Effect Of Drug-eluting Stent On Coronary Endothelial Function

Objective:To explore coronary endothelial function in patients with drug-eluting stent implantation.Methods:From July 2006 to March 2007,66 patients with single stent implantation(33 in PES,33 in SES)were enrolled in this prospective study.Endothelium-dependent flow mediated dilation (FMD)and endothelium-independent nitroglycerin-mediated dilation (NMD)of brachial artery were assessed by high-resolution color Doppler ultrosound.FMD and NMD post-procedure and at 6-month follow-up after percutaneous coronary intervention(PCI) procedure were measured.Endothelium-dependent vasomotion and endothelium-independent vasomotion after intracoronary infusion of acetylcholine and nitroglycerin in a coronary segment 15 mm in length,starting 5mm distal to the stent,were assessed with quantitative coronary angiography(QCA)post-procedure and at 6-month follow-up after the procedure.Results:Clincal follow-up was available in 66 patients(100%). Angiographic and FMD/NMD follow-up was available in 55 patients(83.3%),nine patients,refused reangiography(4 PES patients, 5 SES patients),and two patients,showed in-stent restenosis at 6-month follow-up(1 in PES,1 in SES),were excluded from QCA analysis.There was significant difference in FMD between post-procedure versus at 6-month follow-up in either PES or SES group(8.7±2.9%vs 4.6±2.3%,P＜0.05;8.5±4.6%vs 6.8±3.4%,P＜0.05).Compared to SES group,PES group had lower value of FMD at 6-month follow-up(4.6±2.3%vs 6.8±3.4%,P＜0.05),whereas no marked differrence in NMD between groups(P＞0.05)was detected.There was significant difference in endotheliumdependent vasomotion(intracoronary infusion of acetylcholine)in the PES group between post-procedure versus at 6-month follow-up (-8±2%vs -32±3%,P＜0.05),similar to SES group(-4±2%vs -24±3%,P＜0.05).Compared to SES group,PES group had lower value of endothelium-dependent vasomotion at 6-month follow-up (-32±3%vs -24±3%,P＜0.05),without significant difference in endothelium-independent vasomotion(P＞0.05).Correlation analysis showed that FMD was positively correlated with endothelium-dependent vasomotion after intracoronary infusion of acetylcholine in both PES group(r=0.833,p＜0.01) and SES group(r=0.868,P＜0.01).Conclusion:Coronary endothelial function was impaired signifycantly after drug-eluting stent implantation,with more profound damage in the PES group.