Transfer of Low-Density Lipoproteins in Coronary Artery Bifurcation Lesions with Stenosed Side Branch: Numerical Study

Evidence from clinical data suggests that the stenotic side branch (SB) is one of the key predictors for SB occlusion-based adverse events. In this study, we hypothesized that coronary bifurcations with stenotic SB might lead to severe concentration polarization of atherogenic lipids, such as the low-density lipoproteins (LDL), motivating the adverse events in the clinic. To confirm this hypothesis, this work numerically investigated the transport of LDL in different bifurcation lesions based on the Medina classification with various location and stenosis severities. The results showed that the coronary bifurcations with stenotic SB might be suffering more serious concentration polarization of LDL on the luminal surface of the SB due to higher level of LDL concentrations. Moreover, compared to the other bifurcation lesion types, the type (1,0,1) had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis. In addition, this study also showed that the luminal surface LDL concentration increased with elevated stenosis severity. The type (1,0,1) with the severe stenosis (75% diameter reduction) had the highest concentration at the SB. In conclusion, these results suggested that both location of lesions and stenosis severities had great influence on the distribution of LDL on the luminal surface of the SB. Therefore, the estimation of disease severity and the interventional therapy should be carried out not only according to the stenosis severities in clinic. Moreover, compared to the other bifurcation lesion types, the type (1,0,1), rather than the type (1,1,1) as usually considered, had the highest luminal surface LDL concentration along the SB and the highest degree of risk to enhance the process of atherosclerosis.