Abstract 2597: Differential Arterial Wave Reflection in ASCOT: an Explanation for the Results?
Background The Conduit Artery Functional Endpoint (CAFÉ) substudy of ASCOT showed that central blood pressure was significantly lower in those in the amlodipine-perindopril arm than those in the atenolol-bendrofluazide arm throughout the duration of the trial, despite similar brachial blood pressures. Arterial wave reflection contributes to the pathophysiology of hypertension, and different pharmacological agents may exert differing influences on this reflection and consequently on central blood pressure. Wave intensity analysis allows discrimination and direct measurement reflection waves . This tool was used to assess possible differences in wave reflection between the ASCOT treatment arms.
Method and Results We measured wave reflection using non-invasive wave intensity analysis in the carotid artery of 255 subjects (mean age 64±7.7 years) participating in ASCOT. The magnitude of wave reflection was significantly lower in the amlodipine-perindopril arm (n=120) than the atenolol-bendroflumethiazide arm (n=135), reflection coefficient 20% v 23% (p=0.02), (Figure 1⇓). There was no difference in the timing of wave reflection between the two treatment groups (p=0.86) when corrected for the length of systole.
Conclusions Wave reflection was reduced to a greater extent in ASCOT subjects in the amlodipine-perindopril arm than the atenolol-bendroflumethiazide arm. The greater wave reflection in the atenolol-bendroflumethiazide group may explain not only the higher central blood pressure seen in CAFÉ, but also the significantly higher endpoint rate in this limb of ASCOT.