BACKGROUND No scoring models for IS-CTO have been established because of its in-stent characteristics. The purpose of this study was to develop a scoring model to predict the technical success of recanalizing in-stent chronic total occlusion (IS-CTO) by percutaneous coronary intervention (PCI). METHODS We retrospectively collected data from 474 patients who underwent an IS-CTO PCI from January 2015 to December 2018, consecutively. We selected clinical and angiographic factors and utilized a derivation and validation cohort (4:1 sampling ratio) analysis. Factors with strong correlations with technical failure, according

Vascular calcification (VC), a significant risk factor of many cardio‐cerebral vascular diseases, is a perplexing issue with no effective treatment in clinical work up to now. Endoplasmic reticulum stress (ERS) mediated apoptosis has been proved to be a significant mechanism for initiating VC process. Activating transcription factor 4 (ATF4), a key transcription factor of ERS, is most closely associated with VC. Fibroblast growth factor 21 (FGF21), an atypical member of the FGFs family, has a protective biological function in various metabolic diseases by ERS pathways. However, the possible effects of FGF21 on VC by regulating ERS, especially through the ATF4 pathway, is still unclear. Our research provides the first evidence that exogenous FGF21 treatment can alleviate the vitamin D3 plus nicotine‐induced VC at least in part via suppressing ATF4 mediated apoptosis and osteogenic transformation in rats.