Pathophysiology of Coronary Restenosis.

In-stent restenosis (ISR) remains a major clinical issue despite the widespread use of new-generation drug-eluting stents (DESs). Although DESs are effective in reducing neointimal hyperplasia, delayed endothelial healing and neoatherosclerosis are key complications of ISR that remain unresolved. Recent advances in noninvasive and intravascular imaging techniques have improved lesion assessment, while treatment options such as additional DES implantation and drug-coated balloons have become more widely available. Understanding ISR pathophysiology, together with the appropriate use of imaging modalities, is essential for selecting optimal therapies and guiding future development of ISR treatments and next-generation DESs.