Different vascular response to concurrent implantation of sirolimus- and zotarolimus-eluting stents in the same vessel.

Drug-eluting stents (DES) have become routine therapy in clinical practice because restenosis is significantly reduced in patients treated with these devices. New generations of DES bearing newer antiproliferative drugs have been developed. Sirolimus was the first antiproliferative drug eluted by a DES (SES) while zotarolimus represents a sirolimus-derived, newer antiproliferative drug borne by a different kind of DES (ZES). This report describes two cases of different vascular response to concurrent side by side implantation of SES and ZES in the same vessel and highlights significant early restenosis of ZES as compared with SES.