Impact of optical coherence tomography on outcomes following percutaneous coronary intervention for in-stent restenosis in patients with diabetes mellitus and prediabetes: A single-center, retrospective study

Objectives: In-stent restenosis (ISR) remains a major complication of percutaneous coronary intervention (PCI), with diabetes mellitus (DM) and prediabetes amplifying risk through endothelial dysfunction and chronic inflammation. Although intravascular imaging techniques, such as optical coherence tomography (OCT), improve ISR management, evidence of their prognostic benefits in patients with DM or prediabetes remains limited. This study aimed to compare clinical outcomes between OCT- and angiography-guided PCI in patients with DM or prediabetes experiencing ISR. Methods: This single-center, retrospective study included 314 patients with DM or prediabetes who underwent PCI for ISR. Patients were stratified into two groups: OCT-guided ( n = 215) and angiography-guided ( n = 99) groups. Baseline characteristics, procedural parameters, and clinical outcomes were analyzed. The primary endpoint was the occurrence of major adverse cardiovascular events (MACEs), defined as a composite of cardiovascular death, myocardial infarction, and revascularization. Results: OCT-guided PCI significantly reduced the 3-year risk of MACEs (hazard ratio [HR]: 0.45, 95% confidence interval [CI]: 0.22-0.92; p = 0.047) and yielded superior angiographic results, including larger minimal lumen diameter (2.27 vs. 1.99 mm, P < 0.01), lower residual stenosis (15.98% vs. 27.12%, P < 0.01), and enhanced lumen gain (1.85 mm [interquartile range: 1.45-2.12] vs. 1.60 mm [interquartile range: 1.23-1.98]; P = 0.02). Cox regression analysis identified OCT guidance (HR: 0.47, 95% CI: 0.33-0.68), the use of drug-eluting stent (HR: 0.53, 95% CI: 0.31-0.92), and larger pre-PCI reference lumen diameter (HR: 0.66, 95% CI: 0.44-0.99) as independent protective factors against 3-year MACEs. Conversely, prior heart failure (HR: 3.6; 95% CI: 2.14-6.07) was an independent risk factor. Subgroup analyses showed significantly enhanced MACE reduction in non-smokers, patients without prior heart failure, and drug-eluting stent users (interaction P < 0.05). Conclusion: OCT-guided PCI significantly improves 3-year outcomes in patients with DM or prediabetes experiencing ISR, particularly among non-smokers, patients without prior heart failure, and recipients of drug-eluting stents.