Physiologic assessment of moderate coronary lesions: a step towards complete revascularization in coronary artery bypass grafting.

Abstract

An accurate diagnostic assessment of coronary artery disease is crucial for patients undergoing coronary artery bypass grafting (CABG). Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) to guide complete revascularization have not been adequately studied in patients prior to CABG. We compared an anatomic to a physiologic assessment of moderate coronary lesions (40-70% stenosis) in patients referred for CABG. We retrospectively reviewed 109 medical records of patients who underwent CABG at Tulane Medical Center from 2014 to 2016. Patients were divided into an FFR/iFR-guided and an angiography-guided group. Clinical characteristics, procedural outcomes, and clinical outcomes for the two groups were compared over an 18-month follow-up period. There were significantly higher rates of three-vessel anastomoses (85.7% vs. 74.7%, P<0.05) and venous grafting (85.7% vs. 76.8%, P<0.05) in the FFR/iFR group. The FFR/iFR group had a lower rate of grafts placed to the left anterior descending artery (LAD) distribution than the angiography group (7.1% vs. 29.5%, P<0.05). The FFR/iFR group had a higher rate of grafts placed to the left circumflex (LCx) artery distribution than the angiography group (28.6% vs. 9.5%, P<0.05). We observed a trend toward reduction in major adverse cardiac events (MACEs) (7.1% vs. 11.6%, P=0.369) and angina (0.0% vs. 6.3%, P=0.429) in the FFR/iFR group compared to the angiography group over 18 months. Physiologic assessment of coronary lesions can effectively guide complete revascularization in patients undergoing CABG. Moreover, FFR/iFR-guided CABG was associated with significantly higher rates of three-vessel anastomoses, venous grafting, and graft distribution to the circumflex system.