Clinical usefulness of augumantation index at radial artery as a predictive factor of cardiovascular events in patients with hypertension

Augmentation index (AIx) is known to be a good surrogate marker of systemic arterial stiffness. Recently, AIx can be measured at radial artery using the OMRON device. The purpose of this study is to clarify the clinical usefulness of AIx at radial artery as a predictive factor of cardiovascular events in patients with hypertension. 220 hypertensive patients (131males, mean age 64.3± 9.3years) were enrolled. We measured AIx at left radial artery and evaluated relation with coronary and carotid atherosclerosis. AIx was defined as the ratio of the height of the late systolic shoulder peak to that of the early sysrolic shoulder peak in the pulse. There were significantly correlation between age, height, heart rate and AIx (r=0.19, -0.25, -0.13 p=0.003, 0.0002, 0.04 respectively), however, blood pressure levels had no correlation with AIx. Patients with coronary atherosclerosis (angiographycally significant stenosis and/or history of myocardial infarction) and abnormality of carotid ultrasound (intima-media thickness ≥1.1mm and/or presence of plaque) had significantly high AIx levels than the patients without these factors (94.9±10.9 vs 87.6±12.6%, 95.3±12.7 vs 86.1±10.9%, p<0.0001, p<0.0001 respectively), furthermore, multiple regression analysis showed that presence of coronary atherosclerosis and abnormality of carotid ultrasound were independent variables for AIx among the factors which influenced AIx (p<0.0001, ph0.0001 respectively). These results indicate that possibility of AIx at radial artery using OMRON device as a predictive factor of cardiovascular events in patients with hypertension.