Recent advances in managing primary hypertension

Hypertension remains a leading risk factor for cardiovascular mortality and morbidity globally despite the availability of effective and well-tolerated antihypertensive medications. Accumulating evidence suggests a more aggressive blood pressure regulation aimed at lower targets, particularly for selected patient groups. Our concepts of the optimal method for blood pressure measurement have radically changed, maintaining appropriate standard office measurements for initial assessment but relying on out-of-office measurement to better guide our decisions. Thorough risk stratification provides guidance in decision making; however, an individualized approach is highly recommended to prevent overtreatment. Undertreatment, on the other hand, remains a major concern and is mainly attributed to poor adherence and resistant or difficult-to-control forms of the disease. This review aims to present modern perspectives, novel treatment options, including innovative technological applications and developing interventional and pharmaceutical therapies, and the major concerns emerging from several years of research and epidemiological observations related to hypertension management.

Current evidence of sacubitril/valsartan in the treatment of heart failure with reduced ejection fraction

Heart failure (HF) is one of the most common reasons for hospital admission in western countries. The measurement of the left ventricular ejection fraction is essential for the classification of HF and deciding on HF treatment. The treatment of HF has been improved in both diagnostic and therapeutic fields over the past two decades. The angiotensin receptor-neprilysin inhibitor decreased the cardiovascular mortality in patients with chronic HF with reduced ejection fraction. Sacubitril/valsartan (LCZ696) improves the imbalance between the renin-angiotensin-aldosterone and natriuretic peptide systems. We present the clinical efficacy, real-world experience, safety and tolerability, the relevance of etiology of cardiomyopathy, and gender differences and regulatory affairs of LCZ696 in the treatment of patients with HF with reduced ejection fraction.

Drug therapy of apparent treatment-resistant hypertension: focus on mineralocorticoid receptor antagonists

Apparent treatment-resistant hypertension (aTRH) is defined as blood pressure (BP) >140/90 mmHg despite three different antihypertensive drugs including a diuretic. aTRH is associated with an increased risk of cardiovascular events, including stroke, chronic renal failure, myocardial infarction, congestive heart failure, aortic aneurysm, atrial fibrillation, and sudden death. Preliminary studies of renal nerve ablation as a therapy to control aTRH were encouraging. However, these results were not confirmed by the Symplicity 3 trial. Therefore, attention has refocused on drug therapy. Secondary forms of hypertension and associated conditions such as obesity, sleep apnea, and primary aldosteronism are common in patients with aTRH. The pivotal role of aldosterone in the pathogenesis of aTRH in many cases is well recognized. For patients with aTRH, the Joint National Committee-8, the European Society of Hypertension, and a recent consensus conference recommend that a diuretic, ACE inhibitor, or angiotensin receptor blocker and calcium channel blocker combination be used to maximally tolerated doses before starting a 'fourth-line' drug such as a mineralocorticoid receptor (MR) antagonist. Although the best fourth-line drug for aTRH has not been extensively investigated, a number of studies summarized here show that an MR antagonist is effective in reducing BP when added to the standard multi-drug regimen.

Comparison of aldosterone synthesis in adrenal cells, effect of various AT1 receptor blockers with or without atrial natriuretic peptide

Bifunctional angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) that can block the activation of not only AT1 receptor, but also neprilysin, which metabolizes vasoactive peptides including atrial natriuretic peptide (ANP), are currently being developed. However, the usefulness of the inactivation of ANP in addition to the AT1 receptor with regard to aldosterone (Ald) synthesis is not yet clear. We evaluated the inhibitory effects of various ARBs combined with or without ANP on Ang II-induced adrenal Ald synthesis using a human adrenocortical cell line (NCI-H295R). Ang II increased Ald synthesis in a dose- and time-dependent manner. Ald synthesis induced by Ang II was completely blocked by azilsartan, but not PD123319 (AT2 receptor antagonist). CGP42112 AT2 receptor agonist did not affect Ald synthesis. While most ARBs block Ang II-induced Ald synthesis to different extents, azilsartan and olmesartan have similar blocking effects on Ald synthesis. The different effects of ARBs were particularly observed at 10(-7) and 10(-8 )M. ANP attenuated Ang II-induced Ald synthesis, and ANP-mediated attenuation of Ang II-induced Ald synthesis were blocked by inhibitors of G-protein signaling subtype 4 and protein kinase G. ANP (10(-8) and 10(-7 )M) without ARBs inhibited Ald synthesis, and the combination of ANP (10(-7 )M) and ARB (10(-8 )M) had an additive effect with respect to the inhibition of Ald synthesis. In conclusions, ARBs had differential effects on Ang II-induced Ald synthesis, and ANP may help to block Ald synthesis when the dose of ARB is not sufficient to block its secretion.

Changes in levels of angiotensin II and its receptors in a model of inverted stress-induced cardiomyopathy

Background

Stress-induced cardiomyopathy (SIC) has gained increasing attention worldwide and is characterized by extensive ventricular akinesis, Beta-blockers and angiotensin-converting enzyme inhibitors (ACEIs) are the main treatments for SIC patients. The pharmacological mechanism of action of beta-blockers results in the inhibition of the biological effects of catecholamines. However, the mechanism of action of ACEIs in the treatment of cardiomyopathy is not known. Our aim is to assess changes in levels of angiotensin II, angiotensin-II receptors and ACE responses to SIC.

Methods

A model of inverted SIC was established in rabbits by vagal electrical stimulation. The serum concentration of angiotensin II and angiotensin (1-7) was detected by enzyme-linked immunosorbent assay. Expression of angiotensin-II receptors was measured by Western blotting and real-time reverse transcription-polymerase chain reaction (RT-PCR), with localization detected by immunofluorescent staining. ACE-II expression in the myocardium was measured by Western blotting.

Results

From one day after vagal stimulation, concentrations of angiotensin II were significantly higher in the experimental group than those in the control group (P <0.05). Stress induced a time-dependent decrease in angiotensin subtype-1 (AT1) expression and a time-dependent increase in AT2 expression only in the apical portion of the myocardium. From three days after vagal stimulation, angiotensin (1-7) levels were significantly lower in the experimental group compared with the control group (P <0.05). Expression of the ACE-II protein was significantly downregulated in the experimental group compared with the control group from three days after vagal stimulation (P <0.05).

Conclusions

Expression of angiotensin II, its receptors, ACE-II and angiotensin (1-7) was altered in response to SIC. The renin-angiotensin system could represent a therapeutic target in the prevention of SIC.

Electronic supplementary material

The online version of this article (doi:10.1186/s40001-014-0054-8) contains supplementary material, which is available to authorized users.