Coronary computed tomography angiography study on the relationship between the Ramus Intermedius and Atherosclerosis in the bifurcation of the left main coronary artery

Abstract

Objective This study aimed to explore the relationship between the ramus intermedius (RI) and atherosclerosis in the bifurcation of the left coronary artery (LCA). Methods Screening patients who underwent CCTA from January to September 2021, 100 patients with RI (RI group) and 100 patients without RI (no-RI group) were randomly enrolled, Evaluation of RI distribution characteristics and left main coronary artery(LM),Left anterior descending branch(LAD),left circumflex branch(LCX) proximal segment plaque distribution, measurement of LAD-LCX bifurcation angle(∠LAD-LCX),Comparison of the three distribution characteristics with the incidence of plaques in the left main trunk bifurcation area (LM, LAD, LCX) between groups and within the RI group. Results The difference in the incidence of plaques in the proximal LCX and the LM between the RI group and the no-RI group were not statistically significant (P > 0.05). The incidence of plaques in the proximal LAD in the RI group was significantly higher than that in the non-RI group (77% versus 53%, P < 0.05). However, there was no statistically significant difference between the two groups after PSM. A univariate logistic regression analysis revealed that an RI was a risk factor for plaque formation in the proximal LAD (P < 0.001), and a multivariate logistic regression analysis revealed that an RI was not an independent risk factor for plaque formation in the proximal LAD (P > 0.05). When compared within the RI group, the difference in the incidence of plaques in the proximal segment of LAD, the proximal segment of LCX, and the LM among the different distribution groups of RI was not statistically significant, respectively (P > 0.05). Conclusion RI is not an independent risk factor for atherosclerosis in the left coronary artery bifurcation zone, but it may indirectly increase the risk of atherosclerosis in the proximal segment of the LAD.

The Ramus Intermedius: A Bridge to Survival in the Setting of Triple-Vessel Total Occlusion

“…However, if RI is precisely positioned between these arteries, its effect on their proximal diameter is minimal [19]. Additionally, some data indicate that the existence of RI is associated with an increased risk of branch point atherosclerosis [10,11,12,20]. These considerations underscore the complex interplay between RI anatomy and its potential implications for coronary artery health.…”

“…Some reports suggest that the presence of RI increases the risk of atherosclerotic plaque formation and obstructive lesions in the left main and proximal LAD [10,12]. Zhang et al demonstrated that the presence of RI is not an independent risk factor for atherosclerotic plaque formation in the LMCA bifurcation zone, but it may indirectly increase the risk of atherosclerosis in the proximal segment of the LAD [11]. Another review highlighted the association between RI and larger anterior infarctions as well as more proximal LAD lesions [20].…”

“…Consequently, the RI, as an additional flow divider, may potentially contribute to the generation of additional pathologic shear stress, atherosclerotic plaque formation, and damage to the coronary endothelium [9]. Consistent with this hypothesis, some data have emerged, indicating that the presence of RI is associated with an elevated risk of atherosclerotic plaque development within the LMCA and the proximal segment of the LAD [10][11][12]. However, conflicting reports suggest a protective role of the RI, especially in cases of multivessel CAD [13].…”

Left Main Coronary Artery Disease: A Contemporary Review of Diagnosis and Management

“…[ 29 ] showed that CCTA could effectively rule out in-stent restenosis in patients with a prior PCI. CCTA may also be beneficial to stratify cardiovascular risk through other measurements and anatomic variants that could predispose to the formation of atherosclerotic plaques [ 30 , 31 ].…”