October 17, 2007 - Compared to bare metal stents, in patients with acute myocardial infarction, sirolimus-eluting stent (SES) implantation aggravates endothelial vasomotor dysfunction in the infarct-related coronary artery, Japanese researchers report in the October 2nd issue of the Journal of the American College of Cardiology.
Kiyotaka Kugiyama, M.D., and colleagues at the University of Yamanashi, Chuo City note that drug-eluting stents reduce restenosis rates and revascularization but may impair recovery from reperfusion-induced endothelial injury.
To investigate, the researchers studied 29 patients with a first acute MI of the left anterior descending coronary artery (LAD). Thirteen had successful reperfusion therapy using an SES and the remaining 16 also had successful therapy employing a bare metal stent.
At two weeks, following intracoronary infusion of acetylcholine, the epicardial coronary artery became more severely restricted in the SES than the bare metal group. SES patients also had a lower increase in coronary blood flow in response to the agent.
In addition, levels of vascular endothelial growth factor (VEGF) in the anterior interventricular vein were significantly lower than in the aortic root in SES patients. This was not the case in the bare metal group.
The researchers stress that larger randomized studies are needed to confirm these findings. However, "these findings suggest that SES implantation may decrease the release of VEGF from the myocardial region supplied by the LAD, which may play a possible role in endothelial vasomotor dysfunction in infarct-related coronary arteries treated with SES."
Reference: J Am Coll Cardiol 2007;50:1305-1309