How strong is the evidence for use of beta-blockers as first-line therapy for hypertension? Systematic review and meta-analysis

Autonomic control of ventricular function in health and disease: current state of the art

PURPOSE

Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.

METHODS

Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.

RESULTS

A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.

CONCLUSIONS

Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

A systematic review and meta-analysis of all sham and placebo controlled trials for resistant hypertension

INTRODUCTION

There is a lack of consensus regarding the best add on therapy for treatment of resistant hypertension (RH). This is likely secondary to a paucity of data on the comparative effectiveness of proposed therapies for RH.

METHODS

Placebo-controlled and sham-controlled randomized clinical trials testing therapies for the treatment of RH were included in this meta-analysis. Therapies with two or more studies were included as subgroups in this meta-analysis. The primary outcomes being tested were 24-hr systolic blood pressure (SBP) and office SBP.

RESULTS

Eight studies were identified that tested mineralocorticoid receptor antagonist (MRA) including 1,414 participants. The raw mean difference (RMD) between MRA and placebo control was statistically significant for 24-hour SBP (-10.56 mmHg; 95% confidence interval (CI) -12.82 to -8.30), 24-hour diastolic (DBP) (-5.48 mmHg; 95% CI -8.48 to -2.58), office SBP (-11.97 mmHg; 95% CI -16.41 to -7.54), and office DBP (-4.14 mmHg; 95% CI -5.62 to -2.65). Six studies were identified that tested renal denervation (RD) including 989 participants. The RMD between RD and sham control was not statistically significant for 24-hour SBP (-1.84 mmHg; 95% CI -3.92 to 0.24), 24-hour DBP (-0.66 mmHg; 95% CI -1.85 to 0.54), office SBP (-1.57 mmHg; 95% CI -6.04 to 2.89), and office DBP (-1.49 mmHg; 95% CI -3.52 to 0.55). Four studies were identified that tested endothelin receptor antagonists (ERA) including 1,193 participants. The raw mean difference (RMD) between ERA and placebo control was statistically significant for 24-hr systolic (SBP) (-7.02 mmHg; 95% CI -9.15 to -4.90, 24-hr diastolic (DBP) (-6.22 mmHg; 95% CI -7.61 to -4.82), office SBP (-5.84 mmHg; 95% CI -10.08 to -1.60), and office DBP (-3.73 mmHg; 95% CI -5.87 to -1.59).

DISCUSSION

MRA lowers BP in patients with RH more than RD, which seems to have little to no effect in RH. ERAs lead to a statistically significant reduction in BP but the confidence in efficacy is limited due to the low number of studies and differences in trial population. Individual factors and their impact on treatment response in RH should be investigated in future research.

Impact of beta blockers on resting respiratory rate in older adults: A cross-sectional study

[Purpose] Beta blockers, commonly prescribed for older adults, affect heart rates and blood pressure and may reduce respiratory rates, which are used to evaluate patient status and predict outcomes. However, limited clinical evidence is available on the impact of beta blockers on respiratory rates. This study aimed to investigate the impact of beta blockers on respiratory rates in older adults. [Methods] This cross-sectional study included patients aged ≥60 years who underwent an annual checkup. Patients were excluded if they had a diagnosis of severe heart failure, chronic obstructive pulmonary disease, interstitial pneumonitis, severe anemia, or neurodegenerative disease. Doubly robust estimation with inverse probability weighting was applied to estimate the mean differences between beta blocker users and non-users. The dose-response relationship between the administered beta blockers and respiratory rates was examined using multivariable regression models. [Results] Of 637 participants, 108 had received beta blockers regularly. The adjusted mean differences (95% confidence interval, CI) in respiratory rates, pulse rates, systolic blood pressure, and diastolic blood pressure between beta blocker users and non-users were 0.35 (-0.68 to 1.37), -3.56 (-6.34 to -0.78), -5.53 (-8.53 to -2.52), and -4.70 (-8.27 to -1.14), respectively. The adjusted mean differences (95% CI) in respiratory rates per 1 mg of a carvedilol equivalent dose in all beta blocker users, liposoluble beta blocker users, and carvedilol users were -0.10 (-0.18 to -0.02), -0.35 (-0.59 to -0.11), and -0.29 (-0.54 to -0.06), respectively. [Conclusions] Beta blockers may dose-dependently reduce the respiratory rates of older adults. However, in clinical settings, the impact of beta-blocker use or non-use on the respiratory rate may not occur at a clinically important level. Clinicians should note the potentially suppressive impact of beta blockers on respiratory rates according to the situation.

Can β-blockers influence regular daily physical activity?

BACKGROUND

In hypertension, β-blockers have a high rate of nonadherence to treatment likely because of fatigue.

METHODS

We evaluate daily physical activity and maximal exercise performance in 56 patients with hypertension (grades I-II), with and without β-blockers (bisoprolol 10 mg or atenolol 100 mg) added to standard treatment; 48 patients completed the study. Study tests were performed after 8 weeks of antihypertensive therapy without β blockers and after the following 8 weeks with β-blockers.

RESULTS

No significant differences between β-blockers were observed. At office measurement, β-blockers decreased heart rate (HR) from 78 ± 9 to 62 ± 7 bpm (P < 0.01) and SBP from 133 ± 13 to 125 ± 12 mmHg (P < 0.01). No significant changes were observed for DBP. Conversely, at ambulatory pressure monitoring DBP but not SBP decreased with β-blockers (mean-24-h DBP 77 ± 8 vs. 74 ± 7 mmHg, P < 0.01). An overall reduction of daily activities and of estimated kilocalories consumption was observed as measured by a portable armband device. Of note, time with activity more than 3 METS was reduced by β-blockers from 148.1 (83-201) to 117.9 (82-189) min (P < 0.01). Cardiopulmonary exercise (CPE) showed a preserved exercise performance unaffected by β-blockers.

CONCLUSION

In hypertension, β-blocker treatment is associated to reduction of daily physical activity but not of maximal exercise performance.

Impact of medication on blood transcriptome reveals off-target regulations of beta-blockers

Background

For many drugs, mechanisms of action with regard to desired effects and/or unwanted side effects are only incompletely understood. To investigate possible pleiotropic effects and respective molecular mechanisms, we describe here a catalogue of commonly used drugs and their impact on the blood transcriptome.

Methods and results

From a population-based cohort in Germany (LIFE-Adult), we collected genome-wide gene-expression data in whole blood using in Illumina HT12v4 micro-arrays (n = 3,378; 19,974 gene expression probes per individual). Expression profiles were correlated with the intake of active substances as assessed by participants’ medication. This resulted in a catalogue of fourteen substances that were identified as associated with differential gene expression for a total of 534 genes. As an independent replication cohort, an observational study of patients with suspected or confirmed stable coronary artery disease (CAD) or myocardial infarction (LIFE-Heart, n = 3,008, 19,966 gene expression probes per individual) was employed. Notably, we were able to replicate differential gene expression for three active substances affecting 80 genes in peripheral blood mononuclear cells (carvedilol: 25; prednisolone: 17; timolol: 38). Additionally, using gene ontology enrichment analysis, we demonstrated for timolol a significant enrichment in 23 pathways, 19 of them including either GPER1 or PDE4B. In the case of carvedilol, we showed that, beside genes with well-established association with hypertension (GPER1, PDE4B and TNFAIP3), the drug also affects genes that are only indirectly linked to hypertension due to their effects on artery walls or their role in lipid biosynthesis.

Conclusions

Our developed catalogue of blood gene expressions profiles affected by medication can be used to support both, drug repurposing and the identification of possible off-target effects.

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.

Benefits and adverse events of melatonin use in the elderly (Review)

Melatonin is a hormone secreted by the pineal gland in accordance with the circadian rhythm when the light level decreases. Reduction of melatonin secretion with age may be associated with physiological aging in neurodegenerative diseases by affecting the suprachiasmatic nucleus or of the neuronal pathways of transmission to the pineal gland. A significant decrease in melatonin synthesis has been reported in various disorders and diseases, including cardiovascular diseases, metabolic disorders (particularly diabetes type 2), cancer and endocrine diseases. In addition to the fact, that melatonin is a sleep inducer, it also exerts cytoprotective properties as an antioxidant and free radical scavenger. The therapeutic role of melatonin has been demonstrated in sleep disorders, eye damage and cardiovascular disease. The association between melatonin and β-blockers has had a positive impact on sleep disorders in clinical trials. Previous studies have reported the anti-inflammatory effect of melatonin by adjusting levels of pro-inflammatory cytokines, including interleukin (IL)-6, IL-1β and tumor necrosis factor-α. Melatonin treatment has been demonstrated to decrease IL-6 and IL-10 expression levels and efficiently attenuate T-cell proliferation. Currently, there is an inconsistency of scientific data regarding the lowest optimal dose and safety of melatonin for long-term use. The aim of the present review was to summarize the evidence on the role of melatonin in various clinical conditions and highlight the future research in this area.

Comprehensive Comparative Effectiveness and Safety of First-Line β-Blocker Monotherapy in Hypertensive Patients: A Large-Scale Multicenter Observational Study

[Figure: see text].

Age-Related Effect of Antihypertensive Treatment on Cognitive Performance: Is it Better Preventing Dementia in Older Age?

The aim of this study is to investigate the impact of optimal antihypertensive medication on cognitive function. In this 6-month clinical trial, 248 adults were randomly selected by a registry of hypertensive-treated patients (based on a National Hypertension Treatment Program), followed health centers located in Rafsanjan County, Southeast, Iran. Blood pressure was measured 3 times in each appointment pre- and posttreatment. Mini-Mental State Examination was used for cognitive performance evaluation. Paired t test and multiple regression model showed significant correlation between "the differences of systolic and diastolic blood pressure levels" and "cognitive performance in treated patients more than 40 years old." Cognitive performance was not significantly different in patients less than 40 years old post antihypertensive treatment. Cognitive performance scores demonstrated significant increase in responders more than 40 years old post antihypertensive treatment. Antihypertensive treatment in responders with age equal or more than 40 years improves the level of cognitive performance significantly.

Analysis of beta-blocker bioconcentration in brown planaria (Girardia dorotocephala) and its effects on regeneration

Production, distribution, and disposal of pharmaceutical products, including beta-blockers, have become a global issue. Beta-blockers are known to persist in the environment months after their release and may result in the disruption of the homeostatic system in non-target organisms. Here, we study the bioconcentration of three of the most commonly used beta-blockers and their effect on the regeneration of Girardia dorotocephala, a freshwater brown planarian. Acute toxicity tests determined LC₅₀s for acebutolol, metoprolol, and propranolol to be 778 mg/L, 711 mg/L, and 111 mg/L, respectively. The quantification and analysis of beta-blocker bioconcentration during acute exposure were performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). After 4 days of exposure to beta-blockers, the bioconcentration drastically decreased for all three beta-blockers at all exposure levels, suggesting that an effective mechanism to reduce uptake or excrete beta-blockers could be present. Additionally, Girardia dorotocephala were cut proximal to the head and the quality of regeneration was documented from each fragment daily. No significant difference was visually observed after 2 weeks of regeneration between the brown planarians placed in beta-blocker solution and those placed in control solution.

Effect of β-Blockers Beyond 3 Years After Acute Myocardial Infarction

Background

The optimal duration of β‐blocker therapy in patients with acute myocardial infarction (AMI) is unknown. We aimed to evaluate the late effect of β‐blockers in patients with AMI.

Methods and Results

We enrolled all consecutive patients who presented with AMI at Seoul National University Bundang Hospital, between June 3, 2003 and February 24, 2015. The primary end point was 5‐year all‐cause mortality, depending on the use of β‐blockers at discharge, 1 year after AMI, and 3 years after AMI. Of 2592 patients, the prescription rates of β‐blockers were 72%, 69%, 63%, and 60% at discharge and 1, 3, and 5 years after AMI, respectively. The patients who were receiving β‐blocker therapy had more favorable clinical characteristics, such as younger age (62 versus 65 years; P<0.001). They received reperfusion therapy more often (92% versus 80%; P<0.001) than those without β‐blocker prescription. In the univariate analysis, the patients with β‐blocker prescription had lower 5‐year mortality at all time points. In the Cox model after adjustment for significant covariates, β‐blocker prescription at discharge was associated with a 29% reduced mortality risk (hazard ratio, 0.71; 95% confidence interval, 0.55–0.90; P=0.006); however, β‐blocker prescriptions at 1 and 3 years after AMI were not associated with reduced mortality.

Conclusions

The beneficial effect of β‐blocker therapy after AMI may be limited until 1 year after AMI. Whether late β‐blocker therapy beyond 1 year after AMI offers clinical benefits should be confirmed in further clinical trials.

Mega clinical trials which have shaped the RAS intervention clinical practice

Following extensive clinical research, drugs affecting the renin-angiotensin system have been used for the treatment of patients with congestive heart failure, myocardial infarction, hypertension, diabetic nephropathy, chronic renal failure and for reducing the risk of developing major cardiovascular (CV) events. This review examines all mega trials (those involving >1000 patients) and smaller pivotal trials involving angiotensin-converting enzyme inhibitors (ACE-Is; 25 mega trials) and angiotensin receptor blockers (ARBs; 27 mega trials) to provide perspective on the huge database of evidence that has accumulated on the use of these drugs. Our review demonstrates that ACE-Is and ARBs are generally as effective as conventional therapies in the treatment of hypertension, but offer additional cardioprotective benefits in patients with heart failure, and in those who have experienced myocardial infarction. Also, both ACE-Is and ARBs are capable of renal protection in addition to their blood-pressure-lowering effects. Although ACE-Is and ARBs provide major benefits to CV patients, doubts remain over the concept of blood-pressure-independent CV protection offered by both classes of drugs. ACE-Is and ARBs appear to be equally effective with respect to morbidity and mortality endpoints, but ARBs are better tolerated. Considering the available evidence, the combined use of an ACE-I and ARB should be avoided and full doses of either ACE-I or ARB should be aimed for as evidence suggests they provide a greater prognostic benefit.

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.

Hypertension and Exercise Training: Evidence from Clinical Studies

Hypertension is a worldwide prevalent disease, mostly manifested as its primary ethiology, characterized by a chronic, multifactorial, asymptomatic, and usually incurable state. It is estimated that more than one billion of the world population is hypertensive. Also, hypertension is the main cause of the two most frequent causes of death worldwide: myocardial infarction and stroke. Due to the necessity of the cardiovascular system to manage chronically increased levels of blood pressure, hypertension causes severe alterations in multiple organs, as the heart, vessels, kidneys, eyes and brain, thus increasing the risk of health complications. The heart is the main target organ and suffers several adaptations to compensate the increased blood pressure levels; nevertheless, long-term adaptations without proper control are extremely harmful to cardiovascular health. On the other hand, hypertension is a modifiable risk factor and its adequate control is highly dependent on lifestyle. Pharmacological treatment is of great success when adherence is high. Several classes of antihypertensive drugs are prescribed and can effectively maintain blood pressure within acceptable levels. However, non-pharmacological methods, as diet and exercise training, can not only optimize the treatment but also prevent or postpone hypertension development as well as its complications, acting as important complements to the ideal control of elevated blood pressure, and bringing together benefits beyond blood pressure decrease, as a general health status improvement and increased quality of life. There is consistent evidence that regular exercise training promotes several benefits when properly prescribed and practised, acting as "medicine" for dozens of chronic diseases. The effects of exercise training in blood pressure levels and in its mechanisms of control are of clinical relevance and efficacy. This chapter will describe the classical and recent results on the beneficial effects of different modalities of exercise training in the cardiovascular system of human primary hypertension, focusing on the mechanisms influenced by exercise training which help to decrease blood pressure and improve the cardiovascular system.

Blood pressure control versus atrial fibrillation management in stroke prevention

Hypertension is one of the major risk factors for atrial fibrillation which in turn is the most prevalent concomitant condition in hypertensive patients. While both these pathological conditions are independent risk factors for stroke, the association of hypertension and atrial fibrillation increases the incidence of disabling strokes. Moreover, documented or silent atrial fibrillation doubles the rate of cardiovascular death. Lowering blood pressure is strongly recommended, particularly for primary stroke prevention. However, a relatively small percentage of hypertensive patients still achieve the recommended blood pressure goals. The management of atrial fibrillation with respect to stroke prevention is changing. New oral anticoagulants represent a major advancement in long-term anticoagulation therapy in non valvular atrial fibrillation. They have several benefits over warfarin, including improved adherence to the anticoagulation therapy. This is an important issue since non-adherence to stroke prevention medications is a risk factor for first and recurrent strokes.

Pathophysiological Mechanisms and Correlates of Therapeutic Pharmacological Interventions in Essential Arterial Hypertension

Treating arterial hypertension (HT) remains a hard task. The hypertensive patient is often a subject with several comorbidities and metabolic abnormalities. Clinicians everyday have to choose the right drug for the single patient among the different classes of antihypertensives. Apart from lowering blood pressure, a main therapeutic target should be that of counteracting all the possible pathophysiological mechanisms involved in HT itself and in existing/potential comorbidities. All the ancillary positive and negative effects of the administered drugs should be considered: in particular, since hypertensive patients are often glucose intolerant/diabetic, carrier of serum lipids disorder, have already developed atherosclerotic diseases and endothelial dysfunction, they should not be treated with drugs negatively interfering with these conditions but with molecules that, if possible, improve them. The main pathophysiological mechanisms and correlates of therapeutic pharmacological interventions in essential HT are reviewed here.

β-Blockers

Objective: To review the pharmacology, pharmacokinetics, and pharmacodynamic properties of commonly used β-blockers (atenolol, carvedilol, metoprolol succinate, metoprolol tartrate, and nebivolol). Data Sources: A MEDLINE literature search (1966-May 2013) was performed using the following key terms: hypertension, β-blockers, atenolol, carvedilol, metoprolol tartrate, metoprolol succinate, nebivolol, pharmacology, pharmacodynamics, pharmacokinetics, blood pressure, metabolic, lipid, central aortic pressure, diabetes, and insulin resistance. References from publications reviewed were included. Study Selection and Data Extraction: English-language articles identified were reviewed. Animal studies and studies in patients for a primary diagnosis of coronary artery disease were excluded. Data Synthesis: β-Blockers are no longer recommended first-line therapy for primary hypertension, based on data showing that β-blockers are inferior to other antihypertensives and no better than placebo, in spite of provision of blood pressure reduction. Because atenolol is the β-blocker used in 75% of these studies, uncertainty about widespread application to all β-blockers exists. Different pharmacological and physiological properties, both within β-blockers and compared with other antihypertensives, may explain divergent effects. Evidence shows that β-blockers have a truncated effect on central aortic pressure, an independent predictor of cardiovascular events, compared with other antihypertensive classes; differences within the class may exist, but the evidence is inconclusive. Metabolic effects differ within the β-blocker class, with evidence that carvedilol causes less metabolic dysregulation. Conclusion: Emerging evidence reveals physiological differences within the β-blocker class and in comparison to other antihypertensives. These differences provide insight into the diverse clinical effects β-blockers provide in cardiovascular disease.

Autonomic dysfunction in essential hypertension: A systematic review

Introduction

Greater sympathetic drive has been established in the early stages of essential hypertension, suggesting that neurohormonal dysregulation may be key to its aetiology and progression. The aims of this review are to discuss evidence of the role of autonomic dysfunction in essential hypertension and proposed mechanisms, and also some applications of this knowledge to current management strategies of essential hypertension.

Methods

A computer search was performed using the PUBMED database for peer reviewed original articles comparing autonomic function tested via heart rate variability (HRV), muscle sympathetic nerve activity (MSNA) or plasma noradrenaline levels in normotensive (mean blood pressure (BP) of ≤140/90 mmHg or ≤135/85 mmHg if measured via home BP measurements) and hypertensive groups (mean resting BP of ≥140/90 mmHg (or ≥135/85 mmHg if measured via home BP measurements). Subjects were excluded with secondary causes of hypertension or autonomic dysfunction.

Results

A total of 17 studies were included for discussion. The main findings of this study include that of reduced baroreflex sensitivity, believed to be secondary to increased arterial stiffness, is hypothesised to be implicated in the pathogenesis of essential hypertension. Also, angiotensin converting enzyme inhibitors were not as effective on markers of autonomic control of blood pressure when compared with alternative anti-hypertensive drugs.

Conclusions

Consistent research is needed to establish the effectiveness of pharmacotherapies at each of stage of hypertension, and on markers of autonomic dysfunction. Consistent study designs will enable more accurate accumulation of data across multiple studies, and appropriate application of such data into clinical practice.

A randomized controlled study on the effects of bisoprolol and atenolol on sympathetic nervous activity and central aortic pressure in patients with essential hypertension

Objective

β-blockers (BBs) with different pharmacological properties may have heterogeneous effects on sympathetic nervous activity (SNA) and central aortic pressure (CAP), which are independent cardiovascular factors for hypertension. Hence, we analyzed the effects of bisoprolol and atenolol on SNA and CAP in hypertensive patients.

Methods

This was a prospective, randomized, controlled study in 109 never-treated hypertensive subjects randomized to bisoprolol (5 mg) or atenolol (50 mg) for 4–8 weeks. SNA, baroreflex sensitivity (BRS) and heart rate (HR) variability (HRV) were measured using power spectral analysis using a Finometer. CAP and related parameters were determined using the SphygmoCor device (pulse wave analysis).

Results

Both drugs were similarly effective in reducing brachial BP. However, central systolic BP (−14±10 mm Hg vs −6±9 mm Hg; P<0.001) and aortic pulse pressure (−3±10 mm Hg vs +3±8 mm Hg; P<0.001) decreased more significantly with bisoprolol than with atenolol. The augmentation index at a HR of 75 bpm (AIxatHR75) was significantly decreased (29%±11% to 25%±12%; P = 0.026) in the bisoprolol group only. Furthermore, the change in BRS in the bisoprolol group (3.99±4.19 ms/mmHg) was higher than in the atenolol group (2.66±3.78 ms/mmHg), although not statistically significant (P>0.05). BRS was stable when RHR was controlled (RHR≤65 bpm), and the two treatments had similar effects on the low frequency/high frequency (HF) ratio and on HF.

Conclusion

BBs seem to have different effects on arterial distensibility and compliance in hypertensive subjects. Compared with atenolol, bisoprolol may have a better effect on CAP.

Trial Registration

ClinicalTrials.gov NCT01762436

Active ambulatory care management supported by short message services and mobile phone technology in patients with arterial hypertension

The use of short message services and mobile phone technology for ambulatory care management is the most accessible and most inexpensive way to transition from traditional ambulatory care management to active ambulatory care management in patients with arterial hypertension (AH). The aim of this study was to compare the clinical efficacy of active ambulatory care management supported by short message services and mobile phone technology with traditional ambulatory care management in AH patients. The study included 97 hypertensive patients under active ambulatory care management and 102 patients under traditional ambulatory care management. Blood pressure levels, body mass, and smoking history of patients were analyzed in the study. The duration of study was 1 year. In the active ambulatory care management group, 36% of patients were withdrawn from the study within a year. At the end of the year, 77% of patients from the active care management group had achieved the goal blood pressure level. That was more than 5 times higher than that in the traditional ambulatory care management group (P < .001). The risk ratio of achieving and maintaining the goal blood pressure in patients of active care management group was 5.44, CI (3.2-9.9; P = .005). Implementation of active ambulatory care management supported by short message services and mobile phone improves the quality of ambulatory care of hypertensive patients.

'Inappropriate' sinus tachycardia: does the 100 beats per min cut-off matter?

Sinus tachycardia is commonly encountered in clinical practice and when persistent, can result in significant symptoms and impaired quality of life, warranting further evaluation. On the other hand, a growing body of epidemiological and clinical evidence has shown that high resting heart rate (HR) within the accepted normal range is independently associated with increased risk of all-cause and cardiovascular mortality. However, higher HR as a risk factor for adverse cardiovascular outcomes is frequently underappreciated. In this review, we focus on two challenging problems that span the spectrum of abnormally fast sinus HR. The first section reviews inappropriate sinus tachycardia, a complex disorder characterized by rapid sinus HR without a clear underlying cause, with particular emphasis on current management options. The latter section discusses the prognostic significance of elevated resting HR and reviews clinical evidence aimed at modifying this simple, yet highly important risk factor.

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.

The effect of antihypertensive drugs on chronic kidney disease: a comprehensive review

Data from randomized clinical trials and epidemiological evidence identify systemic hypertension as the second most common modifiable risk factor for chronic kidney disease (CKD) progression after diabetes mellitus. CKD may progress silently over the years and early diagnosis and control of hypertension is of major importance in delaying renal function decline. Recent guidelines for the treatment of hypertension suggest the use of a variety of antihypertensive drugs in order to achieve the desired blood pressure levels. Renin-angiotensin system inhibitors have been undoubtedly studied the most and are suggested by guidelines and experts as first choice in patients with hypertension and renal injury, particularly in those with diabetes, as they have repeatedly shown to significantly reduce proteinuria. Other classes of antihypertensive drugs have been studied to a lesser extent and they have their own unique properties and effects. However, it is now common knowledge that adequate blood pressure control is the most important factor for the preservation of renal function, so every drug that effectively lowers hypertension is believed to be renoprotective. The present article will review the latest data on the role and properties of each class of antihypertensive drugs on CKD.

Association of beta-blocker use with increased aortic wave reflection

Studies have found less cardiovascular risk reduction in patients treated with beta-blockers (BBs) compared with other agents. We compared the severity of aortic atherosclerosis, arterial stiffness, and wave reflection in patients treated and not treated with BBs. Seventy-two patients, 37 treated with BBs and 35 not treated, referred for transesophageal echocardiography were studied. Augmentation index (AI), heart-rate-corrected AI (AI-75), aortic systolic (SBP) and diastolic blood pressure, pulse wave velocity (PWV), and aortic intima-media thickness (MAIMT) were measured. There were no differences in MAIMT (2.8 +/- 1.6 mm vs. 2.4 +/- 1.2 mm, P = .20) and PWV (8.9 +/- 2.0 m/s vs. 8.5 +/- 2.6 m/s, P = .46) between the BB and non-BB groups. The BB group had higher AI (28.7 +/-11.9% vs. 22.3 +/- 14.1%, P = .04), AI-75 (27.7 +/- 10.7% vs. 20.1+/- 11.0%, P = .005), aortic SBP (140 +/- 21 mm Hg vs. 125 +/- 21 mm Hg, P = .01), and aortic pulse pressure (62 +/- 20 mm Hg vs. 47 +/- 19 mm Hg, P = .01) than the non-BB group despite similar brachial blood pressure. BB use was associated with increased aortic wave reflection despite similar degree of aortic atherosclerosis.

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.

Effects of beta-blocker use on volume status in hemodialysis patients

BACKGROUND

Removal and control of excess fluid with dialysis is considered critical for protection against cardiovascular sequelae. Antihypertensive agents including beta-blockers may influence hemodynamics, which may limit fluid removal during hemodialysis (HD).

METHODS

Fifty chronic HD patients underwent bioimpedance measurement before and after a midweek dialysis session. Data on volume status, blood pressure, antihypertensive medications, and bioimpedance were analyzed.

RESULTS

Patients in the high-volume status group used a significantly higher percentage of beta-blockers than patients in the low-volume status group (54.2 vs. 19.2%, respectively, p = 0.01). Multivariable regression revealed that the use of beta-blockers was independently positively associated with fluid overload (p < 0.05). Intradialytic muscle cramping occurred more often in the beta-blocker group than the control group (44.4 vs. 12.5%, respectively, p = 0.02).

CONCLUSIONS

Our results suggest that the use of beta-blockers was associated with fluid overload in HD patients, and patients being treated with them experienced more intradialytic muscle cramping during dialysis.

Trends in antihypertensives use among Moroccan patients

PURPOSE

In this study, we analyzed the consumption trends of antihypertensives in Morocco during the 1991-2010 period and the impacts after the institution of Mandatory Health Insurance and the marketing of generic drugs.

METHODS

We used sales data from the Moroccan subsidiary of IMS Health "Intercontinental Marketing Service". The consumption volumes were converted into defined daily doses (DDDs).

RESULTS

Between 1991 and 2010, outpatient consumption of antihypertensives went from 4.37 to 23.14 DDD/1000 inhabitants/day, a 5.30-fold increase. In 2010, calcium channel blockers (CCBs) and angiotensin converting enzyme inhibitors (ACEI) were the most consumed (4.97 DDD/1000 inhabitants/day) for each one, followed by diuretics (4.20 DDD/1000 inhabitants/day). The most consumed products were amlodipine (4.27 DDD/1000 inhabitants/day) followed by ramipril (3.18 DDD/1000 inhabitants /day) and indapamide (1.72 DDD/1000inhabitants/day). Between 1991 and 2010, the consumption of generic antihypertensives went from 2% to 46%.

CONCLUSION

Antihypertensive consumption increased between 1991 and 2010. However, despite the increase of generic drugs consumption, the levels of antihypertensive consumption remain lower than the needs of hypertensive patients.

Could NICE guidance on the choice of blood pressure lowering drugs be simplified?

Reecha Sofat and colleagues argue that prescribing advice needs updating in the light of recent evidence that all classes of blood pressure lowering drugs are broadly equivalent

Night-time exogenous melatonin administration may be a beneficial treatment for sleeping disorders in beta blocker patients

Sleep disorders are the common side effects of beta blockers. Beta blockers have been shown to reduce the production of melatonin via specific inhibition of adrenergic beta1-receptors. Exogenous melatonin, taken in the evening as a supplement, could reduce the central nervous system (CNS) side effects (sleep disorder) associated with beta-adrenergic receptor blockers as well as the potential risk associated with reduction of the melatonin synthesis.

Projected impact of polypill use among US adults: Medication use, cardiovascular risk reduction, and side effects

BACKGROUND

Polypills, which include multiple medications for reducing cardiovascular disease (CVD) risk in a single pill, have been proposed for population-wide use. The number of US adults eligible for polypills and potential benefits are unknown.

METHODS

The National Health and Nutrition Examination Survey 2003-2004 and 2007-2008 were analyzed to estimate treatment rates for medications proposed for inclusion in polypills (aspirin, statin, an angiotensin-converting enzyme [ACE] inhibitor, and a thiazide-type diuretic for those without and a β-blocker for those with a history of myocardial infarction) among US adults. The number of coronary heart disease (CHD) and stroke events potentially prevented through polypill use was projected by published meta-analyses and 3 large population-based cohort studies. Two polypill eligibility criteria were analyzed: (1) US adults ≥55 years and (2) US adults with a history of CVD.

RESULTS

There are 67.6 million US adults ≥55 years and 15.4 million US adults with a history of CVD and, thus, eligible for polypills using the 2 outlined criteria. In 2007 to 2008, 37.3% of US adults ≥55 years and 57.0% of those with a history of CVD were taking statins. Use of other polypill medications was also low. Polypill use by US adults aged ≥55 years is projected to potentially prevent 3.2 million CHD events and 1.7 million strokes over 10 years. Among those with a history of CVD, the potential to prevent of 0.9 million CHD events and 0.5 million strokes is projected.

CONCLUSIONS

Polypills have the potential to lower CVD incidence substantially among US adults.

Combination therapy in hypertension

The goal of antihypertensive therapy is to abolish the risks associated with blood pressure (BP) elevation without adversely affecting quality of life. Drug selection is based on efficacy in lowering BP and in reducing cardiovascular (CV) end points, including stroke, myocardial infarction, and heart failure. Although the choice of initial drug therapy exerts some effect on long-term outcomes, it is evident that BP reduction per se is the primary determinant of CV risk reduction. Available data suggest that at least 75% of patients will require combination therapy to achieve contemporary BP targets, and increasing emphasis is being placed on the practical tasks involved in consistently achieving and maintaining goal BP in clinical practice. It is within this context that the American Society of Hypertension presents this Position Paper on Combination Therapy for Hypertension. It will address the scientific basis of combination therapy, present the pharmacologic rationale for choosing specific drug combinations, and review patient selection criteria for initial and secondary use. The advantages and disadvantages of single-pill (fixed) drug combinations and the implications of recent clinical trials involving specific combination strategies will also be discussed.