Predictors of discordance between fractional flow reserve and instantaneous wave-free ratio in the real world

Invasive physiologic variables such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are used in clinical practice to assess the functional significance of epicardial coronary stenosis and guide the management. However, these two variables may show discrepancies when binary cut-offs are used to decide for revascularization strategy. We investigated the clinical characteristics of lesions with discordance between iFR and FFR. 256 vessels (220 patients mean age 61 ± 12, 77% males) with available pre-intervention FFR and iFR values were included in the study. The vessels were classified according to FFR and iFR into concordant normal (Group 1 [n = 112]; FFR > 0.8 and iFR > 0.89); discordant with abnormal FFR and normal iFR (Group 2 [n = 12); FFR 0.89); discordant with normal FFR and abnormal iFR (Group 3 [n = 43], FFR > 0.8 and iFR