Nine-Month Angiographic and Intravascular Ultrasound Outcomes After Resolute Zotarolimus-Eluting Stent Implantation for the Treatment of In-Stent Restenosis

Objectives We aimed to evaluate the mid‐term outcomes of resolute zotarolimus‐eluting stent (R‐ZES) implantation for in‐stent restenosis (ISR). Background There has been a paucity of data regarding the effects of new‐generation drug‐eluting stent to treat ISR. Methods From 2009 to 2010, a total of 98 patients with 98 ISR lesions were prospectively enrolled after R‐ZES implantation for the treatment of ISR. Among 98 patients, 73 patients underwent follow‐up angiography at 9 months. Serial intravascular ultrasound (IVUS) at both postprocedure and 9 months was evaluated in 55 patients. The overlapped segment of R‐ZES was defined as the portion of R‐ZES superimposed on previous stent. Results Late loss and binary restenosis rate were 0.3 ± 0.5 mm and 5.5% at 9 months. On IVUS, the percentage of neointimal volume and maximum percentage of neointimal area were 3.9 ± 6.3% and 17.3 ± 15.5%, respectively. There was no significant change of vessel volume index between postprocedure and 9 months (16.9 ± 4.7 mm3/mm vs. 17.1 ± 4.6 mm3/mm, P = 0.251). Late‐acquired incomplete stent apposition was observed in 5 (5/55, 9.1%) cases. Compared with nonoverlapped segments of R‐ZES, the overlapped did not show larger neointimal volume index (0.3 ± 0.5 mm3/mm vs. 0.2 ± 0.3 mm3/mm, P = 0.187) on 9‐month IVUS. During follow‐up (median, 353 days), repeat target‐lesion revascularization was performed in four cases, but there were no death or stent thrombosis. Conclusions This study suggested that R‐ZES implantation for the treatment of ISR was effective up to 9 months and showed favorable vascular responses on serial IVUS assessment.