459 PREOPERATIVE ANGIOGRAPHY-DERIVED FRACTIONAL FLOW RESERVE MAY PREDICT BYPASS GRAFT OCCLUSION AND DISEASE PROGRESSION AT MID-TERM FOLLOW-UP

Abstract

Abstract Background Coronary artery bypass grafting (CABG) is the most common revascularization mode for patients with multivessel coronary artery disease (CAD). Despite substantial improvements in the outcome of patients undergoing CABG surgery, graft occlusion remains a weakness of this procedure and has been associated with competitive flow of native coronary arteries. Our study aims to assess graft occlusion and the progression of CAD in native vessels after CABG surgery at follow-up with coronary CT angiography (CCTA), and their relationship with angiography-derived vessel-fractional flow reserve (vFFR) performed before surgery. Methods We retrospectively selected patients from two European institutions, treated with CABG between January 2006 and December 2018, who underwent follow-up with CCTA. All patients had a preoperative angiogram performed before CABG. Results In 171 consecutive patients, serial preoperative angiograms were suitable for vFFR analysis of 298 grafted and 59 non-grafted vessels. Table 1 shows clinical and main procedural characteristics. Preoperative vFFR was assessed in 131 left anterior descending arteries (LAD), 132 left circumflex arteries (LCX) and 94 right coronary arteries (RCA) and was <0.80 in 255 of 298 bypassed vessels. Graft occlusion was observed at CCTA in 28 of 298 grafts. The median preoperative vFFR value of native coronaries was higher in occluded compared to patent grafts (0.75 vs. 0.60, p<0.001) (Figure 1) and was associated with graft type. The best vFFR cut-off to predict graft occlusion was 0.67. The functional CAD progression was higher in grafted compared to non-grafted vessels (89.6% vs 47.5% p < 0.001) and pre-CABG vFFR predicted disease progression of grafted native vessels (AUC=0.83) (Figure 2). Conclusions Preoperative vFFR derived from invasive coronary angiography was able to predict graft occlusion and CAD progression of grafted coronary arteries.