient outcomes.
Main Methods:
- A single-center, randomized, single-blinded, controlled trial.
- Patients were randomized to either intraoperative graft assessment (indocyanine-green angiography, transit-time flowmetry) with revision or standard management.
- Follow-up angiography was performed at one year.
Main Results:
- No significant difference in graft occlusion rates (30.9% vs. 28.9%) or major adverse cardiac events (7.7% vs. 7.7%) at one year between groups.
- The incidence of saphenous vein graft occlusion was high in both the imaging and control groups.
- Intraoperative assessment was safe, with no significant increase in operative times.
Conclusions:
- Routine intraoperative graft assessment does not significantly decrease graft occlusion one year post-CABG.
- Saphenous vein graft failure rates remain high, indicating a need for improved strategies.
- Current intraoperative surveillance methods may not be sufficient to overcome inherent graft issues.
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.
