Treatment of Acute Myocardial Infarction With Sirolimus-Eluting Stents Results in Chronic Endothelial Dysfunction in the Infarct-Related Coronary Artery

BACKGROUND: Sirolimus-eluting stent (SES) implantation aggravated endothelial vasomotor dysfunction in infarct-related coronary arteries. METHODS AND RESULTS: This study examined the effect of SES implantation on the duration of reperfusion-induced endothelial vasomotor dysfunction in infarct-related coronary arteries and on postinfarct left ventricular dysfunction in acute myocardial infarction (AMI). Patients with a first AMI due to occlusion of the left anterior descending coronary artery and successful reperfusion using SES (n=15) or bare metal stents (BMS; n=18) were examined. The vasomotor response of the left anterior descending coronary artery to acetylcholine and left ventriculography were examined 2 weeks and 6 months after AMI. At 6 months after AMI, the impairment of epicardial coronary artery dilation and coronary blood flow increase in response to acetylcholine was recovered from 2 weeks after AMI in BMS-treated patients, whereas the responses of SES-treated patients improved but remained impaired compared with BMS-treated patients (% increase in blood flow, 77+/-12% in SES versus 116+/-15% in BMS at 10 microg/min of acetylcholine, P<0.01). Left ventricular regional wall dysfunction in the left anterior descending coronary artery territory improved from 2 weeks to 6 months after AMI in BMS-treated patients but not in SES-treated patients (% improvement of average SD/chord, 6% in SES versus 19% in BMS, P<0.05), although left ventricular global ejection fraction was similar between the groups at any time points. CONCLUSIONS: SES implantation may delay recovery of reperfusion-induced endothelial vasomotor dysfunction in infarct-related coronary arteries and left ventricular regional dysfunction for at least 6 months after AMI.