{
  "abstract": "Background Intracoronary pressure wire measurements allow functional assessment of a coronary stenosis by quantifying the pressure gradient across the lesion ( figure 1). Fractional flow reserve (FFR) is the gold-standard intracoronary pressure wire method to assess the functional significance of a coronary stenosis but requires the administration of adenosine. However, resting full-cycle ratio (RFR) is a newer, non-hyperaemic alternative avoiding the unpleasant, transient side effects from adenosine. Current evidence suggests an RFR-FFR concordance of 79.8–95.3% but the limited number of studies restrict the reliability of RFR and its standalone use. This retrospective analysis aimed to evaluate the degree of RFR-FFR concordance at New Cross Hospital, potential reasons for discordance and impacts on patient outcome.Abstract 2-003 Figure 1Calculating pressure ratio across a coronary stenosis. The mean coronary artery pressure distal to a stenosis measured via a PressureWireTM X guidewire (Abbott Vascular Inc., Santa Clara, CA, USA) is divided by the mean pressure in the aorta measured via a guide catheter to calculate the pressure ratioMethods This retrospective analysis included 134 patients with 138 coronary lesions who underwent FFR and RFR assessment. The degree of concordance and discordance between RFR and FFR were determined using an FFR cut-off of ≤0.80 and an RFR cut-off of ≤0.89. Clinical characteristics including presence of hypertension, diabetes mellitus, peripheral vascular disease, chronic kidney disease, atrial fibrillation, as well as previous MI, PCI, and CABG as well as the incidence of cardiovascular events up to 6 months after intracoronary pressure wire testing were collected.Results There was a statistically significant moderate level of concordance between RFR and FFR. The diagnostic accuracy of RFR was 77.5%, and the rate of discordance was 22.5%. Our optimal RFR cut-off of 0.91 suggests an overall underestimation of RFR measurements. The discriminative power of RFR was very good when compared to FFR [AUC: 0.812 (95% CI: 0.731–0.894, p<0.05)] ( figure 2). Whilst peripheral vascular disease (p=0.231) and STEMI (p=0.127) tended to be predictors of RFR-FFR discordance, there was no significant difference detected. The number of patients receiving PCI in concordant and discordant groups was statistically significant (p<0.001)(table 1). Revascularisation was always carried out when FFR was positive, regardless of the RFR result. There were no significant differences in future cardiovascular events, likely because 71% of patients with discordant measurements still received revascularisation treatment.Abstract 2-003 Figure 2ROC curve of RFR vs. FFR in all vesselsAUC, area under curve; FFR, fractional flow reserve; RFR, resting full-cycle ratio; ROC, receiver-operating curve.Abstract 2-003 Table 1The treatment and incidence of cardiovascular events for all data and for separated concordant and discordant groups. CABG, coronary artery bypass grafting; PCI, percutaneous coronary interventionConclusion The RFR-FFR concordance and discordance found in this retrospective analysis supports other studies and promotes the use of a multi-dimensional approach. Treatment decisions based on RFR, even when discordant with FFR, did not necessarily lead to worse patient outcomes, reinforcing the use of RFR as a complementary diagnostic tool. These findings align with emerging evidence that RFR can provide a non-hyperaemic index to effectively complement FFR in clinical decision-making, without compromising patient safety.",
  "authors": [
    {
      "affiliations": [
        "The Royal Wolverhampton NHS Trust"
      ],
      "name": "Harriet Blythe"
    }
  ],
  "title": "2-003 Evaluating how the degree of concordance between intracoronary pressure wire measurements, resting full-cycle ratio and fractional flow reserve, impacts patient outcomes at New Cross hospital",
  "uid": "75a31a84-3caf-5893-b8c5-87608bd8b01e"
}