Vascular Remodeling Using Different Types of Stents in Non-ST Elevation Acute Coronary Syndrome: OCT Study

Introduction . The wide variety of drug-eluting stents used to treat acute coronary syndrome necessitates comparative studies of vascular healing processes after their implantation. Of particular interest is the nature of neointimal formation and its relationship to stent design features. Objective . To evaluate neointimal healing parameters after implantation of different types of drug-eluting stents in patients with non-ST-segment elevation acute coronary syndrome and to identify factors influencing vascular remodeling. Materials and Methods . This prospective study included 111 patients with non-ST-segment elevation acute coronary syndrome after implantation of different types of drug-eluting stents. Depending on the type of stent implanted, the patients were divided into 4 groups: Group 1 – a cobalt-chromium stent with permanent polymer and everolimus; Group 2 – a platinum-chromium stent with bioabsorbable polymer and everolimus; Group 3 – a cobalt-chromium stent with bioabsorbable coating and sirolimus; Group 4 – a platinum-chromium stent with permanent polymer and everolimus. The patient groups were comparable in terms of key clinical and demographic parameters. For quantitative assessment of healing, optical coherence tomography (OCT) was performed in all patients after 4.3±2.3 months. A total of 54,195 struts in 111 stents were analyzed by OCT. The key evaluation criterion was the calculated «healing index». Results . Statistically significant differences were found between the groups: the highest healing index (p=0.004) and the highest number of uncovered stent struts (p=0.009) were observed in the group with platinum-chromium stents with a bioabsorbable coating. Furthermore, malapposed stent struts were more common in the groups with bioabsorbable coatings (p=0.002). Multivariate regression analysis revealed that independent predictors of the healing index were age (p=0.0006), stent diameter (p=0.003), a long history of arterial hypertension (p=0.04), and dyslipidemia (p=0.006). Further analysis demonstrated that age, hypertension, and dyslipidemia were primarily associated with the number of uncovered struts, whereas stent diameter correlated mainly with the percentage of malapposed struts. Conclusions . The degree of vascular remodeling after drug-eluting stent implantation for acute coronary syndrome does not demonstrate a fundamental relationship with the type of stent platform. Non-modifiable (age, stent diameter) and modifiable (hypertension, dyslipidemia) risk factors have the most significant impact on vascular healing, highlighting the importance of systematic cardiovascular risk management in addition to the choice of interventional strategy.