Incremental value of physiological indices to predict high-risk plaque detected by NIRS-IVUS

Abstract

Abstract Background The vulnerable plaque are called high-risk plaques (HRPs), and coronary computed tomography angiography (CCTA) studies have revealed the following characteristics: (1) lesion plaque density on CT≦30HU (2) positive remodeling, (3) The presence of spotty calcification, (4) ΔFractional Flow Reserve derived from CCTA (FFRCT) or Δ Quantitative Flow Reserve (QFR)≧0.06 has been cited as a feature of these lesions. Therefore, identification of HRPs in non-culprit lesion is important to reduce future cardiovascular events. Purpose The purpose of the study was to determine whether HRP is predictable by incremental values of physiological indices in non-culprit lesions of ACS subjects. Methods A total of 137 non-culprit coronary lesions in 31 ACS subjects were retrospectively evaluated by CCTA, FFRCT, QFR and NIRS-IVUS imaging. Each coronary artery was divided into 30mm long segments beginning at the ostium to evaluate lesion vulnerability. By NIRS imaging, plaque with 4-mm maximum lipid-core burden index (maxLCBI4mm) ≥400 was defined as HRP. The relationship between HRP detected by NIRS and CCTA-derived plaque features, delta (Δ) FFRCT, and ΔQFR was evaluated. Results CT density, positive remodeling, diameter stenosis, ΔFFRCT, and ΔQFR were significantly associated with HRP, respectively (P<0.05). On multivariable analysis, CT density (OR; 0.95, 95%CI 0.91-0.99, P=0.0001), diameter stenosis (OR; 1.05, 95%CI 1.00-1.10, P=0.03) and ΔQFR (OR; 2119483 , 95%CI 1.75-2561856632475.6, P=0.03) independently predicted HRP, but not ΔFFRCT. ROC analysis for predicting HRP showed greater accuracy with incremental ΔQFR values in the model of CT density and diameter stenosis (AUC 0.93, P<0.0001). Conclusion HRP detected by NIRS may be predicted with greater accuracy by integrating QFR values with the assessment of CCTA-derived plaque features.figure1figure2