Advanced CCTA imaging, angiography-based Radial Wall strain and μFR versus IVUS-NIRS to enhance identification of lipid-rich vulnerable plaques: A multimodality imaging approach

Background and aims: Identifying vulnerable coronary plaques (VP) is essential for stratifying cardiovascular risk in stable coronary artery disease (CAD). This is the first study to assess diagnostic performance in detecting VP of CCTA advanced plaque analysis, including maximal plaque burden (PBmax) and necrotic core area, angiography-derived radial wall strain (RWSmax) and Murray's quantitative flow ratio (μFR) by using Intravascular Ultrasound with Near-Infrared Spectroscopy (IVUS-NIRS) as gold standard. Methods: We analyzed fifty lesions from forty-three patients who underwent coronary angiography with IVUS-NIRS following CCTA. VP were defined using IVUS-NIRS criteria as maximal Lipid Core Burden Index ≥325. Regression analyses evaluated associations between the imaging parameters and VP. Receiver-operating-characteristic (ROC) curves and the corresponding areas under the curve (AUCs) were calculated to quantify the diagnostic performance of each model. Results: VP was found in 19 out 50 lesions (38%) and in 16 out of 43 patients (37%). About CCTA, PBmax and necrotic core area showed the highest accuracy in identification of VP (AUC = 0.839 and AUC = 0.876, respectively). Regarding invasive evaluation, angiography-derived RWSmax demonstrated significant discriminative ability for detecting VP, whereas μFR did not (AUC = 0.921 and AUC = 0.637, respectively). Two multivariate models were tested: the first, combining PBmax and RWSmax, achieved an AUC of 0.959; the second model, based only on CCTA-derived parameters (PBmax and necrotic core area), yielded an AUC of 0.939. Although the difference between the two AUCs was not statistically significant, the combined model substantially improved the positive predictive value compared to the CCTA-only model (93.8% vs. 76.2%). Conclusions: Integrating CCTA-derived PBmax with angiography-derived RWSmax provides high discrimination of VP and may guide selective referral to IVUS-NIRS for definitive characterization.