P6185Impact of coronary atherosclerotic plaque metrics on the correlation between on-site CT-FFR and invasive FFR

Abstract

Abstract Background Developed in the last years, coronary computed tomography-derived fractional flow reserve (CT-FFR) has shown good correlation with invasive fractional flow reserve (FFR). However, little is known about the interaction of coronary atherosclerotic plaque characteristics in the correlation between CT-FFR and FFR. Purpose This study sought to determine the effect of main coronary atherosclerotic plaque metrics (APM) on the correlation between on-site CT-FFR and invasive FFR. Methods Patients referred for invasive coronary angiography (ICA) who accepted to undergo a CT-FFR study were prospectively included. We excluded patients with atrial fibrillation, chronic total occlusions, severe ventricular hypertrophy or previous coronary revascularization, and those with any contraindication for CT. On-site CT-FFR and APM were calculated for each coronary vessel. Continuous variables of APM were dichotomized as above and below the median and their interaction on the correlation between on-site CT-FFR and invasive FFR was assessed by multiple linear regression model. Results 33 patients (90 vessels) were included. Mean age was 65±10 years, 88% were males, 60% had hypertension, 77% dyslipidaemia and 40% diabetes. The mean delay time between CTA and ICA of 21 days. The average analysis time of CT-FFR was 16±4 minutes. Overall, correlation between FFR and CT-FFR showed a Pearson's r coefficient of 0.77±0.06 and a standardized beta coefficient of 0.8 (p<0.001). The beta coefficients between CT-FFR and FFR did not change significantly after the interaction with different APM (p>0.05 for all) (see Table). Standardized Beta coefficients for on-site CT-FFR with invasive FFR as a gold standard Below the median Above the median p value for interaction Total atheroma volume (TAV) (mm3) 0.66 0.93 0.071 Percent atheroma volume (PAV) (%) 1.00 0.69 0.063 Calcified atheroma plaque volume (%) 0.89 0.68 0.175 Remodeling index 0.94 0.71 0.129 Lesion length (LL) (mm) 0.67 0.89 0.158 Minimal lumen area (mm2) 0.73 0.71 0.955 Conclusions There is a good correlation between on-site CT-FFR and invasive FFR, which is not affected by main atherosclerotic plaque characteristics.