The vasodilatory beta-blockers

The effects of antihypertensive drugs on glucose metabolism

Abnormal glucose metabolism is a common disease of the endocrine system. The effects of drugs on glucose metabolism have been reported frequently in recent years, and since abnormal glucose metabolism increases the risk of microvascular and macrovascular complications, metabolic disorders, and infection, clinicians need to pay close attention to these effects. A variety of common drugs can affect glucose metabolism and have different mechanisms of action. Hypertension is a common chronic cardiovascular disease that requires long-term medication. Studies have shown that various antihypertensive drugs also have an impact on glucose metabolism. Among them, α-receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers can improve insulin resistance, while β-receptor blockers, thiazides and loop diuretics can impair glucose metabolism. The aim of this review was to discuss the mechanisms underlying the effects of various antihypertensive drugs on glucose metabolism in order to provide reference information for rational clinical drug use.

Beta-Blockers and Hypertension: Some Questions and Answers

INTRODUCTION

International guidelines have removed b-blockers from first-line treatment of hypertension, limiting their use to patients with compelling indications. The position of guidelines stems from the results of studies performed with the 1st and 2nd generation of b-blockers, which concluded that these drugs have lower cardiovascular protection, compared with other antihypertensive agents.

AIM

The aim of our mini review is to answer to some questions about the effect of b-blockers on hypertension and cardiovascular protection and if these effects are different from those of other antihypertensive drugs, particularly in young and elderly patients.

METHODS

We evaluated the relevant systematic reviews and meta-analyses, which reported the effectiveness of b-blockers on blood pressure and cardiovascular outcomes, compared with placebo/no treatment and with other antihypertensive agents.

RESULTS

Beta-blockers, decreased high blood pressure with no significant difference from other common antihypertensive agents. Moreover b-blockers, compared with placebo, lowered the risk of major cardiovascular outcomes, while, compared with other drug classes, the reported results are very heterogeneous. Therefore it is difficult, globally, to find a difference between b-blockers and other drug classes.

CONCLUSIONS

Rather than looking for differences in the cardiovascular protective effect between b-blockers and other antihypertensive agents, we have to consider the different pathophysiology of hypertension in young [sympathetic hyperactivity] and elderly patients [arterial stiffness, high aortic systolic pressure]. Considering these aspects, non-vasodilating b-blockers are preferred, as first-line, in young/middle aged hypertensive subjects, while vasodilating b-blockers, are most appropriate, in elderly patients, for the favourable hemodynamic profile.

Nebivolol: an effective option against long-lasting dyspnoea following COVID-19 pneumonia - a pivotal double-blind, cross-over controlled study

Background

Pulmonary microvascular occlusions can aggravate SARS-CoV-2 pneumonia and result in a variable decrease in capillary blood volume (Vc). Dyspnoea may persist for several weeks after hospital discharge in many patients who have "radiologically recovered" from COVID-19 pneumonia. Dyspnoea is frequently "unexplained" in these cases because abnormalities in lung vasculature are understudied. Furthermore, even when they are identified, therapeutic options are still lacking in clinical practice, with nitric oxide (NO) supplementation being used only for severe respiratory failure in the hospital setting. Nebivolol is the only selective β¹ adrenoceptor antagonist capable of inducing nitric oxide-mediated vasodilation by stimulating endothelial NO synthase via β₃ agonism. The purpose of this study was to compare the effect of nebivolol versus placebo in patients who had low Vc and complained of dyspnoea for several weeks after COVID-19 pneumonia.

Methods

Patients of both genders, aged ≥18 years, non-smokers, who had a CT scan that revealed no COVID-related parenchymal lesions but still complaining of dyspnoea 12-16 weeks after hospital discharge, were recruited. Spirometrical volumes, blood haemoglobin, SpO₂, simultaneous diffusing capacity for carbon monoxide (CO) and NO (DL_CO and DL_NO, respectively), DL_NO/DL_CO ratio, Vc and exhaled NO (eNO) were measured together with their dyspnoea score (DS), heart frequency (HF), and blood arterial pressure (BAP). Data were collected before and one week after both placebo (P) and nebivolol (N) (2.5 mg od) double-blind cross-over administered at a two-week interval. Data were statistically compared, and p<0.05 assumed as statistically significant.

Results

Eight patients (3 males) were investigated. In baseline, their mean DS was 2.5±0.6 SD, despite the normality of lung volumes. DL_CO and DL_NO mean values were lower than predicted, while mean DL_NO/DL_CO ratio was higher. Mean Vc proved substantially reduced. Placebo did not modify any variable (all p=ns) while N improved DLco and Vc significantly (+8.5%, p<0.04 and +17.7%, p<0.003, respectively). eNO also was significantly increased (+17.6%, p<0.002). Only N lowered the dyspnoea score (-76%, p<0.001). Systolic and diastolic BAP were slightly lowered (-7.5%, p<0.02 and -5.1%, p<0.04, respectively), together with HF (-16.8%, p<0.03).

Conclusions

The simultaneous assessment of DL_NO, DL_CO, DL_NO/DL_CO ratio, and Vc confirmed that long-lasting dyspnoea is related to hidden abnormalities in the lung capillary vasculature. These abnormalities can persist even after the complete resolution of parenchymal lesions regardless of the normality of lung volumes. Nebivolol, but not placebo, improves DS and Vc significantly. The mechanism suggested is the NO-mediated vasodilation via the β3 adrenoceptor stimulation of endothelial NO synthase. This hypothesis is supported by the substantial increase of eNO only assessed after nebivolol. As the nebivolol tolerability in these post-COVID normotensive patients was very good, the therapeutic use of nebivolol against residual and symptomatic signs of long-COVID can be suggested in out-patients.

Effects of epidural anesthesia in pheochromocytoma and paraganglioma surgeries: A protocol for systematic review and meta-analysis

OBJECTIVE

Anesthetic management is a great challenge during the surgical resection of pheochromocytomas and paragangliomas (PPGLs) due to potential hemodynamic fluctuations and/or postoperative complications. Although combined epidural-general anesthesia is commonly used in PPGLs surgeries, there is still no consensus whether combined epidural-general anesthesia was superior than general anesthesia alone for these populations. For the first time, we conducted this systematic review and meta-analysis to summarize the effects of combined epidural-general anesthesia versus general anesthesia alone on hemodynamic fluctuations as well as postoperative complications in patients undergone PPGLs surgeries.

METHODS

This systematic review and meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses statement. The primary outcome were hemodynamic fluctuations, including intraoperative hypotension, postoperative hypotension, and hypertensive crisis. Secondary outcome was the incidence of postoperative complications during hospital stay.

RESULTS

Finally, three retrospective cohort studies involving 347 patients met the inclusion criteria. A meta-analysis was not performed since outcomes from included studies were not available to be pooled. On the basis of the findings of non-randomized controlled trials (RCTs) literature, 2 studies suggested that combined epidural-general anesthesia was associated with intraoperative and postoperative hypotension, although one study reported that epidural anesthesia use reduced the incidence of postoperative complications in patients undergone surgical resection of PPGLs.

CONCLUSIONS

Currently, no published RCTs have yet assessed clinically relevant outcomes with respect to the application of epidural anesthesia during PPGLs surgeries. Well-designed RCTs should nonetheless be encouraged to properly assess the efficacy and safety of epidural anesthesia for PPGLs surgeries.

Beta-adrenergic receptor blockade in angiosarcoma: Which beta-blocker to choose?

Beta-blockers are currently studied to improve therapeutic options for patients with angiosarcoma. However, most of these patients have no cardiovascular co-morbidity and it is therefore crucial to discuss the most optimal pharmacological properties of beta-blockers for this population. To maximize the possible effectiveness in angiosarcoma, the use of a non-selective beta-blocker is preferred based on in vitro data. To minimize the risk of cardiovascular adverse events a beta-blocker should ideally have intrinsic sympathomimetic activity or vasodilator effects, e.g. labetalol, pindolol or carvedilol. However, except for one case of carvedilol, only efficacy data of propranolol is available. In potential follow-up studies labetalol, pindolol or carvedilol can be considered to reduce the risk of cardiovascular adverse events.

Mechanisms and Clinical Implications of Endothelial Dysfunction in Arterial Hypertension

The endothelium is composed of a monolayer of endothelial cells, lining the interior surface of blood and lymphatic vessels. Endothelial cells display important homeostatic functions, since they are able to respond to humoral and hemodynamic stimuli. Thus, endothelial dysfunction has been proposed as a key and early pathogenic mechanism in many clinical conditions. Given the relevant repercussions on cardiovascular risk, the complex interplay between endothelial dysfunction and systemic arterial hypertension has been a matter of study in recent years. Numerous articles have been published on this issue, all of which contribute to providing an interesting insight into the molecular mechanisms of endothelial dysfunction in arterial hypertension and its role as a biomarker of inflammation, oxidative stress, and vascular disease. The prognostic and therapeutic implications of endothelial dysfunction have also been analyzed in this clinical setting, with interesting new findings and potential applications in clinical practice and future research. The aim of this review is to summarize the pathophysiology of the relationship between endothelial dysfunction and systemic arterial hypertension, with a focus on the personalized pharmacological and rehabilitation strategies targeting endothelial dysfunction while treating hypertension and cardiovascular comorbidities.

Pharmacological differences between beta-blockers and postoperative mortality following colon cancer surgery

β-blocker therapy has been positively associated with improved survival in patients undergoing oncologic colorectal resection. This study investigates if the type of β-blocker used affects 90-day postoperative mortality following colon cancer surgery. The study was designed as a nationwide retrospective cohort study including all adult (≥ 18 years old) patients with ongoing β-blocker therapy who underwent elective and emergency colon cancer surgery in Sweden between January 1, 2007 and December 31, 2017. Patients were divided into four cohorts: metoprolol, atenolol, bisoprolol, and other beta-blockers. The primary outcome of interest was 90-day postoperative mortality. A Poisson regression model with robust standard errors was used, while adjusting for all clinically relevant variables, to determine the association between different β-blockers and 90-day postoperative mortality. A total of 9254 patients were included in the study. There was no clinically significant difference in crude 90-day postoperative mortality rate [n (%)] when comparing the four beta-blocker cohorts metoprolol, atenolol, bisoprolol and other beta-blockers. [97 (1.8%) vs. 28 (2.0%) vs. 29 (1.7%) vs. 11 (1.2%), p = 0.670]. This remained unchanged when adjusting for relevant covariates in the Poisson regression model. Compared to metoprolol, there was no statistically significant decrease in the risk of 90-day postoperative mortality with atenolol [adj. IRR (95% CI): 1.45 (0.89–2.37), p = 0.132], bisoprolol [adj. IRR (95% CI): 1.45 (0.89–2.37), p = 0.132], or other beta-blockers [adj. IRR (95% CI): 0.92 (0.46–1.85), p = 0.825]. In patients undergoing colon cancer surgery, the risk of 90-day postoperative mortality does not differ between the investigated types of β-adrenergic blocking agents.

Antihypertensive and cardioprotective effects of three generations of beta-adrenergic blockers: an historical perspective

There are currently, 3 generations of beta-adrenergic blockers for the treatment of hypertension and cardiovascular diseases. The 1^st generation caused vasoconstriction and bronchoconstriction due to β₁ + β₂ receptor blockade and unopposed α₁ receptors. The 2^nd generation of beta-blockers has lesser adverse effects than the 1^st generation with the 3^rd generation beta-blockers having much lesser effects than the other two generations. Current US and International guideline do not recommend beta-blockers as first line therapy of hypertension, but only in the presence of coronary artery disease or heart failure due to their lesser antihypertensive effect. These recommendations are disputed by several older and recent studies which have shown that the beta-blockers are effective and safe for the treatment of hypertension and could be used as first line therapy. To clarify this issue a Medline search of the English language literature was conducted between 2012 and 2021 and 30 pertinent papers were selected. The data from these studies show that the beta-blockers have inferior antihypertensive and stroke protective effect compared with the other classes of antihypertensive drugs and should be used as first line therapy only in patients with hypertension associated with coronary artery disease or heart failure. The information from these papers and collateral literature will be discussed in this perspective.

Nitric oxide in the Marfan vasculature: Friend or foe?

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the FBN1 gene, which encodes fibrillin-1, a protein essential for the formation and stabilization of elastic fibers as well as signaling homeostasis. Progressive aortic root widening is the most serious manifestation of MFS as it can lead to aortic dissection, aneurysm formation and rupture. However, despite their ability to decrease the hemodynamic stress the aorta is subjected to, anti-hypertensive medications often lead to underwhelming reductions in the rate of aortic root dilation, which illustrates how fragmental our understanding of MFS-associated aortic remodeling is. This manuscript summarizes recent evidence that document nitric oxide (NO) synthase (NOS)-related changes to the vasculature during the pathogenesis of MFS and how they result in a unique state of vascular dysfunction that likely plays a causal role in the aortic root widening process. We also review how clinic-approved and experimental therapies as well lifestyle approaches may promote aortic root stability by correcting NO homeostasis, which if properly optimized may improve outcomes in this population afflicted by a notoriously refractory type of aortopathy.

Meta-Analysis of the Usefulness of Beta-Blockers to Reduce the Risk of Major Adverse Cardiovascular Events in Patients With Stable Coronary Artery Disease Without Prior Myocardial Infarction or Left Ventricular Dysfunction

Beta-blockers (BBs) are the core of coronary artery disease (CAD) pharmacotherapy and demonstrated a well-established benefit in the treatment of acute myocardial infarction (MI). However, the prophylactic role of BBs to affect adverse outcomes in patients with stable CAD, especially among those without a pervious history of MI or left ventricular dysfunction, is not yet addressed. We aimed to determine the effects of beta-blockers on major adverse cardiovascular events (MACE) in patients with stable CAD without prior MI or left ventricular dysfunction. We searched PubMed, EMBASE, Web of Science, Scopus, Google Scholar, and Cochrane Controlled Trials Register for studies published from inception to March 31, 2021. Two researchers independently reviewed the database searches and selected eligible studies. A third reviewer was consulted whenever necessary. A total of 6 studies were included in the final analysis. BBs therapy did not reduce the risk of a MACE (HR, 1.05; 95% CI, 0.91 to 1.20), MI (HR, 1.13; 95% CI, 0.95 to 1.34), and cardiovascular death (HR, 0.95; 95% CI, 0.79 to 1.14). No statistically significant effect was observed between the participants on beta-blocker and control groups. In conclusion, our meta-analysis did not show the benefit of BBs in reducing MACE among patients with stable CAD without previous history of MI or left ventricular dysfunction.

The effect of beta-blockers on hemodynamic parameters in patient-specific blood flow simulations of type-B aortic dissection: a virtual study

Aortic dissection (AD) is one of the fatal and complex conditions. Since there is a lack of a specific treatment guideline for type-B AD, a better understanding of patient-specific hemodynamics and therapy outcomes can potentially control the progression of the disease and aid in the clinical decision-making process. In this work, a patient-specific geometry of type-B AD is reconstructed from computed tomography images, and a numerical simulation using personalised computational fluid dynamics (CFD) with three-element Windkessel model boundary condition at each outlet is implemented. According to the physiological response of beta-blockers to the reduction of left ventricular contractions, three case studies with different heart rates are created. Several hemodynamic features, including time-averaged wall shear stress (TAWSS), highly oscillatory, low magnitude shear (HOLMES), and flow pattern are investigated and compared between each case. Results show that decreasing TAWSS, which is caused by the reduction of the velocity gradient, prevents vessel wall at entry tear from rupture. Additionally, with the increase in HOLMES value at distal false lumen, calcification and plaque formation in the moderate and regular-heart rate cases are successfully controlled. This work demonstrates how CFD methods with non-invasive hemodynamic metrics can be developed to predict the hemodynamic changes before medication or other invasive operations. These consequences can be a powerful framework for clinicians and surgical communities to improve their diagnostic and pre-procedural planning.

Resting Heart Rate as a Cardiovascular Risk Factor in Hypertensive Patients: An Update

A large body of evidence has shown that resting heart rate (RHR) holds important prognostic information in several clinical conditions. In the majority of the general population studies, a graded association between RHR and mortality from all causes, cardiovascular (CV) disease, ischemic heart disease, and stroke has been observed. These associations appeared even stronger and more consistent in hypertensive patients. Studies performed with 24-hour ambulatory recording have shown that an elevated nighttime heart rate may confer an additional risk on top of office RHR. The mechanisms by which tachycardia alone or in association with sympathetic overactivity induces CV damage are well understood. Fast RHR is a strong predictor of future hypertension, metabolic disturbances, obesity, and diabetes. Several experimental lines of research point to high RHR as a main risk factor for the development of atherosclerosis, large artery stiffness, and CV disease. Elevated RHR is a common feature in patients with hypertension. Thus, there is a large segment of the hypertensive population that would benefit from a treatment able to decrease RHR. Improvement of unhealthy lifestyle should be the first goal in the management of the hypertensive patient with elevated RHR. Most clinical guidelines now recommend the use of combination therapies even in the initial treatment of hypertension. Although no results of clinical trials specifically designed to investigate the effect of RHR lowering in human beings without CV diseases are available, in hypertensive patients with high RHR a combination therapy including a cardiac slowing drug at optimized dose seems a sensible strategy. Tachycardia can be considered both as a marker of sympathetic overactivity and as a risk factor for cardiovascular events. In this sketch, the main cardiovascular and metabolic effects of increased sympathetic tone underlying high heart rate are shown. The link between tachycardia and cardiovascular events can be explained also by the direct hemodynamic action of heart rate on the arteries and the left ventricular (LV) wall.

Berries and Their Polyphenols as a Potential Therapy for Coronary Microvascular Dysfunction: A Mini-Review

Ischemia with no obstructive coronary artery disease (INOCA) is a common diagnosis with a higher prevalence in women compared to men. Despite the absence of obstructive coronary artery disease and no structural heart disease, INOCA is associated with major adverse cardiovascular outcomes as well a significant contributor to angina and related disability. A major feature of INOCA is coronary microvascular dysfunction (CMD), which can be detected by non-invasive imaging and invasive coronary physiology assessments in humans. CMD is associated with epicardial endothelial-dependent and -independent dysfunction, diffuse atherosclerosis, and left-ventricular hypertrophy, all of which lead to insufficient blood flow to the myocardium. Inflammatory and oxidative stress signaling, upregulation of the renin-angiotensin-aldosterone system and adrenergic receptor signaling are major drivers of CMD. Treatment of CMD centers around addressing cardiovascular risk factors; however, there are limited treatment options for those who do not respond to traditional anti-anginal therapies. In this review, we highlight the ability of berry-derived polyphenols to modulate those pathways. The evidence supports the need for future clinical trials to investigate the effectiveness of berries and their polyphenols in the treatment of CMD in INOCA patients.

The Association Between Hepatic Venous Pressure Gradient Baseline and the Response Rate of Carvedilol on Portal Hypertension

Objective: To assess the association between hepatic venous pressure gradient (HVPG) baseline and the response rate of cirrhotic in patients who received carvedilol treatment. Methods: In total 48 cirrhotic patients with a basic HVPG value greater than 12 mmHg were included (from July 2011 to October 2014). All patients received carvedilol treatment and underwent the second HVPG measurement 7 days later. In the following, all participants received an endoscopic variceal ligation (EVL) treatment. Results: HVPG was significantly reduced from 16.04 ± 3.10 to 12.76 ± 5.26 mmHg following carvedilol treatment. The response rate was about 58.33% (28/48). The response rate of the HVPG < 16 mmHg group (71.4%) was significantly higher than that of the HVPG ≥ 16 mmHg group (40%) (P < 0.05). Patients were followed up for a median of 26 months, ranged from 6 to 33 months. During the follow-up period (two years), the rebleeding rate was 9.97% and 49.56% in HVPG < 16 and HVPG ≥ 16 mmHg groups, respectively, with a statistically significant difference (P = 0.004). Also, the mortality rate (at 2 years) was 5.26% and 21.05%, respectively, which was significant (P = 0.035). Conclusions: This study demonstrated that the response rate of carvedilol on portal hypertension may be affected by the HVPG baseline, and the carvedilol was effective in reducing HVPG, especially for those with a HVPG < 16 mmHg.

The Effect of Nebivolol on Office Blood Pressure of Blacks Residing in Sub-Saharan Africa (A Pilot Study)

Introduction: There is substantial clinical evidence that monotherapy with beta-blockers are less effective in reducing blood pressure among hypertensive Black patients compared to Whites. The highly selective beta-1 agents like nebivolol and bisoprolol have, however, been reported to be effective in reducing blood pressure in African Americans. However, results in African Americans cannot be extrapolated to native Africans because of genetic admixture and gene-environment interaction. There is, therefore, the need for us to generate data that are applicable to Africans residing in sub-Saharan Africa. We therefore decided to evaluate the efficacy and tolerability of highly selective beta-1 agent nebivolol in hypertensive Black patients residing in sub-Saharan Africa. Materials and Methods: The nebivolol study was a multicenter, prospective, observational program among hypertensive patients with 4- and 8-week follow up which was conducted in 5 cities in Nigeria of Abuja, Calabar, Enugu, Oghara, and Port Harcourt. Dosages of nebivolol used in keeping with local prescribing information were 5 and 10 mg once daily each. The effectiveness of treatment was assessed by change from baseline in mean office systolic and diastolic blood pressures, and the proportion of patients achieving the therapeutic goal of <140/90 mmHg. Safety and tolerability of this medication were also assessed. Results: We report the results of the 140 patients studied. The mean age and body mass index were 46.9 ± 7.3 years and 22.3 ± 5.8 kg/m², respectively, and 57.1% were female. Nebivolol reduced SBP and DBP by 7.6 and 6.6 mmHg, respectively, in 4 weeks, and by 11.1 and 8.0 mm Hg, respectively, in 8 weeks. Blood pressure control was achieved in 54.8% of the patients in 4 weeks and increased to 60.4% in 8 weeks. There was no change in metabolic profile between randomization and at 8 weeks, and erectile dysfunction occurred in 1.3% of the study population. Conclusions: Nebivolol 5 and 10 mg appear efficacious in Nigerian Africans with no negative metabolic effect and minimal side effect profile. Clinical Trial Registration: www.ClinicalTrials.gov, Study Identification: NCT03598673.

Comparison of the Apnea-Hypopnea Index Determined by a Peripheral Arterial Tonometry-Based Device With That Determined by Polysomnography - Results From a Multicenter Study

Background: Sleep disordered breathing (SDB) is prevalent and associated with increased mortality in patients both with and without cardiovascular disease (CVD). Many portable monitoring devices, including peripheral arterial tonometry (PAT)-based devices, have been developed. Although previous studies have demonstrated that the apnea-hypopnea index (AHI) determined by PAT devices (pAHI) is strongly correlated with AHI determined by polysomnography (AHI-PSG), no data have been reported from a Japanese patient population or patients with CVD. In this study we compared the parameters determined by PAT-based devices with those determined by polysomnography in Japanese patients with CVD.

Methods and Results: We enrolled 120 patients undergoing overnight polysomnography at 6 Japanese centers. A PAT-based device was used simultaneously with polysomnography. Polysomnography recordings were scored centrally by a technician in a blinded manner. PAT-based device recordings were scored using an automatic algorithm. There was a strong correlation between pAHI and AHI-PSG (r=0.896; P<0.001) with acceptable agreement. The strong correlation between pAHI and AHI-PSG was observed in patients with CVD (n=55; P=0.849; P<0.001) and without CVD (n=65; r=0.927; P<0.001). The presence or absence of CVD did not affect the relationship between pAHI and AHI-PSG (P=0.225).

Conclusions: A PAT-based device provides a reliable AHI in a Japanese patient population, even in patients with CVD. These findings may help reduce the number of patients with undiagnosed SDB and CVD.

Epidural anesthesia and hypotension in pheochromocytoma and paraganglioma

Postoperative hypotension frequently occurs after resection of pheochromocytoma and/or paraganglioma (PPGLs). Epidural anesthesia (EA) is often used for pain control in open resection of these tumors; one of its side effects is hypotension. Our aim is to determine if EA is associated with an increased risk of postoperative hypotension after open resection of PPGLs. We conducted a retrospective review of patients who underwent open resection of PPGLs at the National Institutes of Health from 2004 to 2019. Clinical and perioperative parameters were analyzed by the use of EA. The primary endpoint was postoperative hypotension. Ninety-seven patients (46 female and 51 male; mean age, 38.5 years) underwent open resection of PPGLs and 69 (71.1%) received EA. Patients with EA had a higher rate beta-blocker use (79.7% vs 57.1%, P = 0.041), metastasis (69.6% vs 39.3%, P = 0.011), and were more frequently hypotensive after surgery (58.8% vs 25.0%, P = 0.003) compared to those without EA. Patients with postoperative hypotension had higher plasma normetanephrines than those without (7.3 fold vs 4.1 fold above the upper limit of normal, P = 0.018). Independent factors associated with postoperative hypotension include the use of beta-blockers (HR = 3.35 (95% CI: 1.16-9.67), P = 0.026) and EA (HR = 3.49 (95% CI: 1.25-9.76), P = 0.017). Data from this retrospective study suggest that, in patients with open resection of PPGLs, EA is an independent risk factor for early postoperative hypotension. Special caution is required in patients on beta-blockade. A prospective evaluation with standardized protocols for the use of EA and management of hemodynamic variability is necessary.

Synthesis, Molecular Modeling of Novel Substituted Pyridazinones and their Vasorelaxant Activities

BACKGROUND

Hypertension, one of the most common cardiovascular diseases that can cause coronary disease, stroke, myocardial infarction, and sudden death, it is the major contributor to cardiac failure as well as renal insufficiency.

OBJECTIVES

As there are many cardio-active pyridazinone-base derivatives in clinical use, therefore, we aimed to synthesize a new series of pyridazin-3-ones and evaluate their vasorelaxant activity.

METHODS

A new series of synthesized compounds were carried out first by the synthesis of 6- flouroarylpyridazinones by cyclization of 3-(4-flourobenzoyl) propionic acid with hydrazine hydrate or arylhydrazines to provide the corresponding pyridazinone derivatives 2a-d. Mannich reaction was performed using morpholine or piperidine formaldehyde to obtain compounds 3a,b. On the other hand, reaction of 2a with various chloroacetamide intermediates, in dimethylformamide and potassium carbonate as a catalyst, afforded the target compounds 5a-c. The aromatic acid hydrazide intermediates 6a-g were prepared in 50-90% yield, by reacting to the prepared esters with hydrazine hydrate under reflux in ethanol. The two compounds 8a,b were prepared via condensation of 7a,b with ethyl chloroacetate in dry acetone. Finally, the target 2,4,6-trisubstituted pyridazinones 9a-c derivatives were obtained by the reaction of 7a with the appropriate aromatic aldehyde or substituted acetophenones. The new compounds were then evaluated for their vasorelaxant properties using isolated thoracic rat aortic rings. In addition, a homology model was built and molecular modeling simulation of these compounds into the active sites of the newly created α1a-adrenoceptor model was performed in order to predict and rationalize their affinities toward this receptor.

RESULTS

Among these compounds; 5a was the most potent, it exhibited approximately two-times the activity of prazosin (IC50 = 0.250, 0.487 mmol, respectively) also, fourteen compounds were more potent than prazosin.

Comparison of the Effects of Metoprolol and Bisoprolol on Lipid and Glucose Profiles in Cardiovascular Patients

BACKGROUND

Cardioselective beta-blockers may affect glucose or lipid profiles.

OBJECTIVE

We sought to compare the effects of two beta-blockers, metoprolol and bisoprolol, as the most commonly used drugs in cardiology, on glucose and lipid profiles in patients with cardiovascular diseases.

METHODS

We conducted a retrospective cross-sectional matched study at Prince Sultan Cardiac Center in Burydah in August 2017. Patient records were screened, and adult patients with cardiovascular disorders who were treated with a stable dose of metoprolol or bisoprolol were included. Parameters related to glucose and lipid metabolism were compared using the Student's t-test between the two groups.

RESULTS AND CONCLUSION

The metoprolol and bisoprolol arms included 204 and 200 patients, respectively.

Risk of Hospitalization for Cardiovascular Events with β-Blockers in Hypertensive Patients: A Retrospective Cohort Study

INTRODUCTION

β-Blockers are a heterogenous class of drugs that are no longer recommended for initial antihypertension monotherapy due to unfavorable long-term cardiovascular events observed with non-vasodilatory β-blockers. However, the comparative cardiovascular event risk between the vasodilatory β1-selective antagonist/β3 agonist nebivolol and non-vasodilatory β1-blockers, atenolol and metoprolol, is unknown.

METHODS

Incident nebivolol, atenolol, or metoprolol monotherapy users with hypertension were identified using US claims data (2007-2014). The first β-blocker claim on/after 1/1/2008 defined the index drug/date. Hypertensive patients without pre-index cardiovascular history were followed until index drug discontinuation (> 90 day supply gap), use of other β-blockers, or end of continuous plan enrollment. Patients were pair-wise propensity score-matched using logistic regression, adjusted for baseline demographics, Charlson Comorbidity Index score, comorbid chronic pulmonary disease, rheumatic disease, renal disease, and diabetes, and use of other antihypertensive drugs during baseline. Time to first hospital claim for a cardiovascular event was assessed via Cox proportional hazards regression, adjusted for the variables above.

RESULTS

Inclusion criteria were met by 81,402 patients (n = 27,134 in each matched treatment cohort), with no between-cohort differences in baseline characteristics, comorbid conditions, or average follow-up duration. Atenolol and metoprolol cohorts had greater risk of hospitalization for a composite event (myocardial infarction, angina, congestive heart failure, stroke) than nebivolol users (adjusted hazard ratios [95% confidence interval] atenolol: 1.68 [1.29, 2.17]; metoprolol: 2.05 [1.59, 2.63]; P < 0.001, both). Risks of most individual cardiovascular events were also lower with nebivolol, including myocardial infarction and angina versus atenolol, and myocardial infarction, congestive heart failure, and angina versus metoprolol (P < 0.05, all).

CONCLUSIONS

Nebivolol was associated with significantly lower risk of hospitalization due to composite cardiovascular events than atenolol or metoprolol in this large retrospective cohort study of monotherapy with three different β1-selective blockers in hypertensive patients.

FUNDING

Allergan plc, Madison, NJ, USA.

Therapeutic Targets for Treatment of Heart Failure: Focus on GRKs and β-Arrestins Affecting βAR Signaling

Heart failure (HF) is a heart disease that is classified into two main types: HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Both types of HF lead to significant risk of mortality and morbidity. Pharmacological treatment with β-adrenergic receptor (βAR) antagonists (also called β-blockers) has been shown to reduce the overall hospitalization and mortality rates and improve the clinical outcomes in HF patients with HFrEF but not HFpEF. Although, the survival rate of patients suffering from HF continues to drop, the management of HF still faces several limitations and discrepancies highlighting the need to develop new treatment strategies. Overstimulation of the sympathetic nervous system is an adaptive neurohormonal response to acute myocardial injury and heart damage, whereas prolonged exposure to catecholamines causes defects in βAR regulation, including a reduction in the amount of βARs and an increase in βAR desensitization due to the upregulation of G protein-coupled receptor kinases (GRKs) in the heart, contributing in turn to the progression of HF. Several studies show that myocardial GRK2 activity and expression are raised in the failing heart. Furthermore, β-arrestins play a pivotal role in βAR desensitization and, interestingly, can mediate their own signal transduction without any G protein-dependent pathway involved. In this review, we provide new insight into the role of GRKs and β-arrestins on how they affect βAR signaling regarding the molecular and cellular pathophysiology of HF. Additionally, we discuss the therapeutic potential of targeting GRKs and β-arrestins for the treatment of HF.

Sympathetic overactivity in dialysis patients-Underappreciated and clinically consequential

Cardiovascular morbidity and mortality remain frustratingly common in dialysis patients. A dearth of established evidence-based treatment calls for alternative therapeutic avenues to be embraced. Sympathetic hyperactivity, predominantly due to afferent nerve signaling from the diseased native kidneys, has been established to be prognostic in the dialysis population for over 15 years. Despite this, tangible therapeutic interventions have, to date, been unsuccessful and the outlook for patients remains poor. This narrative review summarizes established experimental and clinical data, highlighting recent developments, and proposes why interventions to ameliorate sympathetic hyperactivity may well be beneficial for this high-risk population.

Nebivolol/Valsartan: A Novel Antihypertensive Fixed-Dose Combination Tablet

Data Sources: A PubMed (1966 to October 2018) search was conducted using the following keywords: nebivolol, valsartan, and hypertension (HTN). Additional sources were identified by references. Study Selection and Data Extraction: Articles written in English were included if they evaluated the pharmacology, pharmacokinetics, efficacy, safety, or place in therapy of nebivolol/valsartan in human subjects. Data Synthesis: Most patients with HTN require combination therapy; however, β-adrenergic antagonists and AII type 1 receptor blockers have been considered less effective because of overlapping mechanisms of action. A phase III, randomized trial demonstrated that nebivolol/valsartan produced statistically significant blood pressure (BP) lowering as compared with monotherapy with the individual components or placebo. Substudy analyses confirmed this among subgroups and demonstrated that nebivolol/valsartan decreased plasma renin and aldosterone levels. One trial reported continued BP lowering at 52 weeks. Another study showed that nebivolol/valsartan had similar additivity scores as compared with other antihypertensive combinations. Relevance to Patient Care and Clinical Practice: This review discusses drug information, efficacy, and safety of nebivolol/valsartan and discusses its clinical relevance as a novel combination product in managing patients with HTN. Conclusion: Nebivolol/valsartan combination may offer a benefit to patients with an indication for both classes who desire to decrease pill burden. Although BP lowering was statistically significant in comparison to the individual components as monotherapy, the combination does not offer clinically significant benefits that would elevate its place in HTN management.

Systemic blood pressure at exercise in hypoxia in hypertensive and normotensive patients

OBJECTIVES

The current study aimed to determine whether acute hypoxia exposure in laboratory conditions associated with exercise induces an increase in systemic blood pressure (BP) in normotensive and hypertensive patients, and whether hypertensive patients are more prone to develop severe acute mountain sickness (sAMS). Finally, to determine if BP changes at exercise in acute hypoxia in hypertensive patients are predictive factors for sAMS.

METHODS

From 2012 to 2015, 852 normotensive and 106 hypertensive patients went through an acute hypoxia exercise test before a sojourn at high altitude. A subgroup of 228 normotensive was selected to match age, sex ratio, body weight and BMI and compared with the hypertensive group.

RESULTS

In normotensive and hypertensive patients, for a given workload, BP was higher in hypoxia than in normoxia, whereas, for a given heart rate, it was lower in hypoxia than in normoxia. Hypertensive patients treated by beta-blockers showed lower arterial oxygen saturation (vs. other treatments) and blunted cardiac and ventilatory responses to hypoxia at exercise. Based on questionnaires filled out at high altitude, hypertensive patients were not more prone than normotensive patients to develop sAMS. During the laboratory acute hypoxic exercise test, hypertensive patients suffering from sAMS, although taking acetazolamide showed similar BP than hypertensive patients without sAMS and without acetazolamide.

DISCUSSION AND CONCLUSION

We hypothesize that acute hypoxia with exercise in laboratory conditions induces a peripheral vasodilation that balances vasoconstriction and tachycardia centrally induced through the adrenergic system. Hypertensive and normotensive patients behave similarly during exercise in acute hypoxia. Acute hypoxia does not exacerbate the exercise-induced increase in BP. BP variation, during the acute hypoxia exercise test, is not a useful predictor of intolerance to high altitude. Based on laboratory tests in acute hypoxia, hypertensive patients may not be at higher risk to develop sAMS at high altitude.

Rationale for nebivolol/valsartan combination for hypertension: review of preclinical and clinical data

To treat hypertension, combining two or more antihypertensive drugs from different classes is often necessary. β-Blockers and renin–angiotensin–aldosterone system inhibitors, when combined, have been deemed ‘less effective’ based on partially overlapping mechanisms of action and limited evidence. Recently, the single-pill combination (SPC) of nebivolol (Neb) 5 mg – a vasodilatory β1-selective antagonist/β3 agonist – and valsartan 80 mg, an angiotensin II receptor blocker, was US Food and Drug Administration-approved for hypertension. Pharmacological profiles of Neb and valsartan, alone and combined, are well characterized. In addition, a large 8-week randomized trial in stages I–II hypertensive patients (N = 4161) demonstrated greater blood pressure-reducing efficacy for Neb/valsartan SPCs than component monotherapies with comparable tolerability. In a biomarkers substudy (N = 805), Neb/valsartan SPCs prevented valsartan-induced increases in plasma renin, and a greater reduction in plasma aldosterone was observed with the highest SPC dose vs. valsartan 320 mg/day. This review summarizes preclinical and clinical evidence supporting Neb/valsartan as an efficacious and well tolerated combination treatment for hypertension.

Beta blockers in patients with end-stage renal disease-Evidence-based recommendations

For patients who require hemodialysis, beta blockers offer a simultaneous opportunity and challenge in the treatment of cardiovascular disease. Beta blockers are well supported by data from nondialysis populations and directly mitigate the sympathetic overactivity that links chronic kidney disease with cardiovascular sequelae. However, the evidence supporting their use in patients receiving hemodialysis is sparse and the heterogeneity of the beta blocker class makes it difficult to prescribe these medications with confidence. Despite these limitations, both trial and observational data exist that can help guide the use of these medications. In this review, we outline the reasons to consider beta blockers for patients receiving hemodialysis, discuss the barriers to their use, and provide specific evidence-based recommendations for beta blocker use in patients with heart failure, hypertension, ischemic heart disease and arrhythmia.

Additivity of nebivolol/valsartan single-pill combinations versus other single-pill combinations for hypertension

The single‐pill combination (SPC) comprising nebivolol (5 mg), a vasodilatory β₁‐selective antagonist/β₃‐agonist, and valsartan (80 mg), a renin‐angiotensin‐aldosterone system inhibitor, is the only Food and Drug Administration–approved β‐blocker/renin‐angiotensin‐aldosterone system inhibitor SPC for hypertension. Additive effects of four nebivolol/valsartan SPC doses (5 mg/80 mg, 5/160 mg, 10/160 mg, 10/320 mg nebivolol/valsartan) were compared with five Food and Drug Administration–approved non–β‐blocker/renin‐angiotensin‐aldosterone system inhibitor SPCs (aliskiren/hydrochlorothiazide, aliskiren/amlodipine, valsartan/amlodipine, aliskiren/valsartan, and telmisartan/amlodipine). Additivity is the ratio of placebo‐adjusted SPC blood pressure (BP) reduction to the placebo‐adjusted monotherapy component BP reduction sums. A weighted average of comparator scores was calculated and compared vs nebivolol/valsartan. Additivity ratio scores for nebivolol/valsartan SPCs (diastolic BP range: 0.735–0.866; systolic BP range: 0.717–0.822) were similar to the comparator weighted average (diastolic BP: 0.837; systolic BP: 0.825). Among the nebivolol/valsartan SPCs, 5/80 mg had the greatest additivity (diastolic BP: 0.866; systolic BP: 0.822). BP reduction contributions with monotherapy were similar for nebivolol/valsartan 5/80 mg SPC. Additivity scores for nebivolol/valsartan and select non–β‐blocker/renin‐angiotensin‐aldosterone system inhibitor SPCs were comparable.

Enantioselective determination of 1-[4-(2-methoxyethyl)phenoxy]-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanol hydrochloride, a novel antihypertensive agent, in rat plasma and tissues by liquid chromatography-tandem mass spectrometry

Enantioselective biodistribution studies of 1-[4-(2-methoxyethyl)phenoxy]-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanol hydrochloride (TJ0711), a novel antihypertensive agent, require the accurate and precise quantification of each TJ0711 enantiomer in biological fluids and tissues. Here we report a simple and sensitive liquid chromatography with tandem mass spectrometry method for simultaneous determination of (R)-TJ0711 and (S)-TJ0711 in rat plasma and tissue samples using protein precipitation. The influence of column type, temperature, mobile phase composition, and flow rate on the retention and enantioselectivity was evaluated. The separation of the TJ0711 enantiomers was ultimately achieved on a SUMICHIRAL OA-2500 column in 15 min using isocratic elution with ethanol/hexane (40:60) at a flow rate of 0.8 mL/min. Good linearities of spiked analyte concentration from 5 to 2000 ng/mL were achieved and the correlation coefficients (R) were greater than 0.99. The intra- and inter-day accuracy and precision for both analytes were <15% at all concentration levels, and the extraction recoveries were consistent among the five quality control concentrations. This assay was successfully applied to quantify plasma and tissue concentrations of TJ0711 enantiomers in a preclinical study.

Beta-blockers for hypertension

BACKGROUND

Beta-blockers refer to a mixed group of drugs with diverse pharmacodynamic and pharmacokinetic properties. They have shown long-term beneficial effects on mortality and cardiovascular disease (CVD) when used in people with heart failure or acute myocardial infarction. Beta-blockers were thought to have similar beneficial effects when used as first-line therapy for hypertension. However, the benefit of beta-blockers as first-line therapy for hypertension without compelling indications is controversial. This review is an update of a Cochrane Review initially published in 2007 and updated in 2012.

OBJECTIVES

To assess the effects of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to June 2016: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 6), MEDLINE (from 1946), Embase (from 1974), and ClinicalTrials.gov. We checked reference lists of relevant reviews, and reference lists of studies potentially eligible for inclusion in this review, and also searched the the World Health Organization International Clinical Trials Registry Platform on 06 July 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year of duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate, resolving discrepancies by consensus. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and conducted fixed-effect or random-effects meta-analyses, as appropriate. We also used GRADE to assess the certainty of the evidence. GRADE classifies the certainty of evidence as high (if we are confident that the true effect lies close to that of the estimate of effect), moderate (if the true effect is likely to be close to the estimate of effect), low (if the true effect may be substantially different from the estimate of effect), and very low (if we are very uncertain about the estimate of effect).

MAIN RESULTS

Thirteen RCTs met inclusion criteria. They compared beta-blockers to placebo (4 RCTs, 23,613 participants), diuretics (5 RCTs, 18,241 participants), calcium-channel blockers (CCBs: 4 RCTs, 44,825 participants), and renin-angiotensin system (RAS) inhibitors (3 RCTs, 10,828 participants). These RCTs were conducted between the 1970s and 2000s and most of them had a high risk of bias resulting from limitations in study design, conduct, and data analysis. There were 40,245 participants taking beta-blockers, three-quarters of them taking atenolol. We found no outcome trials involving the newer vasodilating beta-blockers (e.g. nebivolol).There was no difference in all-cause mortality between beta-blockers and placebo (RR 0.99, 95% CI 0.88 to 1.11), diuretics or RAS inhibitors, but it was higher for beta-blockers compared to CCBs (RR 1.07, 95% CI 1.00 to 1.14). The evidence on mortality was of moderate-certainty for all comparisons.Total CVD was lower for beta-blockers compared to placebo (RR 0.88, 95% CI 0.79 to 0.97; low-certainty evidence), a reflection of the decrease in stroke (RR 0.80, 95% CI 0.66 to 0.96; low-certainty evidence) since there was no difference in coronary heart disease (CHD: RR 0.93, 95% CI 0.81 to 1.07; moderate-certainty evidence). The effect of beta-blockers on CVD was worse than that of CCBs (RR 1.18, 95% CI 1.08 to 1.29; moderate-certainty evidence), but was not different from that of diuretics (moderate-certainty) or RAS inhibitors (low-certainty). In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95% CI 1.11 to 1.40; moderate-certainty evidence) and RAS inhibitors (RR 1.30, 95% CI 1.11 to 1.53; moderate-certainty evidence). However, there was little or no difference in CHD between beta-blockers and diuretics (low-certainty evidence), CCBs (moderate-certainty evidence) or RAS inhibitors (low-certainty evidence). In the single trial involving participants aged 65 years and older, atenolol was associated with an increased CHD incidence compared to diuretics (RR 1.63, 95% CI 1.15 to 2.32). Participants taking beta-blockers were more likely to discontinue treatment due to adverse events than participants taking RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; moderate-certainty evidence), but there was little or no difference with placebo, diuretics or CCBs (low-certainty evidence).

AUTHORS' CONCLUSIONS

Most outcome RCTs on beta-blockers as initial therapy for hypertension have high risk of bias. Atenolol was the beta-blocker most used. Current evidence suggests that initiating treatment of hypertension with beta-blockers leads to modest CVD reductions and little or no effects on mortality. These beta-blocker effects are inferior to those of other antihypertensive drugs. Further research should be of high quality and should explore whether there are differences between different subtypes of beta-blockers or whether beta-blockers have differential effects on younger and older people.

Synthesis and Determination of Physicochemical Properties of New 3-(4-Arylpiperazin-1-yl)-2-hydroxypropyl 4-Alkoxyethoxybenzoates

Nine new dihydrochloride salts of 3-(4-arylpiperazin-1-yl)-2-hydroxypropyl 4-alkoxyethoxybenzoates were designed and synthesized. The physicochemical properties such as lipophilicity index (log k_w) and dissociation constant (pK_a) were experimentally determined and compared to the software calculated data. The lipophilicity index was determined by means of reversed-phase high performance liquid chromatography (RP-HPLC). The pK_a values were determined by means of capillary zone electrophoresis. The "drug-likeness" properties according to the Lipinski Rule of Five and prediction of possible blood-brain barrier penetration were computed and discussed.

Different associations between beta-blockers and other antihypertensive medication combinations with brachial blood pressure and aortic waveform parameters

BACKGROUND

Comparing the relationships of antihypertensive medications with brachial blood pressure (BP) and aortic waveform parameters may help clinicians to predict the effect on the latter in brachial BP-based antihypertensive therapy. We aimed to make such comparisons with new waveform measures and a wider range of antihypertensive regimens than examined previously.

METHODS

Cross-sectional analysis of 2933 adults (61% male; aged 50-84years): 1637 on antihypertensive treatment and 1296 untreated hypertensives. Sixteen medicine regimens of up to 4 combinations of drugs from 6 antihypertensive classes were analysed. Aortic systolic BP, augmentation index (AIx), excess pressure integral (EPI), backward pressure amplitude (Pb), reflection index (RI) and pulse wave velocity (PWV) were calculated from aortic pressure waveforms derived from suprasystolic brachial measurement.

RESULTS

Forest plots of single-drug class comparisons across regimens with the same number of drugs (for between 1- and 3-drug regimens) revealed that AIx, Pb, RI and/or loge(EPI) were higher (maximum difference=5.6%, 2.2mmHg, 0.0192 and 0.13 loge(mmHg⋅s), respectively) with the use of a beta-blocker compared with vasodilators and diuretics, despite no brachial systolic and diastolic BP differences. These differences were reduced (by 34-57%) or eliminated after adjustment for heart rate, and similar effects occurred when controlling for systolic ejection period or diastolic duration.

CONCLUSIONS

Beta-blocker effects on brachial BP may overestimate effects on aortic waveform parameters. Compared to other antihypertensives, beta-blockers have weaker associations with wave reflection measures and EPI; this is predominantly due to influences on heart rate.

Pharmacologic Treatment of Pediatric Hypertension

Prevalence of hypertension is increasing in children and adolescents. Uncontrolled hypertension in children not only causes end organ damage but also increases the risk of adult hypertension and cardiovascular disease. Clinical trials have proven efficacy of antihypertensive medications in children. These medications are well tolerated by children with acceptable safety profile. The choice of agent is usually driven by underlying etiology of hypertension, profile of its side effects, and clinician's preference. This article will review currently available pediatric data on mechanism of action, common adverse effects, pediatric indication, recent clinical trial, and newer drugs in the common classes of antihypertensive medications.

Effects of β-Blockers With and Without Vasodilating Properties on Central Blood Pressure

β-Blockers are less effective than other antihypertensive drug classes in reducing central systolic blood pressure (cSBP) as compared with peripheral SBP (pSBP). Whether this effect is less pronounced with vasodilating β-blockers (VBB) when compared with nonvasodilating β-blockers (NVBB) remains unsettled. We conducted a systematic review and meta-analysis of randomized trials exploring the effects of β-blockers on both pSBP and cSBP in hypertension. We selected 20 studies, for a total of 32 treatment arms (n=21 for NVBB, n=11 for VBB) and 1263 participants (n=962 for NVBB, n=301 for VBB). pSBP decreased from 150 to 133 mm Hg for NVBB and from 145 to 134 mm Hg for VBB. cSBP decreased from 137 to 126 mm Hg for NVBB and from 132 to 123 mm Hg for VBB. SBP amplification (pSBP–cSBP) decreased significantly under VBB (−5.6 mm Hg; 95% confidence interval, −7.8, −3.4 mm Hg), but not under NVBB (−1.1 mm Hg; 95% confidence interval, −3.4, +1.2 mm Hg; P <0.01 versus NVBB). There was high heterogeneity both within and between β-blockers subclasses. In a meta-regression model, the weighted difference in treatment-induced changes in SBP amplification between NVBB and VBB lost its significance after adjustment for mean age and baseline pSBP and heart rate (−2.9±2.3 mm Hg; P =0.22) and was almost abolished after adjustment for treatment-induced heart rate changes (−0.1±0.5 mm Hg; P =0.78). In conclusion, NVBBs, but not VBBs, determine a lower reduction in cSBP than in pSBP. However, the difference in treatment-induced SBP amplification changes between NVBB and VBB is nearly abolished after accounting for differences in heart rate changes.

Recruitment of β-arrestin 1 and 2 to the β2-adrenoceptor: analysis of 65 ligands

Beyond canonical signaling via Gαs and cAMP, the concept of functional selectivity at β2-adrenoceptors (β2ARs) describes the ability of adrenergic drugs to stabilize ligand-specific receptor conformations to initiate further signaling cascades comprising additional G-protein classes or β-arrestins (βarr). A set of 65 adrenergic ligands including 40 agonists and 25 antagonists in either racemic or enantiopure forms was used for βarr recruitment experiments based on a split-luciferase assay in a cellular system expressing β2AR. Many agonists showed only (weak) partial agonism regarding βarr recruitment. Potencies and/or efficacies increased depending on the number of chirality centers in (R) configuration; no (S)-configured distomer was more effective at inducing βarr recruitment other than the eutomer. βarr2 was recruited more effectively than βarr1. The analysis of antagonists revealed no significant effects on βarr recruitment. Several agonists showed preference for activation of Gαs GTPase relative to βarr recruitment, and no βarr-biased ligand was identified.

IN CONCLUSION

1) agonists show strong bias for Gαs activation relative to βarr recruitment; 2) agonists recruit βarr1 and βarr2 with subtle differences; and 3) there is no evidence for βarr recruitment by antagonists.

A Review of Nebivolol Pharmacology and Clinical Evidence

Nebivolol is a highly selective β1-adrenergic receptor antagonist with a pharmacologic profile that differs from those of other drugs in its class. In addition to cardioselectivity mediated via β1 receptor blockade, nebivolol induces nitric oxide-mediated vasodilation by stimulating endothelial nitric oxide synthase via β3 agonism. This vasodilatory mechanism is distinct from those of other vasodilatory β-blockers (carvedilol, labetalol), which are mediated via α-adrenergic receptor blockade. Nebivolol is approved for the treatment of hypertension in the US, and for hypertension and heart failure in Europe. While β-blockers are not recommended within the current US guidelines as first-line therapy for treatment of essential hypertension, nebivolol has shown comparable efficacy to currently recommended therapies in lowering peripheral blood pressure in adults with hypertension with a very low rate of side effects. Nebivolol also has beneficial effects on central blood pressure compared with other β-blockers. Clinical data also suggest that nebivolol may be useful in patients who have experienced erectile dysfunction while on other β-blockers. Here we review the pharmacological profile of nebivolol, the clinical evidence supporting its use in hypertension as monotherapy, add-on, and combination therapy, and the data demonstrating its positive effects on heart failure and endothelial dysfunction.

Labetalol Prevents Intestinal Dysfunction Induced by Traumatic Brain Injury

Background

Beta-adrenergic blockade has been hypothesized to have a protective effect on intestinal dysfunction and increased intestinal permeability associated with the epinephrine surge after traumatic brain injury (TBI).

Methods

Wister rats were subjected to either a weight drop TBI, and intraperitoneally injected or not with labetalol, or a sham procedure (18 rats per group). After 3, 6, or 12h (6 rats per subgroup), intestinal permeability to 4.4 kDa FITC-Dextran and plasma epinephrine levels were measured as was intestinal tight junction protein ZO-1 expression at 12h. Terminal ileum was harvested to measure levels of intestinal tumor necrosis factor (TNF)-α and to evaluate histopathology.

Results

In TBI group vs. sham group, intestinal permeability (P<0.01) was significantly higher at all time-points, and intestinal ZO-1 expression was lower at 12h. In TBI with vs. without labetalol group, 1) intestinal permeability was significantly lower at 6 and 12h (94.31±7.64 vs. 102.16±6.40 μg/mL; 110.21±7.52 vs. 118.95±7.11 μg/mL, respectively); 2) levels of plasma epinephrine and intestinal TNF-α were significantly lower at 3, 6 and 12h; and 3) intestinal ZO-1 expression was higher at 3, 6 and 12h (p=0.018). Histopathological evaluation showed that labetalol use preserved intestinal architecture throughout.

Conclusion

In a rat model of TBI, labetalol reduced TBI-induced sympathetic hyperactivity, and prevented histopathological intestinal injury accompanied by changes in gut permeability and gut TNF-α expression.

Aromatic Amines Exert Contrasting Effects on the Anticoagulant Effect of Acetaldehyde upon APTT

The pharmacological effects of amphetamine, procaine, procainamide, DOPA, isoproterenol, and atenolol upon activated partial thromboplastin time in the absence and presence of acetaldehyde have been investigated. In the absence of acetaldehyde, amphetamine and isoproterenol exhibit a procoagulant effect upon activated partial thromboplastin time, whereas atenolol and procaine display anticoagulant effects upon activated partial thromboplastin time. DOPA and procainamide do not alter activated partial thromboplastin time. Premixtures of procaine with acetaldehyde produce an additive anticoagulant effect on activated partial thromboplastin time, suggesting independent action of these compounds upon clotting factors. Premixtures of amphetamine with acetaldehyde, as well as atenolol with acetaldehyde, generate a detoxication of the anticoagulant effect of acetaldehyde upon activated partial thromboplastin time. A similar statistically significant decrease in activated partial thromboplastin time is seen when procainamide is premixed with acetaldehyde for 20 minutes at room temperature. Premixtures of DOPA and isoproterenol with acetaldehyde do not affect an alteration in activated partial thromboplastin time relative to acetaldehyde alone. Hence, a selective interaction of atenolol, procaine, and amphetamine with acetaldehyde to produce detoxication of the acetaldehyde is suggested, undoubtedly due to the presence of amino, hydroxyl, or amide groups in these drugs.

The nitric oxide/soluble cyclic guanylase/cyclic guanosine monophosphate pathway is involved in the cardiovascular effects of a novel α1- and β-adrenoceptor antagonist

The compound MH-78 ((+/-)-1-(2,6-dimethylphenoxy)-3-{4-[2-(2-methoxyphenoxy)ethyl]-piperazin-1-yl}propan-2-ol dihydrochloride) contains structural elements that are typical for α1- and β-blockers. This study aimed to investigate the hypotensive activity as well as the in vitro and in vivo cardiovascular effects of a novel α1- and β-adrenoceptor antagonist (MH-78) and compare it with carvedilol and urapidil. The procedures were performed on aortic rings of normotensive anesthetized rats. MH-78 decreased the blood pressure and heart rate after intravenous and oral administration. MH-78 possesses both α1- and β-adrenoceptor blocking activity, which was confirmed in the in vivo study. In biofunctional assays, MH-78 displayed vasorelaxant activity due to α1-adrenoceptor antagonism and calcium channel blocking properties. Moreover, in endothelium-intact aortic rings, pretreatment with Nω-nitro-L-arginine methyl ester (L-NAME) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) reduced the MH-78-induced vasorelaxation to a level that is characteristic for MH-78 affinity to α1-adrenoceptors. Our results demonstrated that MH-78 possesses α1- and β-adrenoceptor blocking properties and induces potent hypotensive and vasorelaxant effects. Moreover, it relaxes vascular smooth muscle not only due to α1-adrenoceptor blocking activity, but also via the endothelium-dependent nitric oxide/soluble guanylyl cyclase/cyclic guanosine monophosphate signalling pathway.

Clinical utility of fixed-dose combinations in hypertension: evidence for the potential of nebivolol/valsartan

Despite significant advances in pharmacologic approaches to treat hypertension during the last decades, hypertension- and hypertension-related organ damage are still a high health and economic burden because a large proportion of patients with hypertension do not achieve optimal blood pressure control. There is now general agreement that combination therapy with two or more antihypertensive drugs is required for targeted blood pressure accomplishment and reduction of global cardiovascular risk. The goals of combination therapies are to reduce long-term cardiovascular events by targeting different mechanism underlying hypertension and target organ disease, to block the counterregulatory pathways activated by monotherapies, to improve tolerability and decrease the adverse effects of up-titrated single agents, and to increase persistence and adherence with antihypertensive therapy. Multiple clinical trials provide evidence that fixed-dose combinations in a single pill offer several advantages when compared with loose-dose combinations. This review discusses the advances in hypertension control and associated cardiovascular disease as they relate to the prospect of combination therapy targeting a third-generation beta (β) 1-adrenergic receptor (nebivolol) and an angiotensin II receptor blocker (valsartan) in fixed-dose single-pill formulations.

Anti-hypertensive drugs in children and adolescents

Worldwide the prevalence of essential hypertension in children and adolescents continues to increase. Traditionally providers have used “off-label” drugs to treat pediatric hypertension, meaning that rigorous clinical trials of these drugs have not been specifically performed in pediatric patient populations. Consequently providers have extrapolated dosing, safety and efficacy from trials in adults. This practice is sub-optimal as children demonstrate unique differences in drug metabolism and response. Use of unstudied or understudied drugs increases risk of adverse events and/or can lead to sub-optimal efficacy. Recognizing these concerns, regulatory agencies have created financial incentives for industry to conduct pediatric clinical trials. These incentives, coupled with the emerging pediatric hypertension epidemic, have spurred over 30 clinical trials of anti-hypertensive drugs over the past 15 years and have resulted in labeling of 10 new drugs by the United States Food and Drug Administration for treatment of hypertension in children and adolescents. Unfortunately the financial incentive structures focus on newer drugs and drug classes. Consequently there is now a relative dearth of trial data for older but sometimes commonly prescribed pediatric antihypertensive drugs. This article reviews recent pediatric antihypertensive drug trials with a focus on trial design and endpoints, drug dosing, safety, efficacy and specific drug indications. We also review the available data and experience for some of the more commonly prescribed, but less well studied “older” pediatric antihypertensive drugs.

Effects of nebivolol and atenolol on central aortic pressure in hypertensive patients: a multicenter, randomized, double-blind study

INTRODUCTION

The main objective was to compare the mean change in augmentation index of hypertensive patients treated with nebivolol or atenolol.

METHODS

Multicenter, double-blind randomized study conducted in six Spanish centers. We enrolled outpatients between the ages of 40 and 65 years with mild or moderate essential hypertension (systolic blood pressure, SBP ≥ 140 mmHg to ≤ 179 mmHg and diastolic blood pressure, DBP ≥ 90 mmHg to ≤ 109 mmHg after a 2-week run-in placebo period). Patients received nebivolol 5 mg or atenolol 50 mg once daily. At week 3, atenolol could be titrated up to 100 mg qd for non-responders. Additionally, patients not achieving normal blood pressure after 6 weeks could be treated with 25 mg hydrochlorothiazide. Follow-up visits were at 3, 6 and 10 weeks.

RESULTS

The final study population of 138 patients (58% men; median age 52.6 years, range 40-67 years) was randomized into two groups of 69 patients each. Baseline characteristics of the two groups were similar. At the screening visit, 69% presented with mild hypertension. Nebivolol modified the mean augmentation index to a lesser extent than atenolol after 10 weeks (mean difference 3.1%, 95% CI 0.55-5.69; p = 0.027). A higher proportion of patients in the atenolol group required a diuretic. Reductions in central aortic pressure and peripheral arterial pressure were similar for both treatment groups.

CONCLUSIONS

The study confirms that nebivolol produces a less pronounced impact on augmentation index than atenolol.

Efficacy of losartan and carvedilol on central hemodynamics in hypertensives: a prospective, randomized, open, blinded end point, multicenter study

Renin-angiotensin system (RAS) blockers have shown clinical outcomes superior to those of the beta (β)-blocker atenolol, despite similar reductions in the peripheral blood pressure (BP), perhaps because of different impacts on central hemodynamics. However, few comparative studies of RAS blockers and newer vasodilating β-blockers have been performed. We compared the central hemodynamic effects of losartan and carvedilol in a prospective, randomized, open, blinded end point study. Of the 201 hypertensive patients enrolled, 182 (49.6±9.9 years, losartan group=88 and carvedilol group=94) were analyzed. Carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), AIx corrected for a heart rate (HR) of 75 beats per minute (AIx@HR75) and central BP were measured noninvasively at baseline and after a 24-week treatment regimen with losartan or carvedilol. After 24 weeks, there were no between-group differences in the brachial BP, cfPWV, AIx@HR75 or central BP changes, except for a more favorable AIx effect with losartan. The changes in all measured metabolic and inflammatory parameters were also not significantly different between the two groups, except for uric acid. Losartan and carvedilol showed generally comparable effects on central hemodynamic indices, metabolic profile, inflammatory parameters and peripheral arterial pressure with a 24-week treatment.

Beta-blockers for hypertension

BACKGROUND

This review is an update of the Cochrane Review published in 2007, which assessed the role of beta-blockade as first-line therapy for hypertension.

OBJECTIVES

To quantify the effectiveness and safety of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

In December 2011 we searched the Cochrane Central Register of Controlled Trials, Medline, Embase, and reference lists of previous reviews; for eligible studies published since the previous search we conducted in May 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and combined them using the fixed-effects or random-effects method, as appropriate.

MAIN RESULTS

We included 13 RCTs which compared beta-blockers to placebo (4 trials, N=23,613), diuretics (5 trials, N=18,241), calcium-channel blockers (CCBs: 4 trials, N=44,825), and renin-angiotensin system (RAS) inhibitors (3 trials, N=10,828). Three-quarters of the 40,245 participants on beta-blockers used atenolol. Most studies had a high risk of bias; resulting from various limitations in study design, conduct, and data analysis.Total mortality was not significantly different between beta-blockers and placebo (RR 0.99, 95%CI 0.88 to 1.11; I(2)=0%), diuretics or RAS inhibitors, but was higher for beta-blockers compared to CCBs (RR 1.07, 95%CI 1.00 to 1.14; I(2)=2%). Total cardiovascular disease (CVD) was lower for beta-blockers compared to placebo (RR 0.88, 95%CI 0.79 to 0.97; I(2)=21%). This is primarily a reflection of the significant decrease in stroke (RR 0.80, 95%CI 0.66 to 0.96; I(2)=0%), since there was no significant difference in coronary heart disease (CHD) between beta-blockers and placebo. There was no significant difference in withdrawals from assigned treatment due to adverse events between beta-blockers and placebo (RR 1.12, 95%CI 0.82 to 1.54; I(2)=66%).The effect of beta-blockers on CVD was significantly worse than that of CCBs (RR 1.18, 95%CI 1.08-1.29; I(2)=0%), but was not different from that of diuretics or RAS inhibitors. In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95%CI 1.11-1.40; I(2)=0%) and RAS inhibitors (RR 1.30, 95%CI 1.11 to 1.53; I(2)=29%). However, CHD was not significantly different between beta-blockers and diuretics, CCBs or RAS inhibitors. Participants on beta-blockers were more likely to discontinue treatment due to adverse events than those on RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; I(2)=12%), but there was no significant difference with diuretics or CCBs.

AUTHORS' CONCLUSIONS

Initiating treatment of hypertension with beta-blockers leads to modest reductions in cardiovascular disease and no significant effects on mortality. These effects of beta-blockers are inferior to those of other antihypertensive drugs. The GRADE quality of this evidence is low, implying that the true effect of beta-blockers may be substantially different from the estimate of effects found in this review. Further research should be of high quality and should explore whether there are differences between different sub-types of beta-blockers or whether beta-blockers have differential effects on younger and elderly patients.

Beta-blockers for hypertension

BACKGROUND

This review is an update of the Cochrane Review published in 2007, which assessed the role of beta-blockade as first-line therapy for hypertension.

OBJECTIVES

To quantify the effectiveness and safety of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

In December 2011 we searched the Cochrane Central Register of Controlled Trials, Medline, Embase, and reference lists of previous reviews; for eligible studies published since the previous search we conducted in May 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and combined them using the fixed-effects or random-effects method, as appropriate.

MAIN RESULTS

We included 13 RCTs which compared beta-blockers to placebo (4 trials, N=23,613), diuretics (5 trials, N=18,241), calcium-channel blockers (CCBs: 4 trials, N=44,825), and renin-angiotensin system (RAS) inhibitors (3 trials, N=10,828). Three-quarters of the 40,245 participants on beta-blockers used atenolol. Most studies had a high risk of bias; resulting from various limitations in study design, conduct, and data analysis.Total mortality was not significantly different between beta-blockers and placebo (RR 0.99, 95%CI 0.88 to 1.11; I(2)=0%), diuretics or RAS inhibitors, but was higher for beta-blockers compared to CCBs (RR 1.07, 95%CI 1.00 to 1.14; I(2)=2%). Total cardiovascular disease (CVD) was lower for beta-blockers compared to placebo (RR 0.88, 95%CI 0.79 to 0.97; I(2)=21%). This is primarily a reflection of the significant decrease in stroke (RR 0.80, 95%CI 0.66 to 0.96; I(2)=0%), since there was no significant difference in coronary heart disease (CHD) between beta-blockers and placebo. There was no significant difference in withdrawals from assigned treatment due to adverse events between beta-blockers and placebo (RR 1.12, 95%CI 0.82 to 1.54; I(2)=66%).The effect of beta-blockers on CVD was significantly worse than that of CCBs (RR 1.18, 95%CI 1.08-1.29; I(2)=0%), but was not different from that of diuretics or RAS inhibitors. In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95%CI 1.11-1.40; I(2)=0%) and RAS inhibitors (RR 1.30, 95%CI 1.11 to 1.53; I(2)=29%). However, CHD was not significantly different between beta-blockers and diuretics, CCBs or RAS inhibitors. Participants on beta-blockers were more likely to discontinue treatment due to adverse events than those on RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; I(2)=12%), but there was no significant difference with diuretics or CCBs.

AUTHORS' CONCLUSIONS

Initiating treatment of hypertension with beta-blockers leads to modest reductions in cardiovascular disease and no significant effects on mortality. These effects of beta-blockers are inferior to those of other antihypertensive drugs. The GRADE quality of this evidence is low, implying that the true effect of beta-blockers may be substantially different from the estimate of effects found in this review. Further research should be of high quality and should explore whether there are differences between different sub-types of beta-blockers or whether beta-blockers have differential effects on younger and elderly patients.