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Fractional flow reserve (FFR) is an established method for assessing functional myocardial ischemia. Recently, the resting full-cycle ratio (RFR) has been introduced as a non-hyperemic index of functional coronary stenosis. However, the effects of clinical characteristics on discordance between RFR and FFR have not been fully evaluated. We aimed to identify clinical characteristics that influence FFR-RFR concordance.We included 410 patients with 573 intermediate coronary lesions who underwent clinically indicated invasive coronary angiography, as well as assessments of FFR and RFR. Receiver-operating characteristic (ROC) curves were created to assess the optimal cut-off values of RFR for predicting FFR ≤0.80.RFR exhibited a strong correlation with FFR (r = 0.66, p 0.0001). ROC analysis identified an optimal RFR cut-off value of 0.92 for categorization based on an FFR cut-off value of 0.8. The discordance of FFR0.8 and RFR ≤0.92 (high FFR/low RFR) was observed in 112 lesions (20.9%), whereas the discordance of FFR ≤0.8 and RFR0.92 (low FFR/high RFR) was observed in 35 lesions (6.5%). Higher rate of hemodialysis and lower hemoglobin levels were observed in the high FFR/low RFR group. Multivariate analyses identified female sex, left anterior descending artery (LAD) lesions, and hemodialysis as significant predictors of high FFR/low RFR. Conversely, body surface area and non-LAD lesions were significantly associated with low FFR/high RFR. Hemodialysis [odds ratio (OR): 2.41, 95% confidence interval (CI) 1.31-4.41; p = 0.005] and LAD lesions (OR: 1.86, 95% CI: 1.25-2.79; p = 0.002) were identified as independent predictors of overall FFR-RFR discordance.RFR exhibited good diagnostic performance in the identification of functionally significant stenosis. However, RFR may overestimate functional severity in patients undergoing hemodialysis or in those with LAD lesions. Further prospective trials are required to demonstrate the non-inferiority of RFR to FFR.

Endovascular treatment (EVT) for femoropopliteal artery disease is common in clinical practice. However, little is known about its prognostic factors, causes of death, and long-term clinical outcomes.Two hundred eighty-five consecutive patients (mean age, 72±8 years, 73% men) undergoing their first EVT for de-novo femoropopliteal artery disease from 2009 to 2018 were studied. Patients were divided in two groups according to the presence of critical limb ischemia (CLI). We evaluated the incidence of major adverse limb events (MALE) including clinically driven target vessel revascularization and target limb major amputation, and all-cause death.The procedure was successful in 97.9% of cases. The non-CLI group comprised 205 patients (72%), and the CLI group comprised 80 patients (28%). The CLI group exhibited higher high-sensitivity C-reactive protein (hs-CRP) levels and a higher rate of hemodialysis than the non-CLI group. During the median follow-up period of 3.5 years, there were 62 deaths (21.8%) including cardiovascular (32.3%), infection (32,3%), and malignancy-related (22.6%) deaths. Kaplan-Meier analysis revealed that the CLI group had a significantly higher incidence of MALE and all-cause death (log-rank, both p0.001, respectively). The leading causes of death in the CLI group were cardiovascular- and infection-related death; the leading cause of death in the non-CLI group was malignancy-related. On multivariate Cox hazard analysis, hemodialysis, TASC II classification C/D lesions, and CLI were significant predictors of MALE (p0.001, p=0.005, and p=0.012, respectively). Hemodialysis, age, higher hs-CRP levels, and CLI were significant predictors of all-cause death (p0.001, p=0.003, p=0.009, and p=0.021, respectively).Although EVT for femoropopliteal artery disease appears feasible with a high rate of procedural success, a high incidence of MALE and all-cause death was observed. Further studies are needed to improve the outcomes in patients with CLI.