Int J Cardiovasc Imaging. 2026 Aug 30. doi: 10.1007/s10554-026-03804-8. Online ahead of print.
ABSTRACT
The ramus intermedius (RI) is a variant artery arising from the trifurcation of the left main (LM) coronary artery. While prior work from our group has demonstrated that RI is associated with greater atherosclerotic plaque burden in the LM, whether this anatomical variant is associated with increased overall coronary plaque burden across the entire coronary tree remains unknown. This study aimed to evaluate the relationship between RI presence and total coronary plaque, stenosis, and segment involvement. A large retrospective single-center study was conducted among 11,497 adults who underwent coronary computed tomography angiography (CCTA) between October 2006 and December 2022 in Los Angeles, California. The total plaque score (TPS), total stenosis score (TSS), and segment involvement score (SIS) were quantified for each participant. Differences between individuals with and without an RI were assessed using the Wilcoxon rank-sum test. Negative binomial regression models were constructed with TPS, TSS, and SIS as dependent variables and RI presence as the independent variable, adjusting for traditional cardiovascular risk factors. Among 11,497 subjects (mean age 62.0 ± 12.4 years, 64% male), 1,269 (11%) had an RI. Individuals with RI demonstrated significantly higher TPS (median 6.0 [IQR 2.0-11.0] vs. 3.0 [IQR 0.0-8.0]), TSS (6.0 [IQR 2.0-12.0] vs. 3.0 [IQR 0.0-9.0]), and SIS (5.0 [IQR 2.0-8.0] vs. 3.0 [IQR 0.0-6.0]) compared to those without RI (all p < 0.0001). On multivariable negative binomial regression, RI presence was independently associated with higher TPS (adjusted rate ratio 1.25 [95% CI 1.18-1.33]), TSS (1.27 [1.19-1.35]), and SIS (1.27 [1.21-1.33]) after adjustment for traditional cardiovascular risk factors. The presence of RI is independently associated with greater overall coronary plaque burden, higher stenosis severity, and more widespread coronary segment involvement. These findings suggest that RI may promote diffuse atherosclerosis throughout the coronary vasculature, potentially through hemodynamic perturbations introduced by the additional branching point.
PMID:42669117 | DOI:10.1007/s10554-026-03804-8