Effects of guiding catheter on franctional flow reserve and non-hyperemic pressure ratios for the assessment of coronary artery stenoses

Abstract

Abstract Aims Non-hyperemic pressure-derived Indexes (NHPI) provide diagnostic efficacy equivalent to fractional flow reserve (FFR) to guide percutaneous coronary interventions. In the Disengage (Determination of Fractional Flow Reserve in Intermediate Coronary Stenosis With Guiding Catheter Disengagement) registry, selective decannulation of the guiding catheter (GC) within the coronary ostium during FFR assessment was associated with a significant overall decrease in FFR, particularly when the stenosis was located in the proximal and middle coronary segments. So far it is unclear what influence the selective cannulation of the catheter in the coronary artery ostium has on the NHPI. This prospective registry aimed to evaluate the influence of GC engagement within the coronary ostium on FFR and NHPI values. Methods and results In the DISENGAGE@Rest (Determination of Fractional Flow Reserve in Intermediate Coronary Stenosis With Guiding Catheter Disengagement) 133 patients with 164 intermediate coronary artery stenoses (40-90%) were enrolled. We evaluated: 1) the impact of GC engagement within the coronary ostium on FFR and NHPI values; 2) implications for clinical decision making; 3) the relationship between coronary physiology indices and study site (proximal, middle and distal coronary segments). Disengagement of GC was associated with a significant decrease in FFR (FFReng, 0.85±0.07 vs. FFRdis, 0.83±0.07; p< .001), Pd/Pa (Pd/Paeng, 0.94±0.05 vs. Pd/Padis, 0.93±0.05; p< .001) and RFR values (RFReng, 0.91±0.07 vs. RFRdis, 0.90±0.07; p= .018). This significant decrease in invasive physiologic indexes was driven by a significant increase in mean Pa value (Pa eng, 93±15 mm Hg vs. Pa dis, 97±15 for FFR; P < .001; Pa eng, 94±15 mm Hg vs Pa dis, 96±15 for Pd/Pa; P < .001 Pa eng, 95±15 mm Hg vs Pa dis, 97±15 for RFR; P < .001), without changes in mean Pd value. In 24 (15%), 12 (7%) and 17 (10%) lesions, FFR, RFR and Pd/Pa values, respectively, shifted below the cut-off point after GC disengagement with changes in clinical decision-making. There was a significant FFR change, but no NHPI, across different segments (ΔFFReng–FFRdis proximal 0.04±0.03 vs. ΔFFReng–FFRdis middle 0.02±0.02 vs. ΔFFReng–FFRdis distal 0.03±0.04; p= .018). Conclusions The results confirm a significant overall decrease in FFR after GC disengagement and extend this to Pd/Pa and RFR. In case of proximal coronary artery disease, GC disengagement should be performed in order not to underestimate the hemodynamic significance of the lesion under examination.