Background Drug-eluting stents effectively reduce restenosis but may increase late thrombosis and delayed restenosis. Persistent polymer, the drug, or a combination of both could be responsible.
Objective To study the effect of endothelial progenitor cell (EPC) capture on the vascular response to polymer-free SIROLIMUS- eluting stent (PFSES). This combo stent may reduce neointimal proliferation and address the risk of stent thrombosis by facilitating rapid endothelialisation compared with the permanent-polymer sirolimus-eluting stent (SES) or PFSES alone.
Methods We compared a combo stent (CS), a polymer-free sirolimus-eluting stent coated with anti-CD34 antibody, with a permanent-polymer sirolimus-eluting stent (SES), a polymer-free sirolimus-eluting stent (PFSES) and a bare-metal stent (BMS) at 14 days and 28 days in a porcine model with optical coherence tomography (OCT) and histological analysis.
Results At 14 days, via OCT evaluation, there was a reduction in neointimal proliferation by CS and PFSES compared with SES and BMS (neointimal thickness: BMS, 0.44 ± 0.12; SES, 0.42 ± 0.03; PFSES, 0.14 ± 0.11; CS, 0.11 ± 0.06; P < 0.005; BMS/SES > CS/PFSES). At 28 days, both CS and PFSES were associated with reduced neointimal proliferation, whereas SES exhibited increased neointima (neointimal thickness: BMS, 0.62 ± 0.11; SES, 0.63 ± 0.08; PFSES, 0.18 ± 0.06; CS, 0.21 ± 0.06; P < 0.005; BMS/SES > CS/PFSES). The histology evaluation was demonstrated the similar results. At 14days and 28 days, combo stent showed decreased fibrin and inflammation, compared with SES and PFSES. In addition, the combo SES is associated with increased endothelium-dependent relaxation, protected vascular Endothelial Function.
Conclusions The polymer-free sirolimus-eluting stent modified with anti-CD34 antibody demonstrates equivalent early and superior late reduction of intimal proliferation compared with SES in a porcine model. After implantation of combo stent, delayed arterial healing was minimal, and there was no increased inflammation at 28 days compared with SES implantation. The use of combo stents may have a potential short-term benefit over traditional polymeric-coated drug-eluting stents.