Introduction: The coronary CT angiography (CCTA)-based differences in composition, morphology and vulnerability of coronary plaques (CPs), according to their locations within the coronary tree, have not been investigated so far.
Objective: We sought perform a comparative analysis between atherosclerotic plaques located at different levels within the coronary tree, in order to identify the differences in plaque composition, morphology, and vulnerability between the three major coronary bran-ches.
Methods: We conducted a cross-sectional, observatio-nal study on 75 patients with stable coronary artery di-sease who underwent CCTA for assessment of coronary lesions that exhibited at least one vulnerability marker in the coronary tree (low attenuation plaque – LAP; napkin ring sign – NRS; spotty calcifications – SC; po-sitive remodeling – PR). Coronary plaque analysis (de-gree of stenosis, plaque composition and morphology, vulnerability markers) was performed with the use of the Syngo.via Frontier (Siemens) software. In total, 90 coronary VPs located at the level of the left anterior descending (LAD; n=30), circumflex (CXA; n=30) and right coronary artery respectively (RCA; n=30) were identified and analyzed.
Results: CPs in the RCA presented a significantly hi-gher length (LAD- 18.6± 5.4 vs. CXA- 15.4 ±3.7 vs. RCA- 20.4±5.9 mm, p=0.001), a higher degree of ste-nosis (LAD- 57.7 ± 8.6 vs. CXA- 54.5 ± 11.2 vs. RCA-59.6 ± 10.4 mm, p=0.022), and were more voluminous (LAD- 187.9 ± 86.0 vs. CXA- 146.9 ± 102.4 vs. RCA-248.1 ± 11.4 mm3, p=0.0007) compared to those loca-ted in the LAD and CXA. Plaque composition was also significantly different: calcified volume (LAD – 44.0 ± 63.9 vs. CXA- 12.4 ± 19.6 vs. RCA- 33.6 ± 34.3 mm3, p=0.002), non-calcified volume (LAD- 143.8 ± 76.02 vs. CXA- 134.5 ± 102.2 vs. RCA- 214.4 ± 99.6 mm3, p=0.002), lipid rich volume (LAD- 14.9 ± 22.6 vs. CXA-6.4 ± 13.4 vs. RCA- 16.0 ±15.7 mm3, p=0.0005), fibrotic volume (LAD- 128.9 ± 66.1 vs. CXA- 128.1 ± 91.5 vs. RCA- 198.3 ± 92.3 mm3, p=0.003). The highest number of VM per plaque was present in the LAD (LAD- 2.2 ± 0.8 vs. CXA- 1.6 ± 0.7 vs. RCA- 1.8 ± 0.6, p=0.01).
Conclusions: Coronary plaques located in the RCA are more voluminous and exhibit a higher volume of lipid rich and non-calcified atheroma. However, compared to the RCA and CXA, the left anterior descending ar-tery presented CPs with a more expressed degree of vulnerability, a higher number of vulnerability markers per plaque, and a higher incidence of LAP.