Association of Tube Voltage With Plaque Composition on Coronary CT Angiography: Results From PARADIGM Registry

Abstract

Objectives: This study sought to investigate the impact of low tube voltage scanning heterogeneity of coronary luminal attenuation on plaque quantification and characterization with coronary computed tomography angiography (CCTA).

Background: The impact of low tube voltage and coronary luminal attenuation on quantitative coronary plaque remains uncertain.

Methods: A total of 1,236 consecutive patients (age: 60 ± 9 years; 41% female) who underwent serial CCTA at an interval of ≥2 years were included from an international registry. Patients with prior revascularization or nonanalyzable coronary CTAs were excluded. Total coronary plaque volume was assessed and subclassified based on specific Hounsfield unit (HU) threshold: necrotic core, fibrofatty plaque, and fibrous plaque and dense calcium. Luminal attenuation was measured in the aorta.

Results: With increasing luminal HU (<350, 350-500, and >500 HU), percent calcified plaque was increased (16%, 27%, and 40% in the median; P < 0.001), and fibrofatty plaque (26%, 13%, and 4%; P < 0.001) and necrotic core (1.6%, 0.3%, and 0.0%; P < 0.001) were decreased. Higher tube voltage scanning (80, 100, and 120 kV) resulted in decreasing luminal attenuation (689 ± 135, 497 ± 89, and 391 ± 73 HU; P < 0.001) and calcified plaque volume (59%, 34%, and 23%; P < 0.001) and increased fibrofatty plaque (3%, 9%, and 18%; P < 0.001) and necrotic core (0.2%, 0.1%, and 0.6%; P < 0.001). Mediation analysis showed that the impact of 100 kV on plaque composition, compared with 120 kV, was primarily caused by an indirect effect through blood pool attenuation. Tube voltage scanning of 80 kV maintained a direct effect on fibrofatty plaque and necrotic core in addition to an indirect effect through the luminal attenuation.

Conclusions: Low tube voltage usage affected plaque morphology, mainly through an increase in luminal HU with a resultant increase in calcified plaque and a reduction in fibrofatty and necrotic core. These findings should be considered as CCTA-based plaque measures are being used to guide medical management and, in particular, when being used as a measure of treatment response. (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging [PARADIGM]; NCT02803411).

Keywords: coronary computed tomography angiography; coronary plaque; luminal attenuation; mediation analysis; tube voltage.

Conflict of interest statement

Funding Support and Author Disclosures This work was supported by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT (MSIT) (grant number 2012027176). The study was also funded in part by a grant from the Dalio Foundation (New York, New York). Dr Leipsic receives institutional grants to provide core lab services to Edwards Life Sciences, Abbott, Boston Scientific, and Medtronic and is a consultant to and has stock options in Circle CVI and HeartFlow. Dr Andreini is on the Speakers Bureau for GE Healthcare and receives grant support from GE Healthcare and Bracco. Dr Budoff has received grant support from the National Institutes of Health and GE Healthcare. Dr Chun has received funding from a National Research Foundation grant funded by the South Korea government (MEST) (NRF- 2015R1D1A1A01059717). Dr Pontone has received institutional research grants from GE Healthcare, HeartFlow, Medtronic, Bracco, and Bayer. Dr Virmani has received institutional research support from 480 Biomedical, Abbott Vascular, ART, BioSensors International, Biotronik, Boston Scientific, CeloNova, Claret Medical, Cook Medical, Cordis, Edwards Lifesciences, Medtronic, MicroVention, OrbusNeich, ReCord, SINO Medical Technology, Spectranetics, Surmodics, Terumo Corporation, W.L. Gore, and Xeltis; has received honoraria from 480 Biomedical, Abbott Vascular, Boston Scientific, Cook Medical, Lutonix, Medtronic, Terumo Corporation, and W.L. Gore; and is a consultant for 480 Biomedical, Abbott Vascular, Medtronic, and W.L. Gore. Dr Samady has received grant support from Phillips/Volcano and St. Jude Abbott/Medtronic/Gilead. Dr Berman has received software royalties from Cedars-Sinai. Dr Bax has received unrestricted research grants from Biotronik, Medtronic, Boston Scientific, and Edwards Lifesciences. Dr Chang has received funding from the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT, and Future Planning (grant 2012027176). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.