Relationship between resting full‐cycle ratio and fractional flow reserve in assessments of coronary stenosis severity

Abstract

Aim: Comparisons between the resting full-cycle ratio (RFR), a new physiological resting index, and fractional flow reserve (FFR) in terms of prognostic value are limited. We aimed to identify the prognostic value of concordance between RFR and FFR and to determine the stability of measured RFR. Methods and Results: We measured FFR and RFR in 161 coronary arteries of 119 patients and classified the data using known cutoffs for FFR (≤0.80) and RFR (≤0.89) into groups; high FFR and high RFR (high FFR/low RFR) group, high FFR and low RFR (high FFR/low RFR) group, low FFR and high RFR (low FFR/high RFR) group, and low FFR and low RFR (low FFR/low RFR) group. The concordance rates in these groups were 42.2% (68/161), 4.4% (7/161), 14.3% (23/161), and 39.1% (63/161), respectively. The concordance between FFR and RFR was 81.4%. The prevalence of females was significantly higher, values for hemoglobin values were significantly lower, and average E/E 0 (an index of left ventricular (LV) diastolic function by echocardiography) was significantly higher in high FFR/low RFR group than in low FFR/high RFR group (p = .008, .050, and .028, respectively). Conclusions: The RFR and FFR values consistently agreed. Female, anemia, and LV diastolic dysfunction may be related to the difference of discordance between high FFR/low RFR and low FFR/high RFR.

Usefulness of the Hybrid RFR-FFR Approach: Results of a Prospective and Multicenter Analysis of Diagnostic Agreement between RFR and FFR—The RECOPA (REsting Full-Cycle Ratio Comparation versus Fractional Flow Reserve (A Prospective Validation)) Study

“…On establishing a comparative dichotomous evaluation of the previously recommended thresholds corresponding to RFR (≤0.89) and FFR (≤0.80), as the main objective of our study, moderate values were obtained for sensitivity (76%), specificity (80%), PPV (68%), and NPV (86%). us, the diagnostic accuracy or agreement obtained was only 79%, though this is consistent with the findings of Muroya et al [19] (81%), who also conducted a dichotomous evaluation of RFR and FFR with the recommended values.…”

“…Finally, the percentage of stenoses ≥70% was limited, which reduces validity in reference to angiographically significant lesions. However, the inclusion of lesions ≥70% was greater than that in previous studies [9,19,21].…”

“…This is because the inclusion criteria used were scantly restrictive, allowing the inclusion of patients with ischemic heart disease encompassing the entire spectrum of situations in which invasive physiological studies are used in routine clinical practice. Furthermore, in contrast to most published studies [ 9 , 19 , 21 ] that almost exclusively evaluate intermediate lesions in stable patients, our study included a modest percentage (19.5%) of lesions ≥70%. The lesions included in this range of stenoses corresponded mainly to patients referred to the hemodynamics laboratory without prior ischemia evaluation and patients with multivessel disease amenable to surgical revascularization.…”

“…Although Lee et al [9] reported excellent agreement among a number of resting indices (RFR, iFR, and diastolic pressure ratio) and between these indices and FFR, the data were obtained indirectly from information from other studies [15][16][17][18]. To date, only two small studies have evaluated the degree of agreement between RFR and FFR [19,20]. For this reason, the RECOPA prospective, multicenter validation study was specifically designed to assess agreement between the recommended cut-off values for RFR and FFR in different clinical scenarios with a large sample of patients and thus could provide valuable information.…”

Acetylcholine provocation test with resting full-cycle ratio, coronary flow reserve, and index of microcirculatory resistance give definite answers and improve health-related quality of life

“…During the second consultation, the working diagnosis of ischemia and no obstructive coronary artery disease (INOCA) was provided. The following procedures were planned: resting full-cycle ratio (RFR), coronary flow reserve (CFR), index of microcirculatory resistance (IMR) as well as a provocative test with acetylcholine [3]. Parameters were assessed using CoroFlow software (Coroventis, Uppsala, Sweden) and the pressure-temperature sensor guidewire PressureWire X (Abbott Laboratories, Abbott Park, IL).…”