Senescent endothelial cells' response to the degradation of bioresorbable scaffold induces intimal dysfunction accelerating in-stent restenosis.

Atherosclerotic cardiovascular disease is a typical age-related disease accompanied by stiffening arteries. We aimed to elucidate the influence of aged arteries on in-stent restenosis (ISR) after the implantation of bioresorbable scaffolds (BRS). Histology and optical coherence tomography showed increased lumen loss and ISR in the aged abdominal aorta of Sprague-Dawley rats, with apparent scaffold degradation and deformation, which induce lower wall shear stress (WSS). This was also the case at the distal end of BRS, where the scaffolds degraded faster, and significant lumen loss was followed by a lower WSS. In addition, early thrombosis, inflammation, and delayed re-endothelialization were presented in the aged arteries. Degradation of BRS causes more senescent cells in the aged vasculature, increasing endothelial cell dysfunction and the risk of ISR. Thus, profoundly understanding the mechanism between BRS and senescent cells may give a meaningful guide for the age-related scaffold design. STATEMENT OF SIGNIFICANCE: The degradation of bioresorbable scaffolds aggravates senescent endothelial cells and a much lower wall shear stress areas in the aged vasculature, lead to intimal dysfunction and increasing in-stent restenosis risk. Early thrombosis and inflammation, as well as delayed re-endothelialization, are presented in the aged vasculature after bioresorbable scaffolds implantation. Age stratification during the clinical evaluation and senolytics in the design of new bioresorbable scaffolds should be considered, especially for old patients.