The Clinical Spectrum and Management of Patients with Coronary in-Stent Restenosis

Background and Aim: In-stent restenosis (ISR) remains a clinically important limitation of percutaneous coronary intervention (PCI), contributing to recurrent ischemia, repeat revascularization, and adverse outcomes.Despite the widespread use of drug-eluting stents, ISR persists.This study aims to evaluate the prevalence, clinical spectrum, and predictors of ISR in a contemporary tertiary-care setting. Materials and Methods:A retrospective-prospective observational study was conducted between November 2018 and November 2019.Among 350 angiographic records reviewed, 100 patients with prior PCI were included in the study and underwent clinically driven coronary angiography.ISR was defined as ≥50% luminal narrowing within or adjacent to the stented segment and was classified as focal or non-focal according to the Mehran system.Demographic, clinical, and procedural data were analyzed.Results: ISR was identified in 50 patients (50%); 38 patients (38%) required target lesion revascularization.Factors associated with ISR included male sex (90% vs. 46%, P < 0.001); diabetes mellitus (72% vs. 38%, P < 0.001); longer stent length (25.4±9.2 vs. 20.3±4.9 mm, P < 0.001); smaller stent diameter (3.02±0.40 vs. 3.41±0.29mm, P < 0.001); and left anterior descending artery (LAD) involvement (52% vs. 10%, P = 0.002).Diffuse ISR was present in 46% of patients and was significantly associated with LAD (78.3%) and right coronary artery (56.5%) lesions, smaller vessel size, longer stents, and adverse outcomes, including one death.Conclusions: ISR affected half of the patients undergoing clinically indicated repeat angiography and was associated primarily with procedural and angiographic characteristics, including smaller vessel caliber, longer stent length, and LAD involvement.