Serial (median 270 days and median 551 days after stent implantation) optical coherence tomography (OCT) examinations were performed in 42 stented lesions from 26 patients. In-stent neointimal tissue was categorized as either homogeneous or heterogeneous neointima based on the OCT appearance at 1st follow-up. Serial changes in neointimal area (NIA) were compared between lesions with homogeneous neointima and those with heterogeneous neointima.
At first follow-up, homogeneous neointima was observed in 22 (52%) and heterogeneous neointima in 20 (48%) lesions, respectively. During follow-up, NIA in lesions with homogeneous neointima decreased significantly (1.8 ± 0.93 mm2 to 1.5 ± 0.88 mm2, p < 0.001). On the other hand, NIA in lesions with heterogeneous neointima did not change significantly (2.7 ± 1.8 mm2 to 2.8 ± 1.6 mm2, p = 0.658). Homogeneous neointima was the only predictor of late neointimal regression (late neointimal regression defined as NIA at first follow-up – NIA at second follow-up <0) by multivariable analysis (odds ratio = 7.591, 95% confidence interval: 1.616–35.67, p = 0.010).
OCT characteristics of neointima after DES implantation may be related to late neointimal progression or regression.