Comparison of angiogram-based physiological assessment system sizing tool and intravascular ultrasound imaging measurements.

Abstract

Background: The diagnostic performance of an angiogram-based physiological assessment system (FFRangio™, CathWorks) has been already demonstrated. Besides performing a functional assessment, the FFRangio system provides a 3-dimensional quantitative coronary angiogram-based sizing tool (FFRangioST) to measure lumen diameter and vessel length. We aim to compare the measurements obtained using FFRangioST against measurements obtained with intravascular ultrasound (IVUS) in patients undergoing percutaneous coronary intervention (PCI).

Methods: We analyzed data from consecutive patients who underwent IVUS-guided PCI after FFRangio physiological assessment and FFRangioST assessment of lesion diameters and length from the Japan FFRangio clinical outcome registry (ClinicalTrials.gov. NCT05648396). For each lesion undergoing PCI, the correlation and mean difference for lesion length (LL), proximal reference diameter (RD) and distal RD as measured by FFRangioST/IVUS were assessed using pairwise comparisons, Pearson's correlation and Bland-Altman plots.

Results: Our cohort included 121 lesions from 115 patients. The FFRangio value in this cohort was 0.60 ± 0.1 (mean ± standard deviation). Mean LL (mm) was 31.1 ± 13.9 and 30.3 ± 14.3 by FFRangioST and IVUS, respectively. Correlation between the LL measurements was r = 0.986 (p < 0.001). Proximal RD (mm) was 2.6 ± 0.5 and 3.2 ± 0.6 by FFRangioST and IVUS, respectively, with correlation of r = 0.756 (p < 0.001). Distal RD (mm) was 2.2 ± 0.5 and 2.7 ± 0.5 by FFRangioST and IVUS, respectively, with correlation of r = 0.832 (p < 0.001). After inflating the original FFRangioST diameter value by 25 %, the average difference between the IVUS and FFRangioST measurements was 0.02 mm and -0.02 mm, for proximal and distal RD, respectively.

Conclusion: FFRangioST measurement has an excellent correlation with lesion length and high degree of correlation with a predictable coefficient (25 % inflation) with proximal and distal reference diameters when compared with IVUS measurement in PCI.