Impact of coronary calcifications 12 months after everolimus-eluting stent implantation: an optical coherence tomography study

To assess the endothelial coverage and neointimal proliferation at 12 months after everolimus-eluting stent (EES) implantation in patients with coronary calcifications by optical coherence tomography (OCT). Seventeen patients who received an EES in culprit coronary lesions of acute coronary syndrome (ACS) underwent follow-up OCT examination at 12 months. Eleven patients in whom spotty calcifications were detected in stent segment vessels by OCT were included in the final analysis. The percentage of uncovered struts (6.0 vs. 2.0%, P < 0.001) and the stent symmetry index (0.883 ± 0.040 vs. 0.913 ± 0.026, P = 0.018) differed significantly between cross sections of EESs over calcified lesions (calcium cross sections) and those over lesions without calcification (non-calcium cross sections). In addition, in calcium cross sections, the neointimal thickness differed significantly between struts over lesions with (calcium struts) and without calcification (non-calcium struts; 138 ± 65 vs. 99 ± 60 μm, P = 0.006). Cross-sectional OCT images of EESs implanted at sites of calcification in ACS patients showed more uncovered struts, and a worse stent symmetry index, compared with those of EESs implanted at sites without calcification. In calcium cross sections, calcium struts had greater neointimal thickness than non-calcium struts. Future prospective in vivo studies are required to validate the relationship between the findings in this study and clinical events.