title: The effect of different β-blockers on vascular graft nitric oxide levels: comparison of nebivolol versus metoprolol.
abstract: OBJECTIVE
  The aim of this study was to investigate the effects of the vasodilating β-blocker nebivolol and the cardioselective β-blocker metoprolol on nitric oxide (NO) levels at vascular graft endothelium and vasa vasorum compared to controls in patients undergoing coronary artery bypass graft surgery.
  
  
  METHODS
  This was a prospective study. Fifty-five patients were divided into three groups: nebivolol group (group N, n = 23), metoprolol group (group M, n = 16), and control group (group A, n = 16). Group N received nebivolol 5 mg once daily, and group M received metoprolol 50 mg once daily for 15 days in the preoperative period. Control patients did not use β-blocker therapy. Tissue samples of both left internal mammary artery (LIMA) and saphenous vein grafts were investigated for NO activity using immunohistochemical methods.
  
  
  RESULTS
  Demographic characteristics and risk factors were similar between groups. We observed the highest NO activity in group N in both endothelial and vasa vasorum samples of LIMA and saphenous veins. NO activity of metoprolol group was similar to controls.
  
  
  CONCLUSIONS
  According to our results, we think that nebivolol may be safer and preferable in order to diminish graft spasm in patients undergoing coronary artery bypass graft surgery due to the NO-mediated vasodilating effect.
authors.affiliation: Gaziantep University, Faculty of Medicine, Department of Cardiovascular Surgery, Gaziantep, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Bayar
authors.affiliation: Recep Tayyip Erdogan University, Faculty of Medicine, Department of Cardiovascular Surgery, Rize, Turkey. Electronic address: drgknilhan@yahoo.com.
authors.forename: G
authors.initials: G
authors.lastname: Ilhan
authors.affiliation: Recep Tayyip Erdogan University, Faculty of Medicine, Department of Cardiovascular Surgery, Rize, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Furat
authors.affiliation: Gaziantep University, Faculty of Medicine, Department of Cardiovascular Surgery, Gaziantep, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Atik
authors.affiliation: Gaziantep University, Faculty of Medicine, Department of Cardiovascular Surgery, Gaziantep, Turkey.
authors.forename: Y
authors.initials: Y
authors.lastname: Arslanoglu
authors.affiliation: Gaziantep University, Faculty of Medicine, Department of Cardiovascular Surgery, Gaziantep, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Kuran
authors.affiliation: Izmir Katip Celebi University, Ataturk Education and Research Hospital, Department of Cardiovascular Surgery, Izmir, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Ozpak
authors.affiliation: Recep Tayyip Erdogan University, Faculty of Medicine, Department of Cardiology, Rize, Turkey.
authors.forename: M E
authors.initials: ME
authors.lastname: Durakoglugil
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000368:Aged; D001578:Benzopyrans / Q000008:administration & dosage*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass / Q000009:adverse effects; D004334:Drug Administration Schedule; D004983:Ethanolamines / Q000008:administration & dosage*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects* / Q000378:metabolism / Q000601:surgery; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D000068577:Nebivolol; D009569:Nitric Oxide / Q000378:metabolism*; D011446:Prospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000187:drug effects* / Q000378:metabolism / Q000637:transplantation; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey; D014661:Vasoconstriction / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D000319:Adrenergic beta-Antagonists; D001578:Benzopyrans; D004983:Ethanolamines; D014665:Vasodilator Agents; D000068577:Nebivolol; D009569:Nitric Oxide; D008790:Metoprolol
keywords: Beta blocker; Coronary artery bypass graft surgery; Metoprolol; Nebivolol; Nitric oxide