Jin Won Kim, MD, PhD, Hong Seog Seo, MD, PhD, Jae Hyoung Park, MD, Jin Oh Na, MD, Cheol Ung Choi, MD, Hong Euy Lim, MD, PhD, Eung Ju Kim, MD, PhD, Seung-Woon Rha, MD, PhD, Chang Gyu Park, MD, PhD and Dong Joo Oh, MD, PhD*

Cardiovascular Center, Korea University, Guro Hospital, Seoul, Korea

Manuscript received August 14, 2008; revised manuscript received January 12, 2009, accepted January 12, 2009.

*Reprint requests and correspondence: Dr. Dong Joo Oh, Guro Hospital Cardiovascular Center, Korea University, 97 Gurodong-Gil Guro-gu, Seoul, Republic of Korea, 152-703.

Objectives: We prospectively compared coronary endothelial dysfunction in patients with zotarolimus-eluting stent (ZES) versus sirolimus-eluting stent (SES) implantation at 6-month follow-up.

Background: A ZES has been associated with uniform and rapid healing of the endothelium.

Methods: Fifty patients were randomly treated with intravascular ultrasound-guided stenting with a single stent to the mid-segment of the left anterior descending artery (20 ZES, 20 SES, and 10 bare-metal stents), and endothelial function was estimated before and after intervention at 6-month follow-up by incremental acetylcholine (Ach) (10, 20, 50, and 100 µg/min) and nitrate (200 µg/min) infusions into the left coronary ostium. The vascular response was quantitatively measured in the 5-mm segments proximal and distal to the stent.

Results: In the drug-eluting stent groups, more intense vasoconstriction to incremental doses of Ach was observed at 6-month follow-up compared with the responses before stenting. Endothelial function associated with the ZES was more preserved at 6-month follow-up compared with the SES. Vasoconstriction to Ach was more prominent in the distal segments than the proximal segments in both the ZES and SES groups. Endothelium-independent vasodilation to nitrate did not differ significantly among the study groups.

Conclusions: Vasoconstriction in response to Ach in the peri-stent region was less pronounced in the ZES group than the SES group at 6-month follow-up, which suggests that endothelial function associated with ZES can be more preserved than the SES.

Key Words: acetylcholine, BMS, DES, endothelial dysfunction, SES, ZES