Abstract 10860: Association Between Fractional Flow Reserve and Coronary Plaque Characteristics Assessed by Optical Coherence Tomography

Abstract

Introduction: The assessment of fractional flow reserve (FFR) in coronary lesions determines the strategy of percutaneous coronary intervention. However, the association between FFR and characteristics of underlying coronary plaque has not been sufficiently investigated. Methods: A total of 110 coronary lesions in 106 patients were evaluated using both FFR and optical coherence tomography (OCT). Coronary plaque was classified into fibrous, fibrocalcific, or fibroatheroma according to OCT evaluation at the site of minimal lumen area. Plaque microstructures such as cap thickness, macrophage accumulation, intimal vasculature, or cholesterol crystal were also evaluated. Results: Compared to lesions with FFR >0.8, those with FFR ≤0.8 showed a higher frequency of fibroatheroma, macrophage accumulation, and cholesterol crystal. However, multiple linear regression analysis revealed that any morphological characteristics of plaques assessed by OCT were not independently associated with FFR. Minimal lumen area (coefficient, 0.036; 95% confidence interval [CI], 0.022-0.049; p<0.001) and area stenosis (coefficient, - 0.003; 95% CI, -0.005--0.001; p<0.001) assessed by OCT significantly correlated with FFR. Thin-cap fibroatheroma was identified in 12 (10.9%) of all 110 lesions. There were no significant differences of minimal lumen area, area stenosis, or FFR between lesions with and without thin-cap fibroatheroma. Conclusions: Morphological characteristics of coronary plaque are not directly related to FFR. Conversely, the extent of functional or anatomical stenosis cannot identify the lesion with thin-cap fibroatheroma.