Determinants of neointimal proliferation and stent coverage after intracoronary therapy with drug-eluting devices in stable coronary artery disease: role of endothelial progenitor cells and interleukin-1 family cytokines.

Abstract Endothelial progenitor cells (EPCs) and cytokines seem to play a pivotal role in arterial healing after stent implantation. Using optical coherence tomography (OCT) as a high-resolution imaging technique, we aimed to assess the influence of circulating EPCs and levels of Il-1 cytokines on stent coverage and in-stent proliferation. Eighty-nine patients were randomly treated with either Xience V drug-eluting stent (DES; n = 48) or bare-metal stent (BMS) postdilated with the SeQuent Please drug-eluting balloon (DEB; n = 41). EPC populations (CD34+/CD133+ and CD34+/CD133+/KDR+ EPC) and cytokines (Il-1ra, Il-18, and Il-1α) were measured before percutaneous coronary intervention using flow cytometry or immunoassay. Vessel remodeling was analyzed using coronary angiography and OCT at 6-month follow-up. Indexed neointimal volume and maximal proliferation thickness correlated inversely with EPC levels in the entire study population (r = -0.220; P=.04 and r = -0.253; P=.02) and the BMS + DEB subgroup (r = -0.344; P=.03 and r = -0.374; P=.02). Late lumen loss (LLL) was associated with the proatherogenic Il-18 concentration in the main population (r = 0.342; P=.01) and the BMS + DEB group (r = 0.471; P=.01). In the DES subgroup, associations with proliferation and LLL were lacking. Associations for stent strut coverage were not observed. A high EPC count seems to be a favorable individual patient factor, since it was associated with less instent proliferation. Contrarily, high Il-18 levels lead to more LLL, which emphasizes its proatherogenic properties.