Angioscopy of In-Stent Restenosis After Second-Generation Drug-Eluting Stent Implantation　― Three High-Resolution Coronary Angioscopy Observations ―

Although drug-eluting stents (DES) have drastically reduced the incidence of in-stent restenosis (ISR), managing patients with DES-ISR remains a challenging issue. Alfonso et al noted that intracoronary imaging tools provide unique insights into the underlying etiology of DES-ISR,¹ but few studies have used coronary angioscopy (CAS) to directly observe the intracoronary status of DES-ISR.

Herein, we present three different observations of newer generation DES-ISR using cutting-edge CAS (Figure).

Figure.

Coronary (Upper) angiography and (Lower) angioscopy. In-stent restenosis (ISR) of (A,a) a cobalt-chrome everolimus-eluting stent (Xience^®; x, red thrombi); (B,b) a cobalt-chrome sirolimus-eluting stent (Ultimaster^®; +, neointimal hyperplasia); and (C,c) a slow-release zotarolimus-eluting stent (Resolute^TM; *, small calcified nodules protruding into the lumen). Yellow triangles, ISR.

Observation 1: ISR of a cobalt-chrome everolimus-eluting stent (Xience^®) 30 months after implantation (Figure A,a). Post-thrombectomy CAS shows barely visible stent struts attached to numerous red thrombi (x) and glittering yellow plaque below the stent. This was regarded as very late stent failure.

Observation 2: ISR of a cobalt-chrome sirolimus-eluting stent (Ultimaster^®) 12 months after implantation (Figure B,b). CAS shows many invisible fully embedded struts, several visible embedded stent struts, and neointimal hyperplasia (NIH; +). NIH overexpression caused the ISR.

Observation 3: ISR of a slow-release zotarolimus-eluting stent (Resolute^TM) 6 months after implantation (Figure C,c). CAS shows many invisible embedded and several visible embedded stent struts. Small calcified nodules protrude into the lumen (*). In this case, the ISR was thought to be due to developing calcified nodules.

The cutting-edge CAS system yields 9,000-pixel (Forwardlooking^®, Ovalis, Osaka, Japan), high-resolution images, resulting in better visible intracoronary fields for the detection of NIH, yellow-colored plaque and thrombus, thereby enabling better clarification of the mechanisms of DES-ISR.

Disclosures

The authors declare no conflicts of interest.

Reference

• 1.   Alfonso F, Byrne RA, Rivero F, Kastrati A. Current treatment of in-stent restenosis. J Am Coll Cardiol 2014; 63: 2659–2673.