title: Anti-Vascular endothelial growth factor therapy impairs endothelial function of retinal microcirculation in colon cancer patients - an observational study.
abstract: BACKGROUND
  To assess acute effects of bevacizumab (anti-VEGF therapy) on cerebral microvessels and systemic cardiovascular regulation.
  
  
  METHODS
  20 consecutive patients with colorectal cancer (median age: 60.4 years, range 45.5-73.9 years) received bevacizumab intravenously (5 mg/kg) uncoupled of chemotherapy. Prior to and within the first 24 hours after bevacizumab infusion, patients were investigated for retinal endothelial function. A series of a triple 24-hour ambulatory blood pressure measurement was conducted. Retinal endothelial function was determined as flicker light-induced vasodilation. The integrity of baroreflex arc and autonomic cardiovascular control was examined by stimulatory manoeuvres.
  
  
  RESULTS
  Bevacizumab therapy significantly reduced the vasodilatory capacity of retinal arterioles in response to flicker light. A slight decrease in diastolic pressure and heart rate was observed after bevacizumab infusion but this was unrelated to changes in retinal function. The pressure response upon nitroglycerin was largely preserved after bevacizumab infusion. The proportion of patients with abnormal nocturnal blood pressure regulation increased under anti-angiogenic therapy. Autonomic blood pressure control was not affected by bevacizumab treatment.
  
  
  CONCLUSIONS
  Bevacizumab acutely impairs microvascular function independent of blood pressure changes. Imaging of the retinal microcirculation seems a valuable tool for monitoring pharmacodynamic effects of bevacizumab.
  
  
  BACKGROUND
  NCT ID: NCT00740168.
authors.affiliation: Autonomic and neuroendocrinological laboratory, Center of Clinical Neuroscience, University Hospital Carl Gustav Carus, Dresden, Fetscherstr 74, Germany.|Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Manja
authors.initials: M
authors.lastname: Reimann
authors.affiliation: Department of Internal Medicine I, University Cancer Center, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Folprecht
authors.affiliation: Autonomic and neuroendocrinological laboratory, Center of Clinical Neuroscience, University Hospital Carl Gustav Carus, Dresden, Fetscherstr 74, Germany.|Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Rocco
authors.initials: R
authors.lastname: Haase
authors.affiliation: Department of Internal Medicine I, University Cancer Center, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Karolin
authors.initials: K
authors.lastname: Trautmann
authors.affiliation: Department of Internal Medicine I, University Cancer Center, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ehninger
authors.affiliation: Autonomic and neuroendocrinological laboratory, Center of Clinical Neuroscience, University Hospital Carl Gustav Carus, Dresden, Fetscherstr 74, Germany.|Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Reichmann
authors.affiliation: Center for Ophthalmology, Eberhard Karl University Tuebingen, Tuebingen, Germany.
authors.forename: Focke
authors.initials: F
authors.lastname: Ziemssen
authors.affiliation: Autonomic and neuroendocrinological laboratory, Center of Clinical Neuroscience, University Hospital Carl Gustav Carus, Dresden, Fetscherstr 74, Germany.|Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Tjalf
authors.initials: T
authors.lastname: Ziemssen