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World J Cardiol. Nov 26, 2015; 7(11): 776-783
Published online Nov 26, 2015. doi: 10.4330/wjc.v7.i11.776
Neoatherosclerosis: Coronary stents seal atherosclerotic lesions but result in making a new problem of atherosclerosis
Hidenori Komiyama, Masamichi Takano, Noritake Hata, Yoshihiko Seino, Wataru Shimizu, Kyoichi Mizuno
Hidenori Komiyama, Masamichi Takano, Noritake Hata, Yoshihiko Seino, Cardiovascular Center, Chiba Hokusou Hospital, Nippon Medical School, Chiba 270-1613, Japan
Wataru Shimizu, Cardiology, Nippon Medical School, Tokyo 113-0022, Japan
Kyoichi Mizuno, Mitsukoshi Health and Welfare Foundation, Tokyo 160-0023, Japan
Author contributions: Komiyama H wrote the manuscript; Takano M provided advice and revised the manuscript; Hata N, Seino Y, Shimizu W, and Mizuno K also provided intellectual advice.
Conflict-of-interest statement: The authors declare no conflicts of interests related to this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Masamichi Takano, MD, Cardiovascular Center, Chiba Hokusou Hospital, Nippon Medical School, 1715 Kamakari, Inzai, Chiba 270-1613, Japan. takanom@nms.ac.jp
Telephone: +81-476-991111 Fax: +81-476-991908
Received: June 3, 2015
Peer-review started: June 7, 2015
First decision: June 18, 2015
Revised: July 21, 2015
Accepted: September 16, 2015
Article in press: September 18, 2015
Published online: November 26, 2015
Processing time: 179 Days and 13 Hours
Abstract

Chronic inflammation of the native vessel wall with infiltration of lipid-laden foamy macrophages through impaired endothelium results in atherosclerosis. Percutaneous coronary intervention, including metallic stent implantation, is now widely utilized for the treatment of atherosclerotic lesions of the coronary artery. Bare-metal stents and the subsequently developed drug-eluting stents seal the atherosclerosis and resolve lumen stenosis or obstruction of the epicardial coronary artery and myocardial ischemia. After stent implantation, neointima proliferates within the stented segment. Chronic inflammation caused by a foreign body reaction to the implanted stent and subsequent neovascularization, which is characterized by the continuous recruitment of macrophages into the vessel, result in the transformation of the usual neointima into an atheromatous neointima. Neointima with an atherosclerotic appearance, such as that caused by thin-cap fibroatheromas, is now recognized as neoatherosclerosis, which can sometimes cause in-stent restenosis and acute thrombotic occlusion originating from the stent segment following disruption of the atheroma. Neoatherosclerosis is emerging as a new coronary stent-associated problem that has not yet been resolved. In this review article, we will discuss possible mechanisms, clinical challenges, and the future outlook of neoatherosclerosis.

Keywords: Neoatherosclerosis; Percutaneous coronary intervention; Drug-eluting stent; Atherosclerosis

Core tip: Percutaneous coronary intervention, including metallic stent implantation, causes chronic inflammation of the coronary artery and neovascularization, which involves the continuous recruitment of macrophages into the vessel. The phenomenon of stent neointima transformation from normal neointima to atherosclerotic lesions is now recognized as neoatherosclerosis, which causes in-stent restenosis and acute thrombotic occlusion. Neoatherosclerosis is now emerging as a new atherosclerosis-related problem that has not yet been solved. In this review, we will discuss possible mechanisms, clinical challenges, and the future outlook of neoatherosclerosis.