title: Effects of L-arginine supplementation on endothelial function after stent implantation.
abstract: BACKGROUND
  In-stent restenosis after percutaneous coronary intervention (PCI) is due to the proliferation of intima. Supplementation with L-arginine has been shown to improve endothelial function and decrease neointima proliferation in experimental animal model of restenosis.
  
  
  OBJECTIVE
  To assess the effects of L-arginine supplementation on neointima proliferation and endothelial markers as well as growth factor levels in patients after stent implantation.
  
  
  METHODS
  In this prospective, randomised, double-blind, placebo-controlled study 60 patients undergoing stent implantation received placebo or L-arginine (200 mg/kg infused intravenously over 4 hours, 12 and 3 hours before PCI, and 500 mg over 10 minutes prior to stent implantation, followed by oral supplementation of 6 g/day for 14 days after PCI). Quantitative coronary angiography (QCA) and intracoronary ultrasonography (ICUS) were performed at baseline and after a seven-month follow-up period. Serum concentration of L-arginine was measured at baseline, before PCI, 24 hours after PCI, and 7 as well as 14 days after PCI. The transforming growth factor-beta (TGF-beta), vascular endothelial growth factor (VEGF) and endothelin levels were assessed before PCI, and 24 hours as well as 14 days after the procedure.
  
  
  RESULTS
  No significant differences in the QCA or ICUS parameters were found between patients receiving L-arginine or placebo. 24 hours after stent implantation patients who received placebo had significantly a higher increase in the endothelin serum concentration and a lower rise in the VEGF level than the patients who received L-arginine (92.6+/-49 pg/ml vs 76.1+/-27 pg/ml, p<0.05, and 10 pg/ml vs 17.6+/-12 pg/ml, p<0.05, respectively). The TGF-beta level, assessed 14 days after PCI, was significantly higher in the placebo group than in the L-arginine group (14.8+/-10 ng/ml vs 11.2+/-6.1 ng/ml, p<0.05).
  
  
  CONCLUSIONS
  In spite of favourable changes in the vascular endothelial biochemical marker profile, supplementation with L-arginine did not decrease the in-stent reocclusion rate.
authors.affiliation: II Department of Cardiology, Institute of Cardiology, Jagiellonian University, Cracow, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dudek
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Heba
authors.forename: Stanisław
authors.initials: S
authors.lastname: Bartuś
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Partyka
authors.forename: Aldona
authors.initials: A
authors.lastname: Dembińska-Kieć
authors.forename: Jhor
authors.initials: J
authors.lastname: Huk
authors.forename: Jacek
authors.initials: J
authors.lastname: Legutko
authors.forename: Jacek S
authors.initials: JS
authors.lastname: Dubiel