Contradictory Effects of β1- and α1- Aderenergic Receptor Blockers on Cardio-Ankle Vascular Stiffness Index (CAVI)

Abstract

Aim:The cardio-ankle vascular stiffness index (CAVI) is a new parameter that reflects the stiffness of the aorta, femoral artery and tibial artery as a whole. One of its conspicuous features is that CAVI is independent of blood pressure at measuring time, theoretically. But, it has not been experimentally proved yet. For confirmation, pharmacological studies were performed comparing with brachial-ankle pulse wave velocity (baPWV). Methods: Used drugs were a 1-adrenoceptor blocker, metoprorol and an 1-adrenoceptor blocker doxazosin. Both were administered to 12 healthy volunteer men. CAVI and baPWV were measured every one hour for 6 hours using VaSera.

Analysis of vascular function using the cardio–ankle vascular index (CAVI)

“…Blood pressure will decrease as a result. In addition, brachial-ankle pulse wave velocity will thus decrease because pulse wave velocity depends on blood pressure at the time of the measurement, as reported by Nye et al [2][3][4]6 Under these conditions, a decrease in CAVI might be due to the relaxation of smooth muscle cells induced by general anesthesia itself and by administration of propofol. The report by Kim described two important features of CAVI: (1) CAVI expression changes over a short period of time, depending on the circulatory condition; and (2) CAVI expression reflects the state of smooth muscle cell contraction.…”

“…This lack of dependence was predicted by theory and was confirmed by several experimental studies. [2][3][4] The CAVI is high in aging patients and in patients with arteriosclerotic diseases, such as coronary artery disease, 7 carotid arteriosclerosis, 3,8 chronic kidney disease 9 , and is related to many coronary risk factors such as hypertension, 3 diabetes mellitus, 8 dyslipidemia 8 and smoking. 10 Furthermore, the CAVI decreases with control of diabetes mellitus and hypertension, as well as with abstention from smoking.…”

“…4 The paper demonstrated the effect of beta-and alpha-blockers on the CAVI in humans. In this study, a selective b1-receptor blocker, metoprolol, which is known to reduce the contraction of the heart muscle and decrease blood pressure without affecting the tone of the arterial wall, was administered to 12 men.…”

“…4 The CAVI decreased after the administration of doxazosin. These results support the hypothesis that the CAVI reflects vascular tone, representing both smooth muscle contraction and inorganic matrix components.…”

“…The CAVI was developed as a new index of the stiffness of the artery as a whole, from the origin of the aorta to the ankle. [2][3][4] The authors observed that both systolic and diastolic blood pressure decreased during generalized anesthesia using propofol. Simultaneously, brachial-ankle pulse wave velocity decreased along with the decrease in blood pressure.…”