Antihypertensive treatment-induced changes in arterial stiffness: Which artery? Which method?

Automated pulse wave velocity assessment using a professional oscillometric office blood pressure monitor

Carotid-femoral pulse wave velocity (cfPWV) is the gold standard method for assessing arterial stiffness. This study evaluated automated brachial-ankle PWV (baPWV) taken by a professional oscillometric blood pressure monitor (Microlife WatchBP Office Vascular) versus reference cfPWV (Complior device). Subjects recruited from a hypertension outpatient clinic had duplicate baPWV and cfPWV measurements (randomized crossover design) and carotid ultrasonography. Of 102 subjects recruited, 101 had valid baPWV measurements. Four subjects were excluded and 97 were analyzed (age 58.3 ± 11.4 years, men 70%, hypertensives 76%, diabetics 17%, cardiovascular disease 10%, smokers 23%). The mean difference between baPWV (13.1 ± 1.8 m/s) and cfPWV (9.1 ± 1.8 m/s) was 4.0 ± 1.4 m/s (P < .01) with close association between them (r = 0.70, P < .01). baPWV and cfPWV were correlated with age (r 0.54/0.49 respectively), systolic blood pressure (0.45/0.50), carotid intima-media thickness (0.31/0.44), and carotid distensibility coefficient (-0.47/-0.34) (all P < .05; no difference between the two methods, z test). There was reasonable agreement (77%) between the two methods in identifying subjects at the top quartile of their distributions (kappa 0.39, P < .01). The areas under the receiver operating characteristic curves for the identification of carotid plaques were comparable for cfPWV and baPWV (0.79 and 0.74 respectively, P = NS). Automated baPWV measurement by a professional oscillometric blood pressure monitor is feasible and observer-independent. baPWV values differ from those by cfPWV, yet they are closely correlated, have reasonable agreement in detecting increased arterial stiffness and give similar associations with carotid stiffness and atherosclerosis.

Association between critical limb ischemia and arterial stiffness measured by brachial artery oscillometry

Background

Elevated arterial stiffness is associated with increased cardiovascular mortality. The relationship between arterial stiffness and critical limb ischemia (CLI) is not well established.

Objectives

The objective of this study is to analyze the relationship between arterial stiffness indices and the degree of limb ischemia measured by the ankle-brachial index (ABI).

Methods

A cross-sectional study comparing patients with CLI and controls. Arterial stiffness was measured using brachial artery oscillometry. The arterial stiffness indices pulse wave velocity (PWV) and augmentation index normalized to 75 beats/min (AIx@75) were determined. Multiple linear regression was applied to identify predictors of arterial stiffness indices.

Results

Patients in the CLI group had higher PWV (12.1±1.9 m/s vs. 10.1±1.9 m/s, p < 0.01) and AIx@75 (31.8±7.8% vs. 17.5±10.8%, p < 0.01) than controls. Central systolic pressure was higher in the CLI group (129.2±18.4 mmHg vs. 115.2±13.1 mmHg, p < 0.01). There was an inverse relationship between AIx@75 and ABI (Pearson coefficient = 0.24, p = 0.048), but there was no relationship between ABI and PWV (Pearson coefficient = 0.19, p = 0.12). In multiple regression analysis, reduced ABI was a predictor of elevated levels of AIx@75 (β = -25.02, p < 0.01).

Conclusions

Patients with CLI have high arterial stiffness measured by brachial artery oscillometry. The degree of limb ischemia, as measured by the ABI, is a predictor of increased AIx@75. The increased AIx@75 observed in CLI may have implications for the prognosis of this group of patients with advanced atherosclerosis.

Fibronectin type III domain containing 5 attenuates NLRP3 inflammasome activation and phenotypic transformation of adventitial fibroblasts in spontaneously hypertensive rats

OBJECTIVE

Phenotypic transformation of adventitial fibroblasts is important in the pathogenesis of hypertension. This study was designed to determine whether fibronectin type III domain containing 5 (FNDC5) alleviates the phenotypic transformation of adventitial fibroblasts in hypertension and the underlying mechanisms.

METHODS AND RESULTS

Experiments were carried out in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) and primary aortic adventitial fibroblasts. FNDC5 was downregulated and NLRP3 inflammasome was activated in aortic adventitia of SHR. FNDC5 overexpression attenuated adventitial fibroblasts phenotypic transformation, excessive synthesis and secretion of matrix components, NLRP3 inflammasome activation and inflammation in adventitial fibroblasts from SHR. Moreover, FNDC5 overexpression reduced NADPH oxidase 2 (NOX2) expression and reactive oxygen species (ROS) production in adventitial fibroblasts from SHR. Similarly, exogenous FNDC5 inhibited adventitial fibroblasts phenotypic transformation, expression of matrix components, NLRP3 inflammasome activation and NOX2 expression in adventitial fibroblasts from SHR. FNDC5 overexpression in rats attenuated phenotypic transformation, inflammation and reactive oxygen species (ROS) production in the aortic adventitia of SHR. Furthermore, FNDC5 overexpression reduced blood pressure and alleviated vascular remodeling in SHR.

CONCLUSION

FNDC5 reduces NOX2-derived ROS production, NLRP3 inflammasome activation and phenotypic transformation in adventitial fibroblasts of SHR. FNDC5 plays a beneficial role in attenuating vascular inflammation, vascular remodeling and hypertension in SHR.