Very late-phase vascular response after everolimus-eluting stent implantation assessed by optical coherence tomography.

Long-term safety of second generation drug-eluting stents (DES) has not yet been evaluated. We sought to evaluate the very late phase (> 3 years) vascular response after second generation everolimus-eluting stent (EES) as compared with first generation sirolimus-eluting stent (SES) by using optical coherence tomography (OCT). We examined the vascular response in 39 patients with a total of 55 DESs [31 EESs (mean 54 months after stenting) and 24 first generation SES (mean 66 months after stenting)] by OCT. The frequency of lesions with any malapposed stent struts (19% vs. 46%, p = 0.035) and evagination (6% vs. 42%, p = 0.002) was significantly lower. Segments with malapposed stent struts were significantly shorter (0.4 ± 0.9 mm vs. 1.9 ± 3.5 mm, p = 0.024), maximal malapposition area and malapposition volume were significantly smaller (0.26 ± 0.38 mm2 vs. 0.95 ± 1.54 mm2, p = 0.019, and 0.78 ± 1.35 mm3 vs. 6.22 ± 15.76 mm3, p = 0.016, respectively) in EES. Compared with first generation SES, second generation EES showed more favourable vascular responses at the very late phase.