A serial 3- and 9-year optical coherence tomography assessment of vascular healing response to sirolimus- and paclitaxel-eluting stents

Early-generation drug-eluting stents (DES) have been demonstrated to delay vascular healing. Limited optical coherence tomography (OCT) data on the very long-term neointimal response after DES implantation are available. The aim of this study was a serial OCT assessment of neointimal thickness, stent strut coverage, malapposition, and protrusion as markers of neointimal response at 3 and 9 years after implantation of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES). In this single-centre, longitudinal study consecutive patients undergoing elective PCI with SES or PES were included. OCT analysis was performed after 3 and 9 years by the independent core laboratory. A total of 22 subjects (8 SES and 14 PES) underwent an OCT assessment at 3 and 9 years post index procedure. The lumen, neointimal and malapposition area and the neointimal thickness (SES ∆50 µm, p = 0.195, PES ∆10 µm, p = 0.951) did not change significantly over the 6 year follow-up. No differences in the incidence of uncovered, malapposed or protruding struts were found in each type of stent. At 3 and 9 years after PCI, implantation of early-generation SES and PES may be associated with similar neointimal thickness, strut coverage, malapposition and protrusion, as assessed by serial OCT examination among patients with uneventful follow-up at 3 years post procedure. The small size of the study warrants judicious interpretation of our results and confirmation in larger multimodality imaging studies, including patients treated with contemporary stent platforms.