Retrospective Analysis of In-Stent Restenosis in Diabetic Patients

Background In-stent restenosis (ISR) remains a major clinical challenge in diabetic patients undergoing percutaneous coronary intervention (PCI), despite the widespread use of drug-eluting stents (DES). Objective This study aims to determine the incidence of ISR and identify associated clinical and procedural risk factors in diabetic patients following PCI with DES. Materials and methods This retrospective study was conducted at Akhtar Saeed Trust Hospital, Lahore, Pakistan, from April 2023 to April 2025. A total of 265 diabetic patients who underwent PCI with DES implantation and later presented for follow-up angiographic evaluation were enrolled in the study. Participants were selected through non-probability consecutive sampling. Data were collected using a structured proforma, which included demographic information (age, sex), clinical history (duration of diabetes, smoking status, hypertension, dyslipidemia), laboratory parameters (HbA1c, fasting glucose, lipid profile), and procedural details (number, type, and length of stents used; lesion characteristics; and target vessel). Results ISR was observed in 76 out of 265 patients (28.7%). Patients with ISR had significantly higher HbA1c levels (8.6 ± 1.2% vs. 7.3 ± 1.1%, p < 0.001), longer duration of diabetes (11.1 ± 4.3 vs. 8.4 ± 4.2 years, p < 0.001), and more frequent use of long stents and smaller stent diameters. Multivariate regression identified poor glycemic control (OR 2.83, p < 0.001), diabetes duration > 10 years (OR 2.45, p = 0.005), and stent length >28 mm (OR 1.96, p = 0.015) as independent predictors of ISR. ISR patients were also more symptomatic at follow-up. Conclusions ISR remains a frequent and serious complication in diabetic patients after PCI. Poor glycemic control, longer disease duration, and certain stent characteristics significantly contribute to its development.