Impact of endothelial shear stress on absorption process of resorbable magnesium scaffold: A BIOSOLVE-II substudy.

Abstract Background/Purpose Local hemodynamic forces such as endothelial shear stress (ESS) may have an influence on appropriate neointimal healing, vessel remodeling, and struts absorption process following second-generation drug-eluting resorbable magnesium scaffold (RMS, Magmaris, Biotronik AG, Buelach, Switzerland) placement. The aim of this study was to investigate the impact of ESS assessed by optical coherence tomography (OCT)-based computational fluid dynamic (CFD) simulations on absorption process and coronary lumen dimension after Magmaris implantation. Methods and Results A total of 22 patients who were enrolled in the BIOSOLVE-II trial and underwent serial OCT assessment immediately after Magmaris implantation and at 6- and 12-month follow-up were included. We evaluated qualitative OCT findings frame by frame, and CFD simulations were performed to calculate the ESS at 3-dimensional (3D) reconstructed arteries. For quantitative calculation, the average ESS within each 1-mm section was classified into three groups: low ( 2.5 Pa). A significant difference of percentage remnants of scaffold was observed among the 3 groups at 12-month follow-up (P=0.001) but not at 6-month follow-up. Low-ESS segment at baseline resulted in a greater lumen change of -1.857±1.902 mm2 at 1 year compared to -1.277±1.562 mm2 in the intermediate-ESS segment (P=0.017) and -0.709±1.213 mm2 in the high-ESS segment (P=0.001). Conclusion After Magmaris implantation, the presence of higher ESS might be associated with slower strut absorption process but less luminal loss. Summary for table of contents The authors analyzed 22 patients from the BIOSOLVE-II trial who underwent optical coherence tomography assessment immediately after receiving a Magmaris second-generation drug-eluting resorbable magnesium scaffold. The analysis found that after Magmaris implantation, the presence of higher endothelial shear stress (ESS) might be associated with slower strut absorption process but less luminal loss. This study is the first demonstrating the impact of ESS assessed by OCT on absorption process and coronary lumen dimension after Magmaris implantation.