Abstract
BACKGROUND: Vertebral artery stenosis, especially at the ostium, is a significant cause of posterior circulation ischemic events. Although drug-eluting stents (DESs) have demonstrated superior efficacy in reducing restenosis compared to bare-metal stents (BMSs), the specific incidence and predictors of in-stent restenosis (ISR) following DES implantation in patients with ostial vertebral artery stenosis (OVAS) remain inadequately investigated. METHOD: This single-center retrospective study evaluated 446 patients who underwent DES implantation for OVAS between January 2022 and July 2025. Comprehensive clinical, imaging, pharmacogenomic, and thromboelastography (TEG) data were collected. ISR was defined as ≥50% luminal narrowing within or at its margins during follow-up. Risk factors for ISR were analyzed using univariate and multivariate logistic regression models. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of age, smoking, hypertension, stent tortuosity, CYP2C19 poor metabolizer status and TEG parameters for patients with ISR. RESULTS: Of the 223 patients with complete follow-up data, 28 (12.56%) developed ISR within one year. Univariate analysis identified age, hypertension, smoking, stent tortuosity, CYP2C19 poor metabolizer status and elevated TEG parameters (α-Angle and MA value) as significantly associated with ISR. Multivariate analysis confirmed that α-Angle (OR 1.215, 95% CI 1.025-1.441, p = 0.025) and MA value (OR 1.249, 95% CI 1.025-1.522, p = 0.027) were independent predictors of ISR. ROC analysis demonstrated excellent predictive performance of α-Angle (AUC 0.826) and MA (AUC 0.814) for ISR risk stratification. CONCLUSION: ISR remains a significant clinical challenge after DES implantation for OVAS. A combination of clinical, genetic and coagulation factors contributes to its development. TEG parameters, particularly α-Angle and MA, provide valuable predictive information. These findings support the integration of individualized antiplatelet strategies and TEG-guided monitoring to optimize outcomes in OVAS patients.