Prospective, randomized comparison of effect of long-term treatment with metoprolol or carvedilol on symptoms, exercise, ejection fraction, and oxidative stress in heart failure

Heart rate-lowering drugs and outcomes in hypertension and/or cardiovascular disease: a meta-analysis

BACKGROUND AND AIMS

The benefits of heart rate (HR)-lowering drug treatment in hypertension remain controversial. The effects of HR lowering on cardiovascular (CV) outcomes, mortality, and adverse events in patients with hypertension and/or CV disease were evaluated.

METHODS

PubMed, the Embase, and the Cochrane Library were searched for randomized trials comparing HR-lowering drugs with placebo or less intensive treatment. Risk ratios and 95% confidence intervals for eight outcomes were calculated (random-effects model). Subgroup analyses for a standard HR reduction were used to compare risk estimates in different HR groups or age strata (PROSPERO CRD42024540924).

RESULTS

The database included 74 HR-lowering treatment trials (n = 157 764 patients). The average HR reduction over 2.7 years was 8.2 b.p.m. (baseline/attained HR: 76.2/65.6 b.p.m.). HR-lowering reduced coronary heart disease by 16%, heart failure by 9%, CV mortality by 14%, and all-cause mortality by 13% but increased adverse event-driven discontinuations by 25%. Significant mortality reductions were noted in post-acute myocardial infarction and heart failure. No significant outcome changes were observed with HR reduction in hypertension without CV disease, while the entire hypertensive population experienced increased stroke and mortality. Threshold analysis revealed that the effect on outcomes was not different across cutoffs (from ≥80 b.p.m. to almost 70 b.p.m.), except for heart failure. Treatment outcome effects were not different across progressively lower targets (from ≥70 b.p.m. to <65 b.p.m.), except for permanent discontinuations, which showed an incremental trend.

CONCLUSIONS

The HR reduction benefits are context-dependent. Optimising outcomes while considering potential risks, targeting 65-70 b.p.m. for all HR thresholds above 70 b.p.m. seems reasonable.

The β3-Adrenergic Receptor: Structure, Physiopathology of Disease, and Emerging Therapeutic Potential

The discovery and characterization of the signal cascades of the β-adrenergic receptors have made it possible to effectively target the receptors for drug development. β-Adrenergic receptors are a class A rhodopsin type of G protein-coupled receptors (GPCRs) that are stimulated mainly by catecholamines and therefore mediate diverse effects of the parasympathetic nervous system in eliciting "fight or flight" type responses. They are detectable in several human tissues where they control a plethora of physiological processes and therefore contribute to the pathogenesis of several disease conditions. Given the relevance of the β-adrenergic receptor as a molecular target for many pathological conditions, this comprehensive review aims at providing an in-depth exploration of the recent advancements in β3-adrenergic receptor research. More importantly, we delve into the prospects of the β3-adrenergic receptor as a therapeutic target across a variety of clinical domains.

The Possible Effect of β-Blocker Use on the Circulating MMP-2/TIMP-2 System in Patients with Chronic Kidney Disease on Conservative Treatment

Background: The purpose of the study was to determine whether the use of β-adrenoceptor antagonists (β-blockers) can affect metalloproteinase 2 (MMP-2) and its tissue inhibitor (TIMP-2) in patients with chronic kidney disease (CKD) on conservative treatment. Methods: The circulating MMP-2/TIMP-2 system, proinflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), and the marker of oxidative stress-Cu/Zn superoxide dismutase (Cu/Zn SOD)-were measured in 23 CKD patients treated with β-blockers [β-blockers (+)] and in 27 CKD patients not receiving the above medication [β-blockers (-)]. Results: The levels of MMP-2, TIMP-2, and IL-6 were significantly lower in the β-blockers (+) than in the β-blockers (-) group, whereas Cu/Zn SOD concentrations were not affected by β-blocker use. There was a strong, independent association between MMP-2 and TIMP-2 in both analyzed patient groups. In the β-blockers (+) group, MMP-2 levels were indirectly related to the signs of inflammation, whereas in the β-blockers (-) group, the alterations in the MMP-2/TIMP-2 system were associated with the oxidative stress marker and CKD etiology. Conclusions: This study is the first to suggest that the use of β-blockers was associated with the reduction in IL-6 and the MMP-2/TIMP-2 system in CKD, providing a pharmacological rationale for the use of β-blockers to reduce inflammation and abnormal vascular remodeling in CKD.

Hereditary hemochromatosis with homozygous C282Y HFE mutation: possible clinical model to assess effects of elevated reactive oxygen species on the development of cardiovascular disease

Hereditary hemochromatosis with the homozygous C282Y HFE mutation (HH-282H) is a genetic condition which causes iron overload (IO) and elevated reactive oxygen species (ROS) secondary to the IO. Interestingly, even after successful iron removal therapy, HH-282H subjects demonstrate chronically elevated ROS. Raised ROS are also associated with the development of multiple cardiovascular diseases and HH-282H subjects may be at risk to develop these complications. In this narrative review, we consider HH-282H subjects as a clinical model for assessing the contribution of elevated ROS to the development of cardiovascular diseases in subjects with fewer confounding clinical risk factors as compared to other disease conditions with high ROS. We identify HH-282H subjects as a potentially unique clinical model to assess the impact of chronically elevated ROS on the development of cardiovascular disease and to serve as a clinical model to detect effective interventions for anti-ROS therapy.

Medicine designed to combat diseases of affluence affects the early development of fish. How do plastic microparticles contribute?

The incidence of diseases of affluence, such as diabetes mellitus, cardiovascular diseases, high blood pressure, and high cholesterol has been reported to rise. Consequently, the concentrations of residues of drugs designed to treat these diseases have been rising in water bodies. Moreover, the toxicity of these pharmaceuticals towards fish and other non-target organisms can be even enhanced by microplastic particles that are reportedly present in surface water. Therefore, the aim of this study was to describe the effects of three highly prescribed drugs, in particular metoprolol, enalapril, and metformin on fish early-life stages. Also, it was hypothesized that polystyrene microparticles will increase the toxicity of metoprolol to fish early-life stages. Embryonal acute toxicity tests on Danio rerio and Cyprinus carpio were carried out in order to describe the possible toxic effects of metoprolol, enalapril, and metformin. Also, the acute toxicity of polystyrene microparticles and the combination of metoprolol with polystyrene microparticles were tested on D. rerio embryos. Additionally, a 31-day long embryo-larval subchronic toxicity test was carried out with C. carpio in order to describe the long-term effects of low concentrations of metoprolol. The results of the study show that both metoprolol and enalapril have the potential to disrupt the early development of the heart in the embryonal stages of fish. Also, enalapril and metformin together with polystyrene microparticles seem to possibly disrupt the reproduction cycle and act as endocrine disruptors. Both pure polystyrene microparticles and the combination of them with metoprolol affect inflammatory processes in organisms. Additionally, metformin alters several metabolism pathways in fish early-life stages. The results of the study bring new evidence that even low, environmentally-relevant concentrations of pharmaceuticals have the potential to disrupt the early development of fish, particularly on a molecular level.

The Impact of Pharmacotherapy for Heart Failure on Oxidative Stress-Role of New Drugs, Flozins

Heart failure (HF) is a multifactorial clinical syndrome involving many complex processes. The causes may be related to abnormal heart structure and/or function. Changes in the renin-angiotensin-aldosterone system, the sympathetic nervous system, and the natriuretic peptide system are important in the pathophysiology of HF. Dysregulation or overexpression of these processes leads to changes in cardiac preload and afterload, changes in the vascular system, peripheral vascular dysfunction and remodeling, and endothelial dysfunction. One of the important factors responsible for the development of heart failure at the cellular level is oxidative stress. This condition leads to deleterious cellular effects as increased levels of free radicals gradually disrupt the state of equilibrium, and, as a consequence, the internal antioxidant defense system is damaged. This review focuses on pharmacotherapy for chronic heart failure with regard to oxidation-reduction metabolism, with special attention paid to the latest group of drugs, SGLT2 inhibitors-an integral part of HF treatment. These drugs have been shown to have beneficial effects by protecting the antioxidant system at the cellular level.

Promising remedies for cardiovascular disease: Natural polyphenol ellagic acid and its metabolite urolithins

BACKGROUND

Cardiovascular disease (CVD) is a significant worldwide factor contributing to human fatality and morbidity. With the increase of incidence rates, it is of concern that there is a lack of current therapeutic alternatives because of multiple side effects. Ellagic acid (EA), the natural polyphenol (C14H6O8), is abundant in pomegranates, berries, and nuts. EA and its intestinal microflora metabolite, urolithins, have recently attracted much attention as a potential novel "medicine" because of their wide pharmacological properties.

PURPOSE

This study aimed to critically analyze available literature to summarize the beneficial effects of EA and urolithins, and highlights their druggability and therapeutic potential in various CVDs.

METHODS

We systematically studied research and review articles between 1984 and 2022 available on various databases to obtain the data on EA and urolithins with no language restriction. Their cardiovascular protective activities, underlying mechanism, and druggability were highlighted and discussed comprehensively.

RESULTS

We found that EA and urolithins may exert preventive and curative effects on CVD with negligible side effects and possibly regulate lipid metabolism imbalance, pro-inflammatory factor production, vascular smooth muscle cell proliferation, cardiomyocyte apoptosis, endothelial cell dysfunction, and Ca2+ intake and release. Potentially, this may lead to the prevention and amelioration of atherosclerosis, hypertension, myocardial infarction, cardiac fibrosis, cardiomyopathy, cardiac arrhythmias, and cardiotoxicities in vivo. Several molecules and signaling pathways are associated with their therapeutic actions, including phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, NF-κB, nuclear factor erythroid-2 related factor 2, sirtuin1, miRNA, and extracellular signal-regulated kinase 1/2.

CONCLUSION

In vitro and in vivo studies shows that EA and urolithins could be used as valid candidates for early prevention and effective therapeutic strategies for various CVDs.

Heart Failure and Drug Therapies: A Metabolic Review

Cardiovascular disease is the leading cause of mortality globally with at least 26 million people worldwide living with heart failure (HF). Metabolism has been an active area of investigation in the setting of HF since the heart demands a high rate of ATP turnover to maintain homeostasis. With the advent of -omic technologies, specifically metabolomics and lipidomics, HF pathologies have been better characterized with unbiased and holistic approaches. These techniques have identified novel pathways in our understanding of progression of HF and potential points of intervention. Furthermore, sodium-glucose transport protein 2 inhibitors, a drug that has changed the dogma of HF treatment, has one of the strongest types of evidence for a potential metabolic mechanism of action. This review will highlight cardiac metabolism in both the healthy and failing heart and then discuss the metabolic effects of heart failure drugs.

Efficacy of Add-on Therapy with Carvedilol and the Direct Renin Inhibitor Aliskiren for Improving Cardiac Sympathetic Nerve Activity, Cardiac Function, Symptoms, Exercise Capacity and Brain Natriuretic Peptide in Patients with Dilated Cardiomyopathy

Purpose/Method: Aliskiren is a direct renin inhibitor that has been reported to be effective for CHF, but the usefulness of combined therapy with carvedilol and aliskiren has not been reported. Forty-four patients with dilated cardiomyopathy (DCM) were randomized into a group receiving add-on therapy with carvedilol plus aliskiren and another group receiving carvedilol alone for 6 months. Nuclear imagings with ¹²³I-Metaiodobenzylguanidine (MIBG) and ^99mTc-Sestamibi were performed. Exercise capacity using a specific activity scale (SAS) and the New York Heart Association (NYHA) class were evaluated. Cardiac sympathetic nerve activity was evaluated by ¹²³I-MIBG imaging, with the delayed heart-to-mediastinum activity ratio (H/M), delayed total defect score (TDS), and washout rate (WR). Results: Combined add-on therapy with carvedilol and aliskiren improved several parameters much more than carvedilol alone (p<0.05) with respect to TDS, ejection fraction (EF), NYHA, SAS on 6 months and the changes in TDS, EF, end-diastolic volume and brain natriuretic peptide (BNP). Conclusion: Add-on therapy with carvedilol and aliskiren is more effective than carvedilol alone for improving cardiac sympathetic nerve activity, cardiac function, symptoms, exercise capacity, and brain natriuretic peptide in patients with DCM.

Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure

The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

The Influence of Menopause and Inflammation on Redox Status and Bone Mineral Density in Patients with Rheumatoid Arthritis

Although oxidative stress is considered to be one of the key pathogenic factors in rheumatoid arthritis (RA), there is insufficient knowledge regarding the impact of menopause on redox status in this population. Thus, this study is aimed at assessing the influence of menopause within healthy women and within RA patients as well as the impact of RA in premenopausal and postmenopausal women on redox status, with special reference to bone mineral density (BMD). A total of 90 women were included in the study, 42 with RA and 48 age-matched healthy controls. They were divided into subgroups according to the presence of menopause. Following oxidative stress parameters were measured spectrophotometrically: index of lipid peroxidation (measured as TBARS), nitrites (NO2 -), superoxide anion radical (O2 -), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). BMD was assessed by using a dual-energy X-ray absorptiometry scanner. Comorbidities and drug history were recorded. The levels of H2O2 and TBARS were elevated in patients with RA, while NO2 - and O2 - increased in healthy women, both in premenopausal and postmenopausal groups. SOD activity decreased in postmenopausal RA patients. BMD was reduced in postmenopausal RA women. There was a correlation between NO2 - and O2 - with Health Assessment Questionnaire (HAQ) index in RA patients. Given that postmenopausal state was associated with elevated oxidative stress within healthy women and that menopausal state did not affect redox homeostasis within RA patients, but the redox homeostasis was altered in both RA groups compared to healthy women, it can be presumed that impaired redox status in RA occurred due to presence of the disease, irrespective of age. Moreover, menopause attenuates BMD reduction in women with RA. These results may indicate the need for therapeutic use of antioxidants in the form of supplements in women with RA, regardless of age.

The Role of Oxidative Stress in Physiopathology and Pharmacological Treatment with Pro- and Antioxidant Properties in Chronic Diseases

Oxidative stress (OS) has the ability to damage different molecules and cellular structures, altering the correct function of organs and systems. OS accumulates in the body by endogenous and exogenous mechanisms. Increasing evidence points to the involvement of OS in the physiopathology of various chronic diseases that require prolonged periods of pharmacological treatment. Long-term treatments may contribute to changes in systemic OS. In this review, we discuss the involvement of OS in the pathological mechanisms of some chronic diseases, the pro- or antioxidant effects of their pharmacological treatments, and possible adjuvant antioxidant alternatives. Diseases such as high blood pressure, arteriosclerosis, and diabetes mellitus contribute to the increased risk of cardiovascular disease. Antihypertensive, lipid-lowering, and hypoglycemic treatments help reduce the risk with an additional antioxidant benefit. Treatment with methotrexate in autoimmune systemic inflammatory diseases, such as rheumatoid arthritis, has a dual role in stimulating the production of OS and producing mitochondrial dysfunction. However, it can also help indirectly decrease the systemic OS induced by inflammation. Medicaments used to treat neurodegenerative diseases tend to decrease the mechanisms related to the production of reactive oxygen species (ROS) and balance OS. On the other hand, immunosuppressive treatments used in cancer or human immunodeficiency virus infection increase the production of ROS, causing significant oxidative damage in different organs and systems without widely documented exogenous antioxidant administration alternatives.

G-Protein-Coupled Receptors in Heart Disease

GPCRs (G-protein [guanine nucleotide-binding protein]-coupled receptors) play a central physiological role in the regulation of cardiac function in both health and disease and thus represent one of the largest class of surface receptors targeted by drugs. Several antagonists of GPCRs, such as βARs (β-adrenergic receptors) and Ang II (angiotensin II) receptors, are now considered standard of therapy for a wide range of cardiovascular disease, such as hypertension, coronary artery disease, and heart failure. Although the mechanism of action for GPCRs was thought to be largely worked out in the 80s and 90s, recent discoveries have brought to the fore new and previously unappreciated mechanisms for GPCR activation and subsequent downstream signaling. In this review, we focus on GPCRs most relevant to the cardiovascular system and discuss traditional components of GPCR signaling and highlight evolving concepts in the field, such as ligand bias, β-arrestin-mediated signaling, and conformational heterogeneity.

Antioxidant properties of probucol released from mesoporous silica

Antioxidants play a vital role in scavenging reactive oxygen species (ROS) produced by the reduction of molecular oxygen from various cellular mechanisms. Under oxidative stress, an increase in the levels of ROS overwhelms the antioxidant response, causing oxidative damage to biological molecules, and leading to the development of various diseases. Drug compounds with potent antioxidant properties are typically poorly water soluble and highly hydrophobic. An extreme case is Probucol (PB), a potent antioxidant with reported water solubility of 5 ng/ml, and oral bioavailiability of <10%. In this study, PB was loaded in mesoporous silica at various drug loadings to understand the changes to the physical properties of the loaded drug, and it's in vitro drug release. Further in vitro studies were conducted in endothelial and microglia cell models to compare the free radical scavening efficiency of ascorbic acid, PB, and PB release from mesoporous silica particles. Out of the three different mesostructured particles studied, the maximum loading of PB was achieved for large pore mesoporous particles (SBA-15) at 50 wt% drug loading, before complete pore filling was observed. For all materials, loadings above complete pore filling resulted in the recrystallization of PB on the external surface. In vitro drug release measurements showed a rapid dissolution rate at low drug loadings compared to a bimodal release profile of amorphous and crystalline drug at higher drug loadings. PB loaded in mesoporous particle was shown to enhance the antioxidant response to extracellular ROS in the endothelial cell line model, and to intracellular ROS in the microglia cell model. Our results indicate that the antioxidant properties of PB can be significantly improved by using mesoporous silica as a delivery vehicle.

Effects of carvedilol vs bisoprolol on inflammation and oxidative stress in patients with chronic heart failure

BACKGROUND

Inflammation and oxidative stress play a role in the pathophysiology of chronic heart failure (CHF). Our previous clinical trial, the Bisoprolol Improvement Group for Chronic Heart Failure Treatment Study in Dokkyo Medical University (BRIGHT-D), reported that bisoprolol is superior to carvedilol for myocardial protection in patients with CHF, as demonstrated by high-sensitivity cardiac troponin T (hsTnT) reduction. The present study was a subanalysis of the BRIGHT-D study that focused on the effects of bisoprolol vs carvedilol on inflammation and oxidative stress in CHF patients.

METHODS

Of the 87 patients enrolled in the BRIGHT-D trial, the present study included 48 patients (26 in the bisoprolol group and 22 in the carvedilol group) who had baseline and follow-up measurements of derivatives of reactive oxygen metabolites (d-ROMs) as an index of oxidative stress.

RESULTS

High-sensitivity C-reactive protein (hsCRP), an inflammatory marker, decreased in both groups; however, the decrease in the bisoprolol group [3.35 ± 0.78 to 2.69 ± 0.44 log (ng/ml), p = 0.001] was more significant than that in the carvedilol group [3.38 ± 0.59 to 2.85 ± 0.76 log (ng/ml), p = 0.047]. The d-ROMs also decreased in both groups; however, the decrease in the bisoprolol group (401 ± 106 to 344 ± 82 U.CARR, p = 0.015) was less significant than that in the carvedilol group (382 ± 84 to 312 ± 76 U.CARR, p = 0.006]. In all 48 patients, the change in hsTnT was correlated with that in hsCRP (R = 0.467, p = 0.003).

CONCLUSIONS

Bisoprolol may be better than carvedilol for reducing inflammation, but carvedilol may be better than bisoprolol for reducing oxidative stress. Proper use of bisoprolol or carvedilol based on individual pathophysiology could be promising in patients with CHF.

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.

The Antioxidant Therapy: New Insights in the Treatment of Hypertension

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a key role in the regulation of the physiological and pathological signaling within the vasculature. In physiological conditions, a delicate balance between oxidants and antioxidants protects cells from the detrimental effects of ROS/RNS. Indeed, the imbalance between ROS/RNS production and antioxidant defense mechanisms leads to oxidative and nitrosative stress within the cell. These processes promote the vascular damage observed in chronic conditions, such as hypertension. The strong implication of ROS/RNS in the etiology of hypertension suggest that antioxidants could be effective in the treatment of this pathology. Indeed, in animal models of hypertension, the overexpression of antioxidants and the genetic modulation of oxidant systems have provided an encouraging proof of concept. Nevertheless, the translation of these strategies to human disease did not reach the expected success. This could be due to the complexity of this condition, whose etiology depends on multiple factors (smoking, diet, life styles, genetics, family history, comorbidities). Indeed, 95% of reported high blood pressure cases are deemed "essential hypertension," and at the molecular level, oxidative stress seems to be a common feature of hypertensive states. In this scenario, new therapies are emerging that could be useful to reduce oxidative stress in hypertension. It is now ascertained the role of Vitamin D deficiency in the development of essential hypertension and it has been shown that an appropriate high dose of Vitamin D significantly reduces blood pressure in hypertensive cohorts with vitamin D deficiency. Moreover, new drugs are emerging which have both antihypertensive action and antioxidant properties, such as celiprolol, carvedilol, nebivolol. Indeed, besides adrenergic desensitization, these kind of drugs are able to interfere with ROS/RNS generation and/or signaling, and are therefore considered promising therapeutics in the management of hypertension. In the present review we have dealt with the effectiveness of the antioxidant therapy in the management of hypertension. In particular, we discuss about Vitamin D and anti-hypertensive drugs with antioxidant properties.

Adrenergic regulation during acute hepatic infection with Entamoeba histolytica in the hamster: involvement of oxidative stress, Nrf2 and NF-KappaB

Oxidative stress and transcriptional pathways of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB) are critically involved in the etiopathology of amebic liver abscess (ALA). In this work, we studied the relationship between the adrenergic nervous system and ALA in the hamster. ALA was visible at 12 h of infection. While 6-hydroxidopamine (6-OHDA) decreased infection, propranolol (β-adrenergic blocker) treatment was associated with less extensive liver damage, and phentolamine treatment (α-adrenergic blocker) significantly reduced ALA compared to 6-OHDA and propranolol. Serum enzymatic activities of alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (γ-GTP) were increased at 12 h post-infection. Chemical denervation and α and β-adrenergic blockers decreased ALT to normal levels, while 6-OHDA and propranolol showed a trend to decrease γ-GTP but phentolamine significantly reduced γ-GTP. Amebic infection increased oxidized glutathione (GSSG) and decreased both reduced glutathione (GSH) and the GSH/GSSG ratio. Propranolol and 6-OHDA showed a tendency to decrease GSSG. However, GSH, GSSG and GSH/GSSG returned to normal levels with phentolamine. Furthermore, amebic infection increased pNF-κB and interleukin-1β (IL-1β), and showed a tendency to decrease hemoxigenase-1 (HO-1), but not Nrf2. Chemical denervation showed a trend to decrease pNF-κB and IL-1β, and neither Nrf2 nor HO-1 increased significantly. In addition, NF-κB and IL-1β were attenuated by propranolol and phentolamine treatments, although phentolamine showed significant overexpression of Nrf2 and HO-1. This suggests that the adrenergic system may be involved in oxidative stress and in modulation of the Nrf2 and NF-κB pathways during ALA development.

A Review of the External Validity of Clinical Trials with Beta-Blockers in Heart Failure

BACKGROUND

Beta-blockers (BBs) are the mainstay prognostic medication for all stages of chronic heart failure (CHF). There are many classes of BBs, each of which has varying levels of evidence to support its efficacy in CHF. However, most CHF patients have one or more comorbid conditions such as diabetes, renal impairment, and/or atrial fibrillation. Patient enrollment to randomized controlled trials (RCTs) often excludes those with certain comorbidities, particularly if the symptoms are severe. Consequently, the extent to which evidence drawn from RCTs is generalizable to CHF patients has not been well described. Clinical guidelines also underrepresent this point by providing generic advice for all patients. The aim of this review is to examine the evidence to support the use of BBs in CHF patients with common comorbid conditions.

METHODS

We searched MEDLINE, PubMed, and the reference lists of reviews for RCTs, post hoc analyses, systematic reviews, and meta-analyses that report on use of BBs in CHF along with patient demographics and comorbidities.

RESULTS

In total, 38 studies from 28 RCTs were identified, which provided data on six BBs against placebo or head to head with another BB agent in ischemic and nonischemic cardiomyopathies. Several studies explored BBs in older patients. Female patients and non-Caucasian race were underrepresented in trials. End points were cardiovascular hospitalization and mortality. Comorbid diabetes, renal impairment, or atrial fibrillation was detailed; however, no reference to disease spectrum or management goals as a focus could be seen in any of the studies. In this sense, enrollment may have limited more severe grades of these comorbidities.

CONCLUSIONS

RCTs provide authoritative information for a spectrum of CHF presentations that support guidelines. RCTs may provide inadequate information for more heterogeneous CHF patient cohorts. Greater Phase IV research may be needed to fill this gap and inform guidelines for a more global patient population.

Pharmacodynamics ofβ-Blockers in Heart Failure: Lessons from the Carvedilol Or Metoprolol European Trial

Heart failure is a growing public health problem in the United States, and the approach to the treatment of heart failure has undergone a radical transformation in the past decade. The use of β-blocker therapy in heart failure patients is now widely recommended, based on evidence from large-scale clinical trials demonstrating that bisoprolol, carvedilol, and extended-release metoprolol succinate significantly reduce morbidity and mortality in patients with heart failure. Although these agents appear to provide similar benefits, the question remains whether pharmacologic differences among them could translate to differences in clinical outcomes. The Carvedilol Or Metoprolol European Trial (COMET) compared nonselective blockade of the β1-/β2-/α1-adrenergic receptors with carvedilol versus selective β1-blockade with immediate-release metoprolol tartrate in patients with chronic heart failure. The trial found that carvedilol significantly reduced all-cause mortality compared with immediate-release metoprolol tartrate, although there were no differences in hospitalizations. Herein we review the pharmacokinetics and pharmacodynamics of metoprolol and carvedilol. In doing so, several issues regarding the design of COMET are identified that could alter the interpretation of the results of this trial. These include the choice of dose and dosage regimen of immediate-release metoprolol tartrate, a dosage form that has never been shown to reduce mortality in patients with heart failure. Additional studies are needed to fully understand whether there are any advantages of selective versus nonselective adrenergic blockade and whether there are any clinically meaningful differences in effectiveness between β-blockers with proven benefit in the management of chronic heart failure. The results of COMET demonstrate that all β-blockers and dosage forms are not interchangeable when prescribed for heart failure. Clinicians should choose only those agents (and dosage forms) that have been proven to reduce mortality in this patient population.

A sensitive electrochemical sensor for the determination of carvedilol based on a modified glassy carbon electrode with ordered mesoporous carbon

This work describes the incorporation of ordered mesoporous carbon (OMC) as a sensing material for carvedilol (CAR) detection on a glassy carbon electrode (GCE).

Sympathetic Nervous System Control of Carbon Tetrachloride-Induced Oxidative Stress in Liver through α-Adrenergic Signaling

In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS) in modulating the hepatic response to oxidative stress. Our aim was to investigate the role of the SNS in healthy and oxidatively stressed liver parenchyma. Mice treated with 6-hydroxydopamine hydrobromide were used to realize chemical sympathectomy. Carbon tetrachloride (CCl₄) injection was used to induce oxidative liver injury. Sympathectomized animals were protected from CCl₄ induced hepatic lipid peroxidation-mediated cytotoxicity and genotoxicity as assessed by 4-hydroxy-2-nonenal levels, morphological features of cell damage, and DNA oxidative damage. Furthermore, sympathectomy modulated hepatic inflammatory response induced by CCl₄-mediated lipid peroxidation. CCl₄ induced lipid peroxidation and hepatotoxicity were suppressed by administration of an α-adrenergic antagonist. We conclude that the SNS provides a permissive microenvironment for hepatic oxidative stress indicating the possibility that targeting the hepatic α-adrenergic signaling could be a viable strategy for improving outcomes in patients with acute hepatic injury.

Is carvedilol better than other beta-blockers for heart failure?

There is wide consensus about the benefits of beta-blockers in systolic heart failure. However, it is not clear if one specific beta-blocker is superior to the others. Some guidelines favor three “evidence-based” beta-blockers (carvedilol, bisoprolol and metoprolol) that have proved to decrease mortality. Carvedilol might have different physiological properties, commonly referred as pleiotropic effects, but the clinical meaning of them is not clear. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified four systematic reviews including eight pertinent randomized controlled trials. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded there is little or no difference in hospitalization risk between carvedilol and bisoprolol or metoprolol, but carvedilol might decrease mortality compared to metoprolol or bisoprolol. It is uncertain whether nebivolol can be an alternative because the certainty of the evidence is very low.

The use of medications in the secondary prevention of coronary artery disease in the Asian region

BACKGROUND

Cardiovascular diseases, to which coronary artery disease (CAD) is a significant contributor, are a leading cause of long-term morbidity and mortality worldwide. In the years ahead, it is estimated that approximately half of the world's cardiovascular burden will occur in the Asian region. Currently there is a large gap in secondary prevention, with unrealized health gains resulting from underuse of evidence-based medications, including beta-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), aspirin and other antiplatelet agents, and lipid-lowering drugs. Despite the almost universal recommendation for these drugs in unstable CAD, their under-prescription is well documented for patients with acute heart failure, non-obstructive CAD, and for secondary prevention of CAD.

OBJECTIVE

This article reviews the burden of CAD in Asian countries together with guidelines supporting evidence-based medication use from a secondary prevention perspective.

METHODS

The MEDLINE database was searched from 2000 to 2013, inclusive, for country-specific data related to CAD and supplemented with unpublished registry data.

RESULTS

In the post-discharge setting following hospital admission for acute coronary syndromes, medication prescription rates were low. Beta-blocker prescription rates ranged from 49% in China to 99% in Singapore, ACE-inhibitor/ARB prescription rates ranged from 28% in China to 96% in Singapore, and lipid-lowering therapy rates ranged from 47% in China to 97% in Singapore. Aspirin/antiplatelet drug prescription rates ranged from 86% in Indonesia to 99.5% in Singapore. Recommendations are provided to improve patient outcomes and reduce the disease burden in Asia.

CONCLUSIONS

Despite recommendations issued in international and national guidelines, use of CAD medications in Asia remains suboptimal. In the absence of clear contraindications, all patients with unstable CAD should receive these agents as secondary prevention. This averts the need to target drug use according to risk, with high-risk features paradoxically associated with under-prescribing of such drugs.

The switching role of β-adrenergic receptor signalling in cell survival or death decision of cardiomyocytes

How cell fate (survival or death) is determined and whether such determination depends on the strength of stimulation has remained unclear. In this study, we discover that the cell fate of cardiomyocytes switches from survival to death with the increase of β-adrenergic receptor (β-AR) stimulation. Mathematical simulations combined with biochemical experimentation of β-AR signalling pathways show that the gradual increment of isoproterenol (a non-selective β₁/β₂-AR agonist) induces the switching response of Bcl-2 expression from the initial increase followed by a decrease below its basal level. The ERK1/2 and ICER-mediated feed-forward loop is the hidden design principle underlying such cell fate switching characteristics. Moreover, we find that β1-blocker treatment increases the survival effect of β-AR stimuli through the regulation of Bcl-2 expression leading to the resistance to cell death, providing new insight into the mechanism of therapeutic effects. Our systems analysis further suggests a novel potential therapeutic strategy for heart disease.

The contribution of signal strength on cell fate decisions is often not reflected in signalling networks. By combining mathematical simulation and biochemical experiments in cultured adult cardiomyocytes, Shin et al. show that the concentration of a β-adrenergic receptor agonist affects the expression of Bcl-2, influencing the balance between cell survival and death.

Oxidative stress markers and C-reactive protein are related to severity of heart failure in patients with dilated cardiomyopathy

Background. The aim of study was to determine relationships between functional capacity (NYHA class), left ventricle ejection fraction (LVEF), hemodynamic parameters, and biomarkers of redox state and inflammation in patients with dilated cardiomyopathy (DCM). Methods. DCM patients (n = 109, aged 45.97 ± 10.82 years), NYHA class IIV, and LVEF 2.94 ± 7.1% were studied. Controls comprised age-matched healthy volunteers (n = 28). Echocardiography and right heart catheterization were performed. Serum activities of superoxide dismutase isoenzymes (MnSOD and CuZnSOD), concentrations of uric acid (UA), malondialdehyde (MDA), and C-reactive protein (hs-CRP) were measured. Results. MnSOD, UA, hs-CRP, and MDA were significantly higher in DCM patients compared to controls. Except MDA concentration, above parameters were higher in patients in III-IV NYHA class or with lower LVEF. hsCRP correlated with of MnSOD (P < 0.05) and CuZnSOD activity (P < 0.01). Both isoenzymes positively correlated with mPAP and pulmonary capillary wedge pressure (MnSOD, resp., P < 0.01 and P < 0.05 and CuZnSOD P < 0.05; P < 0.05). UA positively correlated with MnSOD (P < 0.05), mPAP (P < 0.05), and PVRI (P < 0.05). The negative correlation between LVEF and UA (P < 0.01) was detected. Conclusion. There are relationships among the severity of symptoms of heart failure, echocardiographic hemodynamic parameters, oxidative stress, and inflammatory activation. Increased MnSOD activity indicates the mitochondrial source of ROS in patients with advanced heart failure.

β1-Adrenergic blockers exert antioxidant effects, reduce matrix metalloproteinase activity, and improve renovascular hypertension-induced cardiac hypertrophy

Hypertension induces left-ventricular hypertrophy (LVH) by mechanisms involving oxidative stress and unbalanced cardiac matrix metalloproteinase (MMP) activity. We hypothesized that β1-adrenergic receptor blockers with antioxidant properties (nebivolol) could reverse hypertension-induced LVH more effectively than conventional β1-blockers (metoprolol) when used at doses that exert similar antihypertensive effects. Two-kidney one-clip (2K1C) hypertension was induced in male Wistar rats. Six weeks after surgery, hypertensive and sham rats were treated with nebivolol (10 mg kg(-1)day(-1)) or metoprolol (20 mg kg(-1)day(-1)) for 4 weeks. Systolic blood pressure was monitored weekly by tail-cuff plethysmography. LV structural changes and fibrosis were studied in hematoxylin/eosin- and picrosirius-stained sections, respectively. Cardiac MMP levels and activity were determined by in situ zymography, gel zymography, and immunofluorescence. Dihydroethidium and lucigenin-derived chemiluminescence assays were used to assess cardiac reactive oxygen species (ROS) production. Nitrotyrosine levels were determined in LV samples by immunohistochemistry and green fluorescence and were evaluated using the ImageJ software. Cardiac protein kinase B/Akt (AKT) phosphorylation state was assessed by Western blot. Both β-blockers exerted similar antihypertensive effects and attenuated hypertension-induced cardiac remodeling. Both drugs reduced myocyte hypertrophy and collagen deposition in 2K1C rats. These effects were associated with lower cardiac ROS and nitrotyrosine levels and attenuation of hypertension-induced increases in cardiac MMP-2 levels and in situ gelatinolytic activity after treatment with both β-blockers. Whereas hypertension increased AKT phosphorylation, no effects were found with β-blockers. In conclusion, we found evidence that two β1-blockers with different properties attenuate hypertension-induced LV hypertrophy and cardiac collagen deposition in association with significant cardiac antioxidant effects and MMP-2 downregulation, thus suggesting a critical role for β1-adrenergic receptors in mediating those effects. Nebivolol is not superior to metoprolol, at least with respect to their capacity to reverse hypertension-induced LVH.

Impact of endovascular therapy on oxidative stress in patients with peripheral artery disease

BACKGROUND

Atherosclerosis is believed to be caused by oxidative stress. Endovascular therapy (EVT) is effective for claudication of patients with peripheral artery disease (PAD). However, its effect on oxidative stress in PAD patients is unknown. Here, the impact of EVT on oxidative stress in PAD patients is investigated.

METHODS AND RESULTS

Twenty-five PAD patients (Rutherford stage II or III) who underwent EVT were enrolled. The levels of diacron-reactive oxygen metabolite (d-ROM; an oxidative stress marker), ankle-brachial index (ABI), and maximum walking distance at baseline and at 3 months after EVT were measured. As compared with baseline values, the maximum walking distance and ABI improved significantly after EVT (109.9±104.2 vs. 313.7±271.8m, P<0.0001; 0.61±0.15 vs. 0.91±0.13m, P<0.0001, respectively). The improved exercise capacity and arterial flow induced a significant decrease in d-ROM levels (from 472.8±64.8 to 390.2±46.7U.CARR; P<0.0001). The decrease in d-ROM levels after EVT was more prominent in PAD patients with a high baseline d-ROM level. The increased ABI (r=0.524, P=0.0007) and maximum walking distance (r=-0.416, P=0.039) after EVT were significantly correlated with the decreased d-ROM levels.

CONCLUSIONS

The improved exercise capacity and peripheral blood flow induced by EVT decreases oxidative stress in PAD patients.

Carvedilol: use in chronic heart failure

Carvedilol is a beta-adrenergic antagonist with vasodilatory properties (alpha1-antagonism), which has been extensively evaluated in the treatment of patients with heart failure. In patients with chronic heart failure carvedilol improves left-ventricular (LV) ejection fraction over 6 to 12 months of treatment, and attenuates LV remodelling. Large-scale randomised, placebo controlled trials involving more than 4000 patients with chronic heart failure have demonstrated that carvedilol improves survival and reduces hospitalizations. Comparative studies with metoprolol in patients with heart failure have suggested that carvedilol may be associated with greater survival benefit although differences in the preparation of metoprolol have left uncertainty in this area. Carvedilol has a high safety profile and the clinical benefits appear maintained across a wide range of patients with comorbidities such as diabetes and renal failure. Carvedilol has also been shown to attenuate LV remodeling and improve clinical outcomes in patients with LV dysfunction and/or heart failure following acute myocardial infarction. As a result of these data, carvedilol is recommended for treatment of patients with heart failure in heart-failure guidelines. This evidence-based treatment should be widely implemented to ensure that patients with heart failure receive appropriate medical therapy.

Circulating levels of linoleic acid and HDL-cholesterol are major determinants of 4-hydroxynonenal protein adducts in patients with heart failure

OBJECTIVE

Measurements of oxidative stress biomarkers in patients with heart failure (HF) have yielded controversial results. This study aimed at testing the hypothesis that circulating levels of the lipid peroxidation product 4-hydroxynonenal bound to thiol proteins (4HNE-P) are strongly associated with those of its potential precursors, namely n-6 polyunsaturated fatty acids (PUFA).

METHODS AND RESULTS

Circulating levels of 4HNE-P were evaluated by gas chromatography-mass spectrometry in 71 control subjects and 61 ambulatory symptomatic HF patients along with various other clinically- and biochemically-relevant parameters, including other oxidative stress markers, and total levels of fatty acids from all classes, which reflect both free and bound to cholesterol, phospholipids and triglycerides. All HF patients had severe systolic functional impairment despite receiving optimal evidence-based therapies. Compared to controls, HF patients displayed markedly lower circulating levels of HDL- and LDL-cholesterol, which are major PUFA carriers, as well as of PUFA of the n-6 series, specifically linoleic acid (LA; P=0.001). Circulating 4HNE-P in HF patients was similar to controls, albeit multiple regression analysis revealed that LA was the only factor that was significantly associated with circulating 4HNE-P in the entire population (R (2)=0.086; P=0.02). In HF patients only, 4HNE-P was even more strongly associated with LA (P=0.003) and HDL-cholesterol (p<0.0002). Our results demonstrate that 4HNE-P levels, expressed relative to HDL-cholesterol, increase as HDL-cholesterol plasma levels decrease in the HF group only.

CONCLUSION

Results from this study emphasize the importance of considering changes in lipids and lipoproteins in the interpretation of measurements of lipid peroxidation products. Further studies appear warranted to explore the possibility that HDL-cholesterol particles may be a carrier of 4HNE adducts.

Novel carvedilol analogues that suppress store-overload-induced Ca2+ release

Carvedilol is a uniquely effective drug for the treatment of cardiac arrhythmias in patients with heart failure. This activity is in part because of its ability to inhibit store-overload-induced calcium release (SOICR) through the RyR2 channel. We describe the synthesis, characterization, and bioassay of ca. 100 compounds based on the carvedilol motif to identify features that correlate with and optimize SOICR inhibition. A single-cell bioassay was employed on the basis of the RyR2-R4496C mutant HEK-293 cell line in which calcium release from the endoplasmic reticulum through the defective channel was measured. IC50 values for SOICR inhibition were thus obtained. The compounds investigated contained modifications to the three principal subunits of carvedilol, including the carbazole and catechol moieties, as well as the linker chain containing the β-amino alcohol functionality. The SAR results indicate that significant alterations are tolerated in each of the three subunits.

Meta-analysis of carvedilol versus beta 1 selective beta-blockers (atenolol, bisoprolol, metoprolol, and nebivolol)

Because carvedilol is a unique vasodilating β blocker (BB) exerting antioxidant activity and pleiotropic effects, it was theorized that it may confer more potent beneficial effects on cardiovascular mortality and morbidity in acute myocardial infarction (AMI) and heart failure (HF) settings. A systematic review and meta-analysis was performed of randomized, controlled, direct-comparison trials that included adults receiving atenolol, bisoprolol, metoprolol, nebivolol, or carvedilol to evaluate the effects of carvedilol compared to other BBs on mortality, cardiovascular events, and hospital readmissions in the setting of AMI or systolic HF. Compared to β(1)-selective BBs used in HF (8 trials, n = 4,563), carvedilol significantly reduced all-cause mortality (risk ratio 0.85, 95% confidence interval 0.78 to 0.93, p = 0.0006). In 3 trials of patients with AMI (n = 644), carvedilol significantly reduced all-cause mortality by 45% (fixed-effects model: risk ratio 0.55, 95% confidence interval 0.32 to 0.94, p = 0.03, random-effects model: risk ratio 0.56, 95% confidence interval 0.26 to 1.12, p = 0.10), with no reduction in non-fatal MI (risk ratio 0.61, 95% confidence interval 0.31 to 1.22, p = 0.16). In conclusion, carvedilol, as compared against atenolol, bisoprolol, metoprolol and nebivolol in randomized direct comparison trials, significantly reduced all-cause mortality in systolic HF patients. Additionally, carvedilol significantly reduced all-cause mortality compared with β(1)-selective BBs in AMI patients using the fixed-effects model but not using the random-effects model.

The pathological roles of environmental and redox stresses in cardiovascular diseases

Oxidative stress and inflammation are implicated in cardiovascular diseases such as atherosclerosis, reperfusion injury, hypertension, and heart failure. High levels of oxidative stress resulting from increased cardiac generation of reactive oxygen species (ROS) is thought to contribute to contractile and endothelial dysfunction, apoptosis and necrosis of myocytes, and extracellular matrix remodeling in the heart. ROS activate several transcription factors known as redox-regulated transcription factors, and these transcription factors play important roles in the pathophysiology of cardiovascular diseases. This review focuses on the pathological roles of environmental and redox stresses in cardiovascular diseases, especially severe cardiac dysfunction and the transition from compensated hypertrophy to heart failure. The aryl hydrocarbon receptor (AHR) and NF-E2 p45-related factor (Nrf2) are transcription factors involved in the regulation of drug-metabolizing enzymes. AHR has been studied as a receptor for environmental contaminants and as a mediator of chemical toxicity. However, other roles for AHR in cardiac and vascular development have recently been described. Moreover, Nrf2 protects against oxidative stress by increasing the transcription of genes, including those for several antioxidant enzymes. The roles of these transcription factors, AHR and Nrf2 in angiogenesis are also discussed in this review.

Mechanistic clues in the protective effect of ellagic acid against apoptosis and decreased mitochondrial respiratory enzyme activities in myocardial infarcted rats

Our previous study described the cardioprotective effects of ellagic acid in an isoproterenol-induced myocardial infarction model. In this study, we are reporting the mechanism of protective action of ellagic acid with respect to apoptosis and mitochondrial respiratory enzymes. Ellagic acid (7.5 and 15 mg/kg) was administered orally as a pretreatment for 10 days. Then, isoproterenol (100 mg/kg) was injected subcutaneously to rats at an interval of 24 h for 2 days. Myocardial infarction was quantified by planimetry. Apoptosis was measured by apoptotic gene expressions. The levels of mitochondrial respiratory enzymes were also measured. Isoproterenol-induced myocardial infarcted rats showed increased infarct size, a decrease in myocardial expression of the Bcl-2 gene and an increase in myocardial expression of the BAX gene. Fas ligand and caspases were markedly elevated along with compromised respiratory marker enzymes in isoproterenol-induced rats. Ellagic acid pretreatment reduced the infarct size, regulated apoptotic gene expressions and enhanced the activities of mitochondrial respiratory marker enzymes and cell viability, thereby protecting the myocardium against isoproterenol-induced myocardial infarction. The decreased infarct size associated with inhibited apoptosis and increased respiratory marker enzymes provide insight on the role of ellagic acid in antiapoptotic mechanism, and it may be the reason for its cardioprotective activity.

Carvedilol reduces the severity of atherosclerosis in apolipoprotein E-deficient mice via reducing superoxide production

It has been shown that oxidative stress may play an important role in the development of atherosclerosis, and carvedilol has the capacity of reducing oxidative stress. Accordingly, we assessed the hypothesis that carvedilol may reduce the severity of atherosclerosis in apolipoprotein E (apoE)-deficient mice in addition to its hemodynamic effects. Atherosclerosis was induced in apoE-deficient mice fed a high-fat diet containing 0.3% cholesterol. Mice were orally treated with propranolol (30 mg/kg/day), metoprolol (75 mg/kg/day) and carvedilol (10 mg/kg/day) over eight weeks (each group n = 7-9). Fatty streak plaque developed in apoE-deficient mice, and was suppressed in mice treated with all three drugs. The accumulation of macrophages and expression of CD4(+) and CD8(+) cells in the lesions were decreased by the treatment of the drugs, of which carvedilol was the most effective. In addition, carvedilol reduced superoxide production in aortic walls detected by ethidium staining. There were no significant changes in blood pressure among the study groups. The heart rates in the treated groups were decreased by 4%-12% compared with the control group, with carvedilol yielding the highest suppression of heart rate. The β-blocker treatment did not significantly modify the serum lipid profiles. Carvedilol may suppress atherosclerosis via reducing superoxide production, in addition to the hemodynamic modifications in this animal model.

Development and validation of dissolution method for carvedilol compression-coated tablets

The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1% sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1% SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.

Cystatin C levels are associated with the prognosis of systolic heart failure patients

BACKGROUND

Cystatin C, which has long been regarded as a biomarker that indicates kidney functions, has recently been recognized as an inflammatory marker in the human body.

AIM

To elucidate how cystatin C is related to the prognosis of systolic heart failure patients.

METHODS

Patients with systolic heart failure who were admitted to the fourth affiliated hospital of Harbin Medical University between January and April 2008 were enrolled in this study. Serum homocysteine, high-sensitivity C-reactive protein (hs-CRP) and cystatin C levels were determined and all the patients received an average of 2 years of follow-up for occurrence of death, heart transplantation or readmission with worsening heart failure.

RESULTS

Of 138 patients enrolled, those who experienced adverse outcomes (e.g. cardiac death, heart transplantation or progressive heart failure) (n = 21) had considerably higher mean levels of serum homocysteine (28.6 ± 13.4 vs 14.4 ± 6.3mg/L; P < 0.01), hs-CRP (17.5 ± 14.1 vs 6.4 ± 7.7 μmol/L; p < 0.01) and cystatin C (1.63 ± 0.81 vs 0.91 ± 0.27 mg/L; P < 0.01) than those without adverse outcomes (n = 117). Furthermore, the Cox proportional hazards model demonstrated that serum homocysteine, hs-CRP and cystatin C are all independent predictors of adverse outcomes.

CONCLUSIONS

Cystatin C, together with hs-CRP and homocysteine, is an independent risk factor that is important in the prognosis of patients with systolic heart failure.

Beta-Blockers and Oxidative Stress in Patients with Heart Failure

Oxidative stress has been implicated in the pathogenesis of heart failure. Reactive oxygen species (ROS) are produced in the failing myocardium, and ROS cause hypertrophy, apoptosis/cell death and intracellular Ca²⁺ overload in cardiac myocytes. ROS also cause damage to lipid cell membranes in the process of lipid peroxidation. In this process, several aldehydes, including 4-hydroxy-2-nonenal (HNE), are generated and the amount of HNE is increased in the human failing myocardium. HNE exacerbates the formation of ROS, especially H₂O₂ and ·OH, in cardiomyocytes and subsequently ROS cause intracellular Ca²⁺ overload. Treatment with beta-blockers such as metoprolol, carvedilol and bisoprolol reduces the levels of oxidative stress, together with amelioration of heart failure. This reduction could be caused by several possible mechanisms. First, the beta-blocking effect is important, because catecholamines such as isoproterenol and norepinephrine induce oxidative stress in the myocardium. Second, anti-ischemic effects and negative chronotropic effects are also important. Furthermore, direct antioxidative effects of carvedilol contribute to the reduction of oxidative stress. Carvedilol inhibited HNE-induced intracellular Ca²⁺ overload. Beta-blocker therapy is a useful antioxidative therapy in patients with heart failure.

Comparative long term effects of nebivolol and carvedilol in hypertensive heart failure patients

BACKGROUND

Beta-blockers improve left ventricular (LV) systolic function and prognosis in patients with chronic heart failure (CHF), but their different pleiotropic properties may influence their cardiovascular effects. This open-label study compared the effects of long-term treatment with nebivolol versus carvedilol on LV ejection fraction (LVEF), in hypertensive CHF patients. Secondary end points were to assess the effect of the 2 beta-blockers on exercise capacity and clinical outcome.

METHODS AND RESULTS

A total of 160 hypertensive CHF patients, with LVEF <40% and in New York Heart Association (NYHA) functional class I, II, or III, were randomly assigned to receive nebivolol or carvedilol for 24 months. At baseline and at the end of treatment, all patients underwent clinical evaluation, echocardiography, and 6-minute walking test. The target doses were 10 mg/d for nebivolol and 50 mg/d for carvedilol. Compared with baseline values, LVEF increased by a similar extent in the carvedilol (C) and nebivolol (N) groups (C from 36.1% (SD 1.5%) to 40.9% (SD 1.9%), P < .001; N from 34.1% (SD 1.8%) to 38.5% (SF 2.2%), P < .001). Heart rate and NYHA functional class decreased significantly in both groups, and the 6-minute walking distance increased (C from 420 m (SD 104 m) to 490 m (SD 115 m), P < .001; N from 421 m (SD 118 m) to 487 m (SD 138 m), P < .001). During 24 months, 21 carvedilol recipients (26%) and 18 nebivolol recipients (22%) had cardiac events, including 3 and 4 deaths, respectively.

CONCLUSION

In the long term, nebivolol and carvedilol appear to be similarly effective in the treatment of hypertensive patients with CHF.

The Role of Carvedilol in the Treatment of Dilated and Anthracyclines-Induced Cardiomyopathy

Although chronic sympathetic activation provides inotropic and chronotropic support to the failing heart, such activation may also have deleterious effects, including the direct cardiotoxic effects of catecholamines, activation of the renin-angiotensin-aldosterone system and an increase in myocardial oxygen demand. These observations indicate that β-blockade might be beneficial in the treatment of heart failure resulting from dilated cardiomyopathy or ischaemic heart disease. Carvedilol is a non-selective β-blocker acting on β1-, β2-, and α1-adrenoceptors. It possesses potent anti-oxidant and anti-apoptotic properties, along with neuroprotective, vasculoprotective, cardioprotective effects, and it has reduced overall mortality in patients with heart failure in controlled clinical trials. Its role in treating cardiomyopathy requires focus. The fact that anthracyclines are cardiotoxic seriously narrows their therapeutic index in cancer therapy. The cardiotoxic risk increases with the cumulative dose and may lead to congestive heart failure and dilated cardiomyopathy in adults and in children. This review focuses on recent research regarding the beneficial effects of carvedilol in the treatment of dilated cardiomyopathy and to revisit the available evidence on the cardioprotection of carvedilol when associated with anthracycline and to explain the mechanisms underlying the benefits of their co-administration.

β-blockers and their mortality benefits: underprescribed in heart failure and chronic obstructive pulmonary disease

This article discusses the most recent insights into the actions of β-blockers on the heart and lungs, highlighting that β-blockers should have a place in the treatment of patients with chronic obstructive pulmonary disease (COPD), especially in those with coexisting cardiovascular disease or arterial hypertension. Practical studies clearly show underutilization of β-blockers in patients with heart failure and COPD, which seems to be caused by an unnecessary fear for adverse effects on the lungs, and the ‘outdated’ adverse effects mentioned on instruction leaflets.

Clinical updates on carvedilol: a first choice beta-blocker in the treatment of cardiovascular diseases

IMPORTANCE OF THE FIELD

Carvedilol, a non-selective beta-blocker, has recently drawn attention because of its therapeutic benefits over other prescribed analogues for the treatment of cardiovascular diseases (CVDs).

AREAS COVERED IN THIS REVIEW

The present review attempts to present the clinical efficacy of carvedilol in comparison to other available beta-blockers. The literature search was carried out in three electronic databases (Unbound Medline, Pubmed and Sciencedirect) and internet search engines (Scirus and Google Scholar) without time constraints to ensure maximum literature coverage.

WHAT THE READER WILL GAIN

A relatively large number of comparative studies have revealed that carvedilol has advantage over traditional beta-blockers with respect to hemodynamic and metabolic effects, due to its unique non-selective alpha-/beta-adrenoceptor affinity. Such results indicate its safe and effective therapeutic application particularly in patients with complicated CVDs, even in pediatric and geriatric patients.

TAKE HOME MESSAGE

The therapeutic profile of carvedilol indicates its suitability for treatment of complicated CVDs than other non-selective beta-blockers. However, there is a limitation in terms of its dose due to its low bioavailability (approximately 25%). Therefore, there is still need for bioavailability enhancement and dose reduction to further improve the therapeutic efficacy of the drug.