Optical coherence tomographic observation of in-stent neoatherosclerosis in lesions with more than 50% neointimal area stenosis after second-generation drug-eluting stent implantation

Background-Despite the enhanced properties of the second-generation drug-eluting stent (DES), its association with neoatherosclerosis has not been sufficiently evaluated. Therefore, we sought to evaluate and compare neoatherosclerosis in second-generation DESs to first-generation DESs. Methods and Results-A total of 212 DES-treated patients with >50% percent neointimal cross-sectional area stenosis were retrospectively enrolled from the Korean multicenter optical coherence tomography (OCT) registry. Within this population, 111 patients had a second-generation DES (40 zotarolimus, 36 everolimus, and 35 biolimus) and 101 patients had a firstgeneration (65 sirolimus and 36 paclitaxel) DES. Neoatherosclerosis on OCT was defined as neointima formation with the presence of lipids or calcification. OCT-determined neoatherosclerosis was identified in 27.4% (58/212) of all DES-treated lesions. The frequency of neoatherosclerosis increased with the stent age. Stent age was shorter in the secondgeneration DES group (12.4 months versus 55.4 months, P<0.001), and neoatherosclerosis was less frequently observed in that group (10.8% versus 45.5%, P<0.001). However, after adjusting for cardiovascular risk factors, chronic kidney disease (odds ratio, 4.113; 95% confidence interval, 1.086-15.575; P=0.037), >70 mg/dL of low-density cholesterol at follow-up OCT (odds ratio, 2.532; 95% confidence interval, 1.054-6.084; P=0.038), and stent age (odds ratio, 1.710; 95% confidence interval, 1.403-2.084; P<0.001) were all independent predictors for neoatherosclerosis, whereas the type of DES (first-versus second-generation) was not. Patients with neoatherosclerosis showed a higher rate of acute coronary syndrome at follow-up OCT (19.0% versus 3.9%, respectively, P=0.001). Conclusions-The second-generation DES is not more protective against neoatherosclerosis compared with the firstgeneration DES.