BACKGROUND: Arterial repair in the early phase following implantation of a zotarolimus-eluting stent (ZES) remains unknown. METHODS AND RESULTS: Following implantation of 49 Endeavor ZES in 33 patients, follow-up angioscopy was performed in 13 patients (26 ZES) in the early phase (EP; 123±24 days) and in 20 patients (23 ZES) in the middle phase (MP; 247±17 days). Neointimal coverage (NIC) was graded as follows: grade 0, stent struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts were embedded by the neointima but were seen translucently; grade 3, struts fully embedded and invisible. NIC was defined as heterogeneous for NIC grade variation≥1. The presence of thrombus and yellow plaque was also investigated. Although NIC heterogeneity tended to be more frequent in EP than in MP (50% vs. 22%, P=0.070), and yellow plaque significantly more frequent (58% vs. 13%, P=0.0025), the majority of stents were dominant NIC grade 3 at both follow-up periods (73% in EP vs. 78% in MP, P=0.75). There was no significant difference in thrombus (23% in EP vs. 4% in MP, P=0.10) between the follow-ups. CONCLUSIONS: Sufficient arterial repair may have occurred by 4 months after ZES implantation.
BACKGROUND: Arterial repair in the early phase following implantation of a zotarolimus-eluting stent (ZES) remains unknown. METHODS AND RESULTS: Following implantation of 49 Endeavor ZES in 33 patients, follow-up angioscopy was performed in 13 patients (26 ZES) in the early phase (EP; 123±24 days) and in 20 patients (23 ZES) in the middle phase (MP; 247±17 days). Neointimal coverage (NIC) was graded as follows: grade 0, stent struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts were embedded by the neointima but were seen translucently; grade 3, struts fully embedded and invisible. NIC was defined as heterogeneous for NIC grade variation≥1. The presence of thrombus and yellow plaque was also investigated. Although NIC heterogeneity tended to be more frequent in EP than in MP (50% vs. 22%, P=0.070), and yellow plaque significantly more frequent (58% vs. 13%, P=0.0025), the majority of stents were dominant NIC grade 3 at both follow-up periods (73% in EP vs. 78% in MP, P=0.75). There was no significant difference in thrombus (23% in EP vs. 4% in MP, P=0.10) between the follow-ups. CONCLUSIONS: Sufficient arterial repair may have occurred by 4 months after ZES implantation.