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.