Comparison of two angiography-based FFR techniques in NSTEMI Patients: A Multicenter Study

Abstract

Abstract Background Recently, non-invasive methods ("wire free") to functionally assess the hemodynamic severity of a coronary artery have emerged. FFRangio and QFR are angiography-based technologies that have been validated in patients with chronic and acute coronary syndrome compared to invasive FFR measurement. To date, no direct comparison between these two methods has been reported and they have never been prospectively evaluated in patients presenting exclusively with Non-ST Segment Elevation Myocardial Infarction (NSTEMI). Methods Patients with NSTEMI were prospectively included in this multicenter, single-arm, double-blinded study comparing FFR calculated by FFRangio and QFR - both calculated offline - to invasively-measured FFR (FFRinvasive). FFRinvasive was measured in all angiographically intermediate lesions (30%-70% stenosis) and was then compared to the average value measured by two blinded operators for each angio-based FFR modalities; FFRangio and QFR. The primary endpoints were the sensitivity and specificity of FFRangio and QFR relative to the reference standard FFRinvasive using a cutoff value of ≤0.80. Results Among 129 NSTEMI patients who were screened, 49 patients with 63 vessels in total underwent FFRinvasive measurements, had optimal angiographical views for FFRangio and QFR measurement, and were finally included in the study. The mean value of FFRinvasive was 0.83±0.3 with 22 (36%) being ≤0.80. The mean FFRangio was 0.83±0.1 with 20 (32%) being ≤0.80. FFRangio exhibited a sensitivity of 91%, a specificity of 100% and a diagnostic accuracy of 96.8%. The mean QFR was 0.82±0.3 with 20 (32%) being ≤0.80 and it showed sensitivity of 86.4%, specificity of 98.4% and diagnostic accuracy of 93.7%.The pearson correlation coefficient for FFRangio and QFR were r=0.91 and r=0.76, respectively. Conclusion To our knowledge, this multicenter study represents the first head-to-head comparison between these two non-invasive angiography-derived physiology assessment modalities. Both, FFRangio and QFR, that were performed by two operators, demonstrated great diagnostic performance which is slightly better compared to previous validation studies. Although, based on our study, FFRangioseems to have better sensitivity, further larger validation studies are required.Bland–Altman plotCorrelation for FFR and Angio-Based FFR