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Drug Treatment of Hypertension: Focus on Vascular Health.
Cameron AC1, Lang NN1, Touyz RM2.
1Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, 126 University Place, Glasgow, G12 8TA, UK.
2Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, 126 University Place, Glasgow, G12 8TA, UK. email@example.com.
Hypertension, the most common preventable risk factor for cardiovascular disease and death, is a growing health burden. Serious cardiovascular complications result from target organ damage including cerebrovascular disease, heart failure, ischaemic heart disease and renal failure. While many systems contribute to blood pressure (BP) elevation, the vascular system is particularly important because vascular dysfunction is a cause and consequence of hypertension.
Hypertension is characterised by a vascular phenotype of endothelial dysfunction, arterial remodelling, vascular inflammation and increased stiffness. Antihypertensive drugs that influence vascular changes associated with high BP have greater efficacy for reducing cardiovascular risk than drugs that reduce BP, but have little or no effect on the adverse vascular phenotype. Angiotensin converting enzyme ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) improve endothelial function and prevent vascular remodelling. Calcium channel blockers also improve endothelial function, although to a lesser extent than ACEIs and ARBs. Mineralocorticoid receptor blockers improve endothelial function and reduce arterial stiffness, and have recently become more established as antihypertensive drugs. Lifestyle factors are essential in preventing the adverse vascular changes associated with high BP and reducing associated cardiovascular risk. Clinicians and scientists should incorporate these factors into treatment decisions for patients with high BP, as well as in the development of new antihypertensive drugs that promote vascular health.
Endothelial function and sympathetic nervous system activity in patients with Takotsubo syndrome.
Naegele M1, Flammer AJ2, Enseleit F2, Roas S1, Frank M1, Hirt A1, Kaiser P1, Cantatore S1, Templin C2, Fröhlich G1, Romanens M3, Lüscher TF4,Ruschitzka F4, Noll G4, Sudano I5.
Takotsubo syndrome (TTS) is an acute cardiomyopathy associated with intense physical or emotional stress. The precise mechanisms of the disease remain unclear. The aim of this study was to study alterations in endothelial function, vascular compliance and structure and muscle sympathetic activity in the stable phase of the disease.
In this prospective observational study, patients with TTS and controls matched for age, sex, cardiovascular risk factors and medications were recruited. Flow-mediated vasodilatation (FMD) as a measure of endothelial dysfunction was the primary endpoint. Secondary endpoints included measurements of arterial stiffness, carotid atherosclerosis, quality of life and laboratory parameters. In a subset of patients, muscle sympathetic activity was measured before and after stress tests.
The study included 22 TTS patients and 21 matched controls. A significant increase in endothelial dysfunction was seen in TTS compared to controls (FMD 3.4±2.4% vs. 4.8±1.9%, p=0.016). No significant differences in arterial stiffness, intima-media thickness, quality of life and laboratory markers including endothelin-1 were noted. TTS patients showed a reduced carotid total plaque area compared to controls (TPA 17.3±15.1 vs 24.7±12.8mm2, p=0.02). A trend of increased muscle sympathetic activity at rest was observed in TTS patients vs. controls (53.5±28.4 vs. 29.4±16.5 bursts/100 heart beats, p=0.09) with no significant differences in muscle sympathetic activity in response to stress.
Our findings underscore the importance of endothelial dysfunction in patients with TTS which may be involved in the pathophysiology of this syndrome.
J Hypertens. 2016 Sep 17. [Epub ahead of print]
Cholecalciferol treatment downregulates renin-angiotensin system and improves endothelial function in essential hypertensive patients with hypovitaminosid D.
Carrara D1, Bruno RM, Bacca A, Taddei S, Duranti E, Ghiadoni L, Bernini G.
Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
Vitamin D deficiency is related to an increased prevalence of cardiovascular disease. Renin-angiotensin-aldosterone system suppression and vascular dysfunction are considered among the main mechanisms implicated in this association. However, interventional studies demonstrating that vitamin D replacement reduces circulating renin-angiotensin-aldosterone components and improves vascular function in humans are still lacking.
Thirty-three consecutive patients with essential hypertension and hypovitaminosis D underwent therapy with cholecalciferol 50 000 IU/week orally for 8 weeks. Thirty-three hypertensive patients with normal vitamin D levels and 20 normotensive individuals were also enrolled as control groups. At baseline and at the end of the study, we evaluated plasma renin activity, circulating renin, angiotensin II, aldosterone and plasma vitamin D levels. Endothelial function [flow-mediated dilation (FMD)], carotid-femoral pulse wave velocity and augmentation index, peripheral and central blood pressure were also acquired.
After 8-week cholecalciferol administration, all treated patients normalized plasma 25(OH)D values. Furthermore, a reduction in plasma levels of plasma renin activity (1.17 ± 0.3 vs 1.51 ± 0.4 ng/ml per h, P = 0.02), renin (13.4 ± 1.7 vs 19.2 ± 2.9 pg/ml, P = 0.001), angiotensin II (11.6 ± 1.6 vs 15.8 ± 2.7 pg/ml, P = 0.02) was observed at the end of the study. FMD was significantly increased after cholecalciferol treatment (4.4 ± 2.6 vs 3.3 ± 2.1%, P = 0.05), in the absence of changes of brachial artery diameter and endothelium-independent vasodilation. Carotid-femoral pulse wave velocity and augmentation index were not modified, as well peripheral and central blood pressure.
The restoration of normal vitamin D levels after 8-week cholecalciferol treatment is able to inhibit peripheral renin-angiotensin system and improve FMD in essential hypertensive patients with hypovitaminosis D.
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