Long-Term Follow-up of a Coronary Artery Aneurysm After Biodegradable-Polymer Sirolimus-Eluting Stent Implantation

A 46-year-old man with dyslipidemia presented with exertional angina. He had no history of collagen disease. Coronary angiography (CAG) demonstrated total occlusion of the right coronary artery (RCA) (Figure A). Biodegradable-polymer sirolimus-eluting stents (BP-SES; Ultimaster; Terumo Corporation, Tokyo, Japan) were successfully implanted in the lesion, although dissection at the stent proximal edge was seen (Figure B). Postoperatively, intravascular ultrasound showed well-apposed struts and no dissections at other stenting sites (Figure C).

Figure.

(A) Baseline coronary angiography (CAG). (B) CAG after biodegradable-polymer sirolimus-eluting stent implantation showing dissection at the stent proximal edge (arrowhead). (C-a–c) Intravascular ultrasound after the procedure shows well-apposed struts and no dissections at the other stenting sites shown in (B). Follow-up CAG at (D) 6 months shows coronary artery aneurysms (CAAs) in the stented area (arrowheads), with partial improvement at (E) 12 months and (F) 30 months. (G) Optical coherence tomography at 30 months at sites shown in (F). Struts in the improved section are completely covered with neointimal tissue (a), but are incompletely covered and malapposed in the residual CAAs (b).

At 6 months’ postoperatively, follow-up CAG revealed coronary artery aneurysms (CAAs) in the stented area (Figure D). Serial CAG at 12 and 30 months showed that the CAAs had partially improved (Figures E,F). Optical coherence tomography demonstrated that struts in the improved portion were completely covered with neointimal tissue (Figure G-a), whereas struts in the residual CAAs were incompletely covered and malapposed (Figure G-b).

To our knowledge, this is the first report of long-term follow-up of CAAs after BP-SES implantation. Although the exact mechanism of CAA formation is unknown, inflammatory or hypersensitivity reactions to the drug and polymer are considered to play a crucial role in CAA formation.¹ The BP-SES has a biodegradable polymer that is resorbed, and it releases sirolimus within 3–4 months. Interestingly, the serial follow-up CAG demonstrated that CAAs developed within 6 months and partially improved after 6 months. These findings may reflect inflammatory or hypersensitivity reactions to the drug and polymer, not the healing state of coronary dissections.

Disclosures

K.K. is a member of Circulation Journal’s Editorial Team. This study followed the Declaration of Helsinki.

Reference

• 1.   Cook S, Wenaweser P, Togni M, Billinger M, Morger C, Seiler C, et al. Incomplete stent apposition and very late stent thrombosis after drug-eluting stent implantation. Circulation 2007; 115: 2426–2434.