Validity of pulse pressure and augmentation index as surrogate measures of arterial stiffness during beta-adrenergic stimulation.
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.
Lemogoum
Daniel
D
Department of Cardiology, Erasme Hospital, Brussels, Belgium. pvandebo@ulb.ac.be
Flores
Gabriella
G
Van den Abeele
Wouter
W
Ciarka
Agnieszka
A
Leeman
Marc
M
Degaute
Jean Paul
JP
van de Borne
Philippe
P
Van Bortel
Luc
L
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
D000318:Adrenergic beta-Agonists; D007545:Isoproterenol