In vivo Predictors of Focal Type In-stent Restenosis: A Clinical, Angiographical and Optical Coherence Tomography Study

Introduction：Few studies have evaluated different patterns of in-stent restenosis by optical coherence tomography (OCT). This study aims to identify in vivo predictors for focal restenosis in patients with in-stent restenosis (ISR). Methods: The study recruited patients with ISR who underwent OCT examination in the Cardiology Department of the Affiliated Hospital of Zunyi Medical University from October 2018 to December 2022. Based on the angiographic classification of ISR lesions, the patients were divided into two groups: the focal group (n=58) and the non-focal group (n=158). Results： The white blood cell count was higher in the non-focal group than those in focal type (7.8±3.0 vs. 6.6±2.1, P = 0.007). The prevalence of lipid rich plaque was higher in patients with focal ISR (65.5% vs. 42.4%, P = 0.003). The occurrence of red thrombus (27.8% vs. 12.1%, P = 0.016) and white thrombus (41.1% vs. 24.1%, P = 0.021) was higher in the non-focal group. Multivariate analysis showed that low density lipoprotein cholesterol C (odds ratio [OR]:3.341, 95% confidence interval [CI]: 1.714-9.784, P = 0.046) was independently associated with focal restenosis. While white blood cell count (OR: 0.814, 95% CI: 0.657-0.913, P = 0.047) and stent malapposition (OR: 0.228, 95% CI: 0.057-0.896, P = 0.037) were independently associated with non-focal restenosis. Conclusion：There were significant differences in clinical baselines and OCT identified morphological characteristics in patients between focal and non-focal group. Low density lipoprotein cholesterol C was independent associated with focal restenosis. White blood cell count and stent malapposition were correlated with non-focal restenosis.