title: Oxidative stress and nitric oxide pathway in adult patients who are candidates for cardiac surgery: patterns and differences.
abstract: OBJECTIVE
  We investigated whether oxidative stress and the arginine/nitric oxide pathway differ in control subjects and in adult patients who are candidates for the three most common cardiac surgical operations: coronary bypass surgery, aortic valve replacement for calcific non-rheumatic aortic stenosis or mitral valve repair for degenerative mitral insufficiency.
  
  
  METHODS
  In this prospective observational study, we studied 165 consecutive patients undergoing surgery from January to June 2011 (coronary bypass surgery, n = 63; aortic valve replacement for calcific non-rheumatic aortic stenosis, n = 51; mitral valve repair for degenerative mitral insufficiency, n = 51). Thirty-three healthy subjects with cardiovascular risk factors similar to surgery patients were also studied (Controls). Oxidative stress (the ratio of reduced and oxidized glutathione and urinary isoprostane), antioxidants (alpha- and gamma tocopherol) and factors involved in nitric oxide synthesis (arginine, symmetric and asymmetric dimethylarginine) were measured before surgery. Analysis of variance general linear models and principal component analysis were used for statistical analysis.
  
  
  RESULTS
  Surgical patients had increased levels of oxidative stress and decreased levels of antioxidants. Increased levels of nitric oxide inhibitor asymmetric dimethylarginine were detected in surgical candidates, suggesting arginine/nitric oxide pathway impairment. Concerning the differences among surgical procedures, higher oxidative stress and a major imbalance of the ratio between substrate and inhibitors of nitric oxide synthesis were evidenced in patients who were candidates for mitral valve repair with respect to coronary bypass surgery patients and patients with calcific non-rheumatic aortic stenosis.
  
  
  CONCLUSIONS
  Patients undergoing cardiac surgery have increased oxidative stress and a trend towards an impaired arginine/nitric oxide pathway with respect to Controls. Patients affected by mitral valve regurgitation show more pronounced perturbations in these pathways. The clinical implications of these findings need to be investigated.
authors.affiliation: Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Cavalca
authors.forename: Elena
authors.initials: E
authors.lastname: Tremoli
authors.forename: Benedetta
authors.initials: B
authors.lastname: Porro
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Veglia
authors.forename: Veronika
authors.initials: V
authors.lastname: Myasoedova
authors.forename: Isabella
authors.initials: I
authors.lastname: Squellerio
authors.forename: Daniela
authors.initials: D
authors.lastname: Manzone
authors.forename: Marco
authors.initials: M
authors.lastname: Zanobini
authors.forename: Matteo
authors.initials: M
authors.lastname: Trezzi
authors.forename: Matteo Nicola Dario
authors.initials: MN
authors.lastname: Di Minno
authors.forename: José Pablo
authors.initials: JP
authors.lastname: Werba
authors.forename: Calogero
authors.initials: C
authors.lastname: Tedesco
authors.forename: Francesco
authors.initials: F
authors.lastname: Alamanni
authors.forename: Alessandro
authors.initials: A
authors.lastname: Parolari
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D001021:Aortic Valve / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002114:Calcinosis / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress; D025341:Principal Component Analysis; D011446:Prospective Studies
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D009569:Nitric Oxide
keywords: Aortic valve stenosis; Coronary artery disease; Mitral valve regurgitation; Nitric oxide; Oxidative stress