Abstract 2158: Long-lasting Impairment of Endothelial Vasomotor Function in Infarct-related Coronary Artery Treated with Sirolimus-eluting Stent in Patients with Acute Myocardial Infarction
Sirolimus-eluting stent (SES) causes endothelial dysfunction in downstream coronary arteries distal to the stent site. Thus, it is possible that SES implantation can potentially aggravate endothelium-dependent vasomotor dysfunction in infarct-related coronary arteries. This study examined the effect of SES implantation on duration of reperfusion-induced endothelial dysfunction in infarct-related coronary arteries and on post-infarct left ventricular (LV) dysfunction.
Methods and Results: This study enrolled 24 patients with a first acute myocardial infarction (AMI) due to occlusion of the left anterior descending coronary artery (LAD) and successful reperfusion therapy using SESs (n = 12) or bare metal stents (BMS, n = 12). All patients underwent left ventriculography and LAD vasomotor function testing in response to acetylcholine (ACh) that were repeated 2 weeks and 6 months after AMI. Patients with either residual stenosis or in-stent restenosis in LAD were not included in this study. The SES and BMS groups were similar in terms of AMI-related variables including peak CK levels, 2-week LV ejection fraction (LVEF), and 2-week regional wall motion (RWM) of the affected LV, assessed by the centerline method and expressed in units of standard deviations (SD) of the normal mean. At 2 weeks after AMI, LAD of patients with SES had greater impairment of epicardial dilation and less blood flow increase in response to ACh than those with BMS. At 6 months, the responses of epicardial diameter and blood flow to ACh in BMS-treated LAD had recovered to levels similar to those of healthy subjects, while responses of SES-treated LAD remained impaired compared with BMS-treated LAD (% increase in blood flow from baseline; 76 ± 8% in SES vs. 138 ± 9% in BMS at 10 μg/min of ACh, p < 0.01). Vasomotor responses to nitrates and sodium nitroprusside were comparable between the 2 groups. Patients with SES had less RWM at 6 months and a lower % improvement of global LVEF from 2 weeks to 6 months than patients with BMS (RWM; −2.7 vs. −2.4 SD/chord, ΔLVEF; 5.0% vs. 8.4%, respectively, both p < 0.01).
Conclusions: SES adversely affects endothelium-dependent vasomotor function in infarct-related coronary arteries and post-MI LV function until at least 6 months after stent implantation.