AIMS:

The diagnostic performance of an angiogram-based physiological assessment system (FFRangio; Cathworks, Israel & CA, United States) has been already demonstrated. The system provides a 3D quantitative coronary angiogram based sizing tool (FFRangioST) to measure vessel anatomy and geometry.  We aim to compare the measurements obtained using this FFRangioST against measurements obtained with intravascular ultrasound (IVUS) in patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS:

We analyzed 121 vessels (115 consecutive patients) which underwent IVUS-guided PCI after FFRangio physiological assessment from the Japan FFRangio clinical outcome registry (ClinicalTrials.gov. NCT05648396), which is an investigator initiated multicenter registry of patients undergoing FFRangio guided treatment for coronary artery disease at 7 centers (Japan- 6, Israel- 1). An investigator determined the segment of interest for stenting on 2D angiograms and utilized the FFRangioST to determine minimum lumen diameter (MLD), proximal and distal reference diameters (RD) and lesion length (LL) in FFRangio system analyzed by radiotechnologists or interventional cardiologists at each hospitals. The IVUS measurement was independently analyzed to obtain MLD, minimum lumen area, lumen RD, and LL. Statistical analyses including descriptive statistics, pairwise comparisons, Pearson’s correlation, Bland-Altman plots and linear regression and covariate analyses were performed. The FFRangio value in this cohort was 0.60±0.1 (mean±standard deviation). Mean LL was 31.1±13.9 mm and 31.2±15.4 mm by FFRangioST and IVUS, respectively. Correlation between the measurements was excellent (Pearson’s r=0.986, p<0.001). Proximal RD was 2.6±0.5mm and 3.2±0.6mm by FFRangioST and IVUS, respectively, with good correlation (Pearson’s r=0.756, p<0.001). Distal RD was 2.2±0.5mm and 2.7±0.5 by FFRangioST and IVUS, respectively with strong correlation (Pearson’s r=0.832, p<0.001). After multiplying the value of FFRangioST diameters by 1.25 (25% inflation), the linear regression for proximal and distal RD closely matched the unity line.

CONCLUSION:

FFRangioST measurement has a high degree of correlation in LL and RD compared with IVUS in PCI. These results highlight the potential for FFRangio to provide both physiologic assessment regarding lesion severity, as well as anatomic assessment for PCI planning. This function would be useful in PCI for cases where intravascular imaging is not performed.