title: Validity of pulse pressure and augmentation index as surrogate measures of arterial stiffness during beta-adrenergic stimulation.
abstract: OBJECTIVE
  Increased arterial stiffness is a determinant of cardiovascular mortality. Pulse wave velocity (PWV) is a direct measure of arterial stiffness. Aortic augmentation index (AI) and pulse pressure (PP) are surrogate measures of arterial stiffness. Both PWV, AI and PP increase with cardiovascular risk factors. The aim of this study was to test the validity of AI and PP as surrogate measures of arterial stiffness compared with PWV, during beta-adrenergic stimulation with Isoprenaline (Iso).
  
  
  METHODS
  A total of 41 healthy volunteers entered a randomized, double-blind, placebo-controlled, cross-over study. In random order, subjects were given intravenous infusion in equal volume of Iso 8 microg/kg per min (dissolved in glucose 5%) and placebo (glucose 5%). A wash-out period of 25 min was observed between the infusions. Measurements included blood pressure (BP), heart rate (HR), PWV, and AI. PWV were determined using complior (Complior, Artech-Medical, Paris, France). AI and aortic PP were obtained from pulse wave analysis of radial applanation tonometry, using transfer function (SphygmoCor Windows software).
  
  
  RESULTS
  Baseline AI increased (P < 0.05) with aging, a lower height and a larger diastolic BP (DBP). Iso increased (P < 0.0001) HR, brachial SBP, brachial and aortic PP as compared with placebo. In contrast, Iso decreased (P < 0.05) AI, brachial DBP, peripheral PWV, but not aortic PWV. Decrease of AI induced by Iso was not related to PWV. In stepwise multiple regression changes in HR, brachial SBP and DBP were independent determinants of AI response to Iso (r = 0.78, P < 0.0001).
  
  
  CONCLUSIONS
  Our findings show that AI and PP fail as surrogate measures of arterial stiffness during beta-adrenergic stimulation.
authors.affiliation: Department of Cardiology, Erasme Hospital, Brussels, Belgium. pvandebo@ulb.ac.be
authors.forename: Daniel
authors.initials: D
authors.lastname: Lemogoum
authors.forename: Gabriella
authors.initials: G
authors.lastname: Flores
authors.forename: Wouter
authors.initials: W
authors.lastname: Van den Abeele
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ciarka
authors.forename: Marc
authors.initials: M
authors.lastname: Leeman
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Degaute
authors.forename: Philippe
authors.initials: P
authors.lastname: van de Borne
authors.forename: Luc
authors.initials: L
authors.lastname: Van Bortel
mesh_terms: D000318:Adrenergic beta-Agonists; D000328:Adult; D000367:Age Factors; D001011:Aorta / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects*; D001827:Body Height; D001916:Brachial Artery / Q000503:physiopathology; D018592:Cross-Over Studies; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D007545:Isoproterenol; D008297:Male; D011673:Pulsatile Flow / Q000187:drug effects; D013318:Stroke Volume
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol