CHARACTERISTICS OF VESSEL WALL REMODELING AFTER ENDOVASCULAR CORRECTION OF LONG CORONARY LESIONS: OPTICAL COHERENCE TOMOGRAPHY FINDINGS
Authors: Nikolai Strygo , Valeriy Stelmashok , Oleg Polonetsky , Andrei Zatsepin , Andrei Zakharevich , Andrei Buryi , Irina Tataritskaya , Ludmila Sapun 
Published: September 2024

Aim. To examine the mechanisms of coronary artery vessel wall remodeling based on the analysis of the results of optical coherence tomography after correction of long coronary lesions. Material and methods. This study includes 80 patients who underwent endovascular correction of long (more than 25 mm) coronary lesions at the Republican Scientific and Practical Centre "Cardiology". The patients were randomly divided into two groups: the main group (MG) of 40 patients - lesions correction with biodegradable vascular scaffolds BVS Absorb and the control group (CG) of 40 patients - correction of lesions with drug-eluting metal stent Xience V/Xience Pro. Results. In OCT study after implantation procedure, the lumen area inside the stent/scaffold was statistically different between groups and was 6.89±1.93 mm2 in the main group and 8.33±2.94 mm2 in the control group. At the 12-month follow-up, there was a significant decrease in the lumen area in the main and control groups: to 6.13±2.30mm2 and 7.72±3.11mm2, respectively. Analysis of implant fragments revealed a significant difference in the incidence of struts malposition between the MG and CG both initially (1.29% versus 1.56%) and at 12-month follow-up (0.19% versus 0.38% in the control group). The number of protruding struts, in turn, was significantly higher in the main group (2.26% versus 0.14%). There was a significant difference in mechanisms of stents/scaffolds neointimal coverage at the 12-month control: the neointima was more smoothly distributed in the main group with minimum thickness of 50 µm versus 40 µm in control, while the incidence of uncovered struts was significantly lower in the main group than in the control group - 1.26% versus 12.6%. In both groups, the development of evaginations of the vascular wall at the site of implantation was revealed with significant differences between the groups: in the control group, 2 such patients (5%) were identified with a total volume of evaginations of 5.4 mm3 and a maximum depth of up to 0.58 mm, while in the MG there was 12 such patients (30%) with a total volume of evaginations of 148.3 mm3 and a maximum depth of up to 1.64 mm. Moreover, one patient from the main group with the maximum volume, number and depth of evaginations, the only one in the entire sample had definite thrombosis in the scaffold. Conclusion. Scaffolds Absorb BVS have smoother and more complete neointimal coverage at 12-month follow-up compared to Xience V/Xience Pro metal stents. At the same time, arteries at the sites of implantation of Absorb BVS scaffolds have a significantly greater tendency to form big protrusions of the vascular wall - evaginations. The formation of these evaginations can explain greater tendency to thrombosis of the coronary arteries in the area of implanted device. With scaffold degradation the number and volume of evaginations decreases, so we can expect a decrease in the number of possible negative outcomes.