Prognostic Implications of Comprehensive Whole Vessel Plaque Quantification Using Coronary Computed Tomography Angiography

Background: The prognostic value of whole vessel plaque quantification has not been fully understood. Objectives: We aimed to investigate the clinical relevance of whole vessel plaque quantification on coronary computed tomography angiography. Methods: In a total of 1,013 vessels with fractional flow reserve (FFR) measurement and available coronary computed tomography angiography, high-risk plaque characteristics (HRPC) included minimum lumen area <4 mm², plaque burden ≥70%, low attenuation plaque, positive remodeling, spotty calcification, and napkin-ring sign; and high-risk vessel characteristics (HRVC) included total plaque volume ≥306.5 mm³, fibrofatty and necrotic core volume ≥4.46 mm³, or percent total atheroma volume ≥32.2% in a target vessel, based on corresponding optimal cutoff values. Survival analysis for vessel-oriented composite outcome (VOCO) (a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization) at 5 years was performed using marginal Cox proportional hazard models. Results: Whole vessel plaque quantification had incremental predictability in addition to % diameter stenosis and HRPC (P < 0.001) in predicting FFR ≤0.80. Among 517 deferred vessels based on FFR >0.80, the number of HRVC was significantly associated with the risk of VOCO (HR: 2.54; 95% CI: 1.77-3.64) and enhanced the predictability for VOCO of % diameter stenosis and the number of HRPC (P < 0.001). In a landmark analysis at 2 years, the number of HRVC showed sustained prognostic implications beyond 2 years, but the number of HRPC did not. Conclusions: Whole vessel plaque quantification can provide incremental predictability for low FFR and additive prognostic value in deferred vessels with high FFR over anatomical severity and lesion plaque characteristics.