The Graft Imaging to Improve Patency (GRIIP) clinical trial results

Singh, Steve K.; Desai, Nimesh D.; Chikazawa, Genta; Tsuneyoshi, Hiroshi; Vincent, Jessica; Zagorski, Brandon M.; Pen, Visal; Moussa, Fuad; Cohen, Gideon N.; Christakis, George T.; Fremes, Stephen E.

doi:10.1016/j.jtcvs.2009.09.048

« Previous Next »The Journal of Thoracic and Cardiovascular Surgery
Volume 139, Issue 2 , Pages 294-301.e1, February 2010

The Graft Imaging to Improve Patency (GRIIP) clinical trial results

Read at the Eighty-ninth Annual Meeting of The American Association for Thoracic Surgery (C. Walton Lillehei Resident Forum), Boston, Massachusetts, May 9–13, 2009.

Steve K. Singh, MD, MSc
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
- Address for reprints: Steve K. Singh, MD, MSc, c/o Stephen E. Fremes, MD, MSc, 2075 Bayview Ave, Suite H410, Toronto, Ontario, Canada M4 N 3M5.
Nimesh D. Desai, MD, PhD
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Genta Chikazawa, MD, PhD
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Hiroshi Tsuneyoshi, MD, PhD
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Jessica Vincent, BSc
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Brandon M. Zagorski, MSc
- Institute for Clinical Evaluative Science, Toronto, Ontario, Canada
Visal Pen, MD
- Division of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Fuad Moussa, MD, MSc
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Gideon N. Cohen, MD, PhD
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
George T. Christakis, MD, MSc
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Stephen E. Fremes, MD, MSc
- Division of Cardiac and Vascular Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
- Institute for Clinical Evaluative Science, Toronto, Ontario, Canada

Received 8 May 2009; received in revised form 8 September 2009; accepted 28 September 2009. published online 14 December 2009.

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.

CTSNet classification: 23.2, 23.1, 23.2

Abbreviations and Acronyms: CABG, coronary artery bypass graft, CPB, cardiopulmonary bypass, GRIIP trial, Graft Imaging to Improve Patency trial, ICG, indocyanine green, MACE, major adverse clinical event, TTF, transit-time ultrasound flowmetry