Early Drug-Eluting Stent Restenosis Due to Aggressive Neoatherosclerotic Degeneration, an Optical Coherence Tomography Finding

Abstract

We report a case of unusually early in-stent restenosis in a drug-eluting stent due to likely aggressive neoatherosclerotic degeneration.

Case report

A 62-year-old female patient with a history of diabetes mellitus, morbid obesity (BMI 38) and hypercholesterolemia presented with unstable angina. Three months earlier, the patient had a successful and uncomplicated percutaneous revascularization of a chronic total occlusion (CTO) of the left anterior descending (LAD) coronary artery with implantation of two minimally overlapping everolimus-eluting stents (total stent length 66 mm). Repeated coronary angiography revealed severe focal near-occlusive in-stent restenosis (ISR), exactly at the site of the original occlusion, where aggressive wire manipulation had been performed during initial CTO recanalization. Optical coherence tomography (OCT) at the restenotic site showed severe intimal hyperplasia, areas of low-intensity signal compatible with collagen-poor tissue, and evidence of atheromatous neointimal degeneration.¹ An active inflammatory process was suggested by accumulations of macrophages. In a more proximal part of the stented segment, layers of signal-poor tissue at the inner lumen border, compatible with fibrin deposition around stent struts, were observed, as well as multiple regions with extensive calcification (low backscattering zones with sharp demarcation from the overlying higher backscattering fibrous tissue).¹ Following discussion, percutaneous revascularization with aggressive secondary prevention was elected as the preferred treatment. The ISR was treated with aggressive predilatation using a non-compliant balloon at high pressure, followed by the use of a cutting balloon to adequately prepare the lesion. A paclitaxel-eluting balloon (SeQuent Please, B-Braun) was successfully applied with an excellent angiographic result. Drug-eluting balloons, a relatively new technology, have been proposed as an attractive treatment alternative for ISR. With preserved clinical efficacy compared to the use of DES, the main advantage of this technology is the avoidance of the application of a second layer of metal in the diseased coronary artery segment, possibly leading to better vessel wall healing and a better safety profile.^2-3

Although the risks of ISR in this case were high in view of the lesion characteristics, patient characteristics and length/number of DES implanted, an underlying mechanism of exclusively extensive neointimal hyperplasia would have been anticipated. The OCT appearances in this case are however, consistent with a neoatherosclerotic process. In-stent neoatherosclerosis has been recognized as a frequent cause of ISR, occurring more frequently and at an earlier stage after implantation of DES compared with BMS (mean 420 days in DES vs. 2160 days in BMS in a human pathology series).⁴ Recent evidence suggests coronary stenting results in persistent inflammation and abnormalities of endothelial function, which may result in stent failure and restenosis.⁵ The unusually early (at 98 days after percutaneous intervention) and aggressive development of neoatheromatous degeneration in this case might have been stimulated by extensive vessel wall trauma during the initial CTO procedure, provoking a strong inflammatory reaction in a “high risk” diabetic hyperlipidemic environment. Histological studies would be helpful to characterize the exact nature and possible differences between early, such as in this case, and later neoatherosclerotic processes in DES ISR. A better understanding of the involved process would lead to informed clinical decision making and improved device selection, ultimately improving the safety and efficacy of intracoronary stents.

This article received a double-blind peer review from members of the Cath Lab Digest editorial board. Disclosure: The authors report no financial relationships or conflicts of interest regarding the information herein. 

The authors may be contacted via Dr. Johan Bennett at johan.bennett@uzleuven.be.

References 

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