Contribution of Poststent Irregular Protrusion to Subsequent In-Stent Neoatherosclerosis after the Second-Generation Drug-Eluting Stent Implantation Optical Coherence Tomography Study

Previous optical coherence tomography (OCT) study reported that irregular protrusion (IP) post drug-eluting stent (DES) implantation was an independent predictor of clinical outcome; however, the relationship between IP and the presence of subsequent in-stent neoatherosclerosis remains unclear. This study aimed to assess the relationship between IP and in-stent neoatheroscrerosis formation using OCT. We evaluated 83 patients (101 lesions) who underwent second-generation DES implantation and 8-month follow-up (8M-FU) using OCT. Lesions were divided into two groups in presence of IP (IP: n = 43, non-IP: n = 58). At prepercutaneous coronary intervention (pre-PCI), lipid-rich plaque, lesions with positive remodeling, and in-stent thrombus formation were more frequent in IP than in non-IP. On multivariate analysis, the thrombus at pre-PCI and the lesions with positive remodeling were independent predictors of IP. At 8M-FU, heterogeneous neointima, microvessel, lipid-laden neointima, and thin-cap fibro-atheroma like neointima were more frequent in IP than in non-IP (respectively, P < 0.05). On multivariate analysis, IP was associated with heterogeneous neointima. Binary restenosis was more frequent and late lumen loss tended to be larger in IP than in non-IP (19% versus 5%, P = 0.04; 1.25 +/- 1.24 mm versus 0.91 +/- 0.63 mm, P = 0.09); however, the target lesion revascularization rate was similar in both groups at 8M-FU. In conclusion, our study suggested that poststent IP was associated with subsequent neoatherosclerosis formation at 8M-FU after the second-generation DES implantation.