Comparison between fractional flow reserve and visual assessment for moderate coronary artery stenosis

Background: Fractional flow reserve (FFR) is an interventional diagnostic method, based on intracoronary pressure measurement, used for the assessment of the severity of coronary artery stenoses. Aim: Our study aimed to compare visual measurements made by multiple observers with FFR measurement in the assessment of angiographically moderate coronary artery stenosis. Methods: The angiographic images of moderate coronary artery lesions of 359 patients enrolled in the study were interpreted independently by three interventional cardiologists assigned as observers (O1, O2, O3). Results: In FFR, 37.9% were haemodynamically significant, while 62.1% were insignificant. 40.3% of the lesions were considered severe by O1, 39.9% by O2, and 44.4% by O3. When we compare the FFR results to the observers’ decisions about lesion severity, the serious lesion percentages of all three observers were different both from each other and from the FFR result, at a statistically significant level (respectively, p < 0.001, p < 0.001). The kappa analysis performed to check the agreement between the observers’ decisions and FFR revealed significant difference between FFR results and the decisions made by all observers (p < 0.001). The kappa agreement analysis performed by matching observers’ decisions in pairs revealed a good agreement between O1 and O2 and a moderate agreement between O2 and O3 as well as O1 and O3, although there was still a significant disagreement between all pairs of observers (p < 0.001). Conclusions: Visual assessment, even when performed by experienced interventional cardiologists, does not yield similar results with FFR procedure in the process of determination of the functional importance of moderately severe coronary artery stenoses.