Very Late Stent Thrombosis 89 Months after Implantation of Durable Polymer Everolimus-Eluting Stent due to Late Acquired Stent Malapposition and Uncovered Struts Observed by Optical Coherence Tomography, Near-Infrared Spectroscopy and Coronary Angioscopy

Abstract

Very late stent thrombosis (VLST) is a potentially life-threatening complication in coronary angioplasty patients. The patient was a 95-year-old man who had been implanted with a durable polymer everolimus-eluting stent (DP-EES, 3.5 × 23 mm) at the restenosis site in the proximal part of the left descending artery using only plain balloon angioplasty for acute coronary syndrome (ACS) 27 months earlier. Final intravascular ultrasound (IVUS) evaluation had shown no stent malapposition and adequate stent expansion. However, he presented to our hospital due to vomiting and fatigue 89 months after the implantation. An electrocardiogram showed ST-elevation in V2-6 leads, we therefore suspected ACS and emergent coronary angiography (CAG) revealed total occlusion of DP-EES site, which was diagnosed as VLST. Percutaneous coronary intervention (PCI) was subsequently carried out and complete recovery of blood flow was obtained by thrombus aspiration. Optical coherence tomography (OCT) demonstrated uncovered struts, stent malapposition, and some thrombi in the proximal part of DP-EES. Yellow chemogram was not detected in the DP-EES site by near-infrared spectroscopy (NIRS). Coronary angioscopy (CAS) showed exposed stent struts with red thrombus adhesion in the proximal part of the DP-EES. Judging from intravascular images, the main cause of VLST was stent malapposition and uncovered struts. Here, we report a case with VLST due to late acquired stent malapposition and uncovered struts 89 months after DP-EES implantation.