<p><strong>Aim.</strong> To examine the process of neointimal formation after bioresorbable scaffolds (BRS) implantation using optical coherence tomography (OCT) in patients with stable coronary artery disease (SCAD) and to determine relationship between neointimal healing and biochemical parameters of inflammation.<br /><strong>Methods.</strong> Patients with SCAD (n = 20) who were indicated for percutaneous coronary intervention (PCI) were enrolled. Patients were randomised into two groups as per the stent type. The treatment group comprised 10 patients who were implanted with BRS ABSORB (Abbott Laboratories, Abbott Park, USA) during PCI. The comparison group comprised 10 patients who were implanted with DES XIENCE (Abbott Laboratories, Abbott Park, USA) during PCI. All the patients underwent OCT imaging during PCI. Subsequently, 18 patients were subjected to coronary angiography with OCT imaging in 12 mon. The primary endpoint was the 12-month neointimal healing (NIH) score. Secondary endpoints were clinical outcomes (all-cause hospitalisation, myocardial infarction, probable stent thrombosis and death), OCT parameters at the 12-month follow-up and biochemical markers dynamics.<br /><strong>Results.</strong> Initial angiographic data analysis indicated a higher rate of balloon pre-dilatation (100% vs. 30%; р = 0,003) and post-dilatation (100% vs. 20% р = 0,001) in patients of the treatment group. According to OCT, the NIH score was significantly higher in the XIENCE group [0 versus 9,14 (1,63–17,55); р = 0,008] at 12 mon. There was no significant difference in the clinical outcomes between the two groups. However, the ABSORB group had an increased CD40 level after 4–5 d of PCI. In agreement with the results of correlation analysis, there was an inverse correlation between the NIH score and CD40 level at 4–5 d after PCI (r = −0,576; р = 0,016). The cut-off value of CD40 level at 4–5 d after PCI was 47,5 ng/mL for the detection of optimal neointimal healing.<br /><strong>Conclusion.</strong> In patients with SCAD, BRS demonstrated higher rate of neointimal healing than everolimus-coated stents. There was a registered inverse correlation of the NIH score with the CD40 level at 4–5 days after PCI. CD40 level > 47,5 ng/mL at 4–5 d after PCI increases the likelihood of optimal neointimal healing as per OCT data.</p><p>Received 19 February 2021. Revised 7 June 2021. Accepted 16 June 2021.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> The authors declare no conflicts of interests.</p><p><strong>Contribution of the authors</strong><br />Conception and study design: I.S. Bessonov, N.A. Musikhina, T.I. Petelina<br />Data collection and analysis: S.S. Sapoznikov, I.S. Bessonov, N.А. Galeeva, A.O. Dyakova<br />Statistical analysis: S.S. Sapoznikov, E.A. Gorbatenko<br />Drafting the article: S.S. Sapoznikov, N.А. Galeeva, A.O. Dyakova<br />Critical revision of the article: I.S. Bessonov, S.S. Sapoznikov, E.A. Gorbatenko, N.A. Musikhina<br />Final approval of the version to be published: S.S. Sapoznikov, N.А. Galeeva, I.S. Bessonov, N.A. Musikhina, T.I. Petelina, A.O. Dyakova, E.A. Gorbatenko</p>