1.
Adherence to guidelines strongly improves reproducibility of brachial artery flow-mediated dilation.
Greyling, A, van Mil, AC, Zock, PL, Green, DJ, Ghiadoni, L, Thijssen, DH, ,
Atherosclerosis. 2016;:196-202
Abstract
BACKGROUND Brachial artery FMD is widely used as a non-invasive measure of endothelial function. Adherence to expert guidelines is believed to be of vital importance to obtain reproducible measurements. We conducted a systematic review of studies reporting on the reproducibility of the FMD in order to determine the relation between adherence to current expert guidelines for FMD measurement and its reproducibility. METHODS Medline-database was searched through July 2015 and 458 records were screened for FMD reproducibility studies reporting the mean difference and variance of repeated FMD measurements. An adherence score was assigned to each of the included studies based on reported adherence to published guidelines on the assessment of brachial artery FMD. A Typical Error Estimate (TEE) of the FMD was calculated for each included study. The relation between the FMD TEE and the adherence score was investigated by means of Pearson correlation coefficients and multiple linear regression analysis. RESULTS Twenty-seven studies involving 48 study groups and 1537 subjects were included in the analyses. The adherence score ranged from 2.4 to 9.2 (out of a maximum of 10) and was strongly and inversely correlated with FMD TEE (adjusted R(2) = 0.36, P < 0.01). Use of automated edge-detection software, continuous diameter measurement, true peak diameter for %FMD calculation, a stereostatic probe holder, and higher age emerged as factors associated with a lower FMD TEE. CONCLUSIONS These data demonstrate that adherence to current expert consensus guidelines and applying contemporary techniques for measuring brachial artery FMD decreases its measurement error.
2.
Prostanoids are not involved in postocclusive reactive hyperaemia in human skin.
Hellmann, M, Gaillard-Bigot, F, Roustit, M, Cracowski, JL
Fundamental & clinical pharmacology. 2015;(5):510-6
Abstract
Several mediators contribute to postocclusive reactive hyperaemia (PORH) in the skin, including sensory nerves and endothelium-derived hyperpolarizing factors. The main objective of this study was to investigate the specific involvement of prostanoids in human skin PORH. We tested the effect of the inhibition of cyclo-oxygenases (COX) by 4 mm ketoprofen, infused through microdialysis fibers inserted into the healthy volunteers forearm skin, following 5 min brachial artery occlusion. Skin microvascular blood flux was recorded using two-dimensional Laser Speckle Contrast Imaging. Maximal cutaneous vascular conductance (CVCmax ) was obtained following the perfusion of 29 mm sodium nitroprusside. A systematic review of the effects of COX inhibitors on skin peak PORH was also performed. We observed no significant difference between ketoprofen and placebo for the PORH peak (78 ± 8 and 71 ± 19% CVCmax , respectively) and area under the curve (2951 ± 721 and 2490 ± 936% CVCmax .s). A meta-analysis showed a substantial heterogeneity between studies, with overall a neutral effect of COX inhibition on peak PORH. Cyclo-oxygenase inhibition does not alter skin PORH, suggesting no involvement of prostanoids in cutaneous postocclusive vasodilatation in healthy humans.
3.
Is there a role for measuring central aortic pressure?
Huan, Y, Townsend, R
Current cardiology reports. 2011;(6):502-6
Abstract
Peripheral brachial blood pressure measurements by sphygmomanometry remains the standard for measuring and managing blood pressure. Elevated brachial blood pressure is a major risk for cardiovascular disease, and reduction of bracial blood pressure decreases target organ damage and cardiovascular events. However, many patients still succumb to heart disease, stroke, kidney failure, and death even when the brachial blood pressures appear adequately controlled. Central aortic pressure may be more relevant to the pathogenesis of cardiovascular disease, which is not always accurately represented by brachial blood pressure. Noninvasive applanation tonometry can now assess central aortic pressure easily and reliably. Emerging data suggest that central arotic pressure and related parameters are often better and more robust predictors of cardiovascular outcome than peripheral brachial blood pressures.