Characteristics of early versus late in-stent restenosis in second-generation drug-eluting stents: an optical coherence tomography study

In-stent restenosis (ISR) is an important cause of drug-eluting stent (DES) failure and target vessel revascularisation. In this study we aimed to evaluate differences between early and late-presenting restenosis in second-generation DES using optical coherence tomography (OCT).Overall, 171 cases of second-generation DES ISR with a follow-up OCT minimum lumen area3.0 mm2 were included: 33.3% of patients (n=57) had early ISR, and 66.7% (n=114) had late ISR (duration from stent implantation1 year). Minimum stent area (MSA)4.0 mm2, neointimal thickness100 µm, and heterogeneous neointimal hyperplasia (NIH) were more prevalent in early ISR, whereas NIH with neoatherosclerosis trended towards being more frequent for late ISR (28.9% vs. 15.8%, p=0.06). Multivariable analysis revealed that duration from implantation2 years, absence of statin use, and NIH50% were independent predictors for neoatherosclerosis (all p0.05).OCT morphological characteristics of second-generation DES ISR differ between early and late presentation. Early ISR was associated with MSA4.0 mm2, while neoatherosclerosis contributed more commonly to late ISR.