Adrenoceptors and Hypertension

Hypertension is a very prevalent condition associated with high mortality and morbidity, secondary to changes resulting in blood vessels and resultant end-organ damage. Haemodynamic changes, including an initial rise in cardiac output followed by an increase in total peripheral resistance, denote the early changes associated with borderline or stage 1 hypertension, especially in young men. Increased sodium reabsorption leading to kidney damage is another mechanism proposed as one of the initial triggers for essential hypertension. The underlying pathophysiological mechanisms include catecholamine-induced α1- and ß1-adrenoceptor stimulation, and renin-angiotensin-aldosterone system activation leading to endothelial dysfunction which is believed to lead to persistent blood pressure elevation.α1 blockers, α2 agonists, and ß blockers were among the first oral anti-hypertensives. They are no longer first-line therapy after outcome trials did not demonstrate any benefits over and above other agents, despite similar blood pressure reductions. Angiotensin-converting enzyme inhibitors (or angiotensin receptor blockers), calcium channel blockers, and thiazide-like diuretics are now considered the first line of therapy, although adrenoceptor agents still have a role as second- or third-line therapy. The chapter also highlights hypertension in specific medical conditions such as pregnancy, phaeochromocytoma, hyperthyroidism, portal hypertension, pulmonary arterial hypertension, and ocular hypertension, to provide an overview for clinicians and researchers interested in the role of adrenoceptors in the pathophysiology and management of hypertension.

Physicians' attitudes toward beta-blockers for the treatment of hypertension in Italy, Poland, and Turkey

Despite substantial progress in understanding the complex pathophysiology, hypertension remains a serious public health challenge affecting over 1.2 billion adults aged 30-79 years worldwide. Appropriate knowledge of the different pharmaceutical classes of antihypertensive agents and an understanding of the characteristics of individual molecules are essential to optimize clinical outcomes in patients with hypertension. We conducted a computer-assisted web interviewing (CAWI) quantitative survey in Italy, Poland, and Turkey to investigate physicians' prescriptions, knowledge, and perceptions of antihypertensive drugs with a focus on β-blockers, to assess antihypertensive usage patterns and the reasons underlying prescription choices. The survey findings show that β-blockers retain a pivotal role in the management of hypertension and are prescribed more often for patients with cardiovascular comorbidities than for patients with diabetic comorbidities. In all three countries, nebivolol is the only β-blocker among the ones analyzed which is consistently prescribed to 20% or more of patients and is overall the most prescribed one for the population with comorbid diabetes. In terms of specific β-blockers' features, this study revealed knowledge gaps that underline the need for educational activities focused on the differences among β-blockers, which are important in choosing the most suitable agent for individualized antihypertensive therapy.

Revisiting Beta-Blocker Therapy in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous disorder and tends to be predominant in elderly, female, and obese patients. HFpEF has been classified using various cut-offs of left ventricular ejection fraction in the published studies with a current cut-off of ≥50%. The evidence of beta-blocker therapy in HFpEF patients showed conflicting findings with variably reported efficacy. This review aims to examine the published studies on the use of beta blockers for the treatment of patients with HFpEF.

Nebivolol elicits a neuroprotective effect in the cuprizone model of multiple sclerosis in mice: emphasis on M1/M2 polarization and inhibition of NLRP3 inflammasome activation

BACKGROUND AND AIM

Multiple sclerosis (MS) is a demyelinating neurodegenerative inflammatory disease affecting mainly young adults. Microgliosis-derived neuroinflammation represents a key hallmark in MS pathology and progression. Nebivolol (Neb) demonstrated antioxidant, anti-inflammatory and neuroprotective properties in several brain pathologies. This study was conducted to investigate the potential neuroprotective effect of Neb in the cuprizone (Cup) model of MS.

METHODS

C57Bl/6 mice were fed 0.2% Cup mixed into rodent chow for 5 weeks. Neb (5 and 10 mg/kg/day) was administered by oral gavage during the last 2 weeks.

RESULTS

Neb prevented Cup-induced weight loss and motor deficits as evidenced by increased latency to fall in the rotarod test and enhanced locomotor activity as compared to Cup-intoxicated mice. Neb reversed Cup-induced demyelination as confirmed by Luxol fast blue staining and myelin basic protein western blotting. Administration of Neb modulated microglial activation status by suppressing M1 markers (Iba-1, CD86, iNOS, NO and TNF-α) and increasing M2 markers (Arg-1 and IL-10) as compared to Cup-fed mice. Furthermore, Neb hindered NLRP3/caspase-1/IL-18 inflammatory cascade and alleviated oxidative stress by reducing lipid peroxidation, as well as increasing catalase and superoxide dismutase activities.

CONCLUSION

These findings suggest the potential neuroprotective effect of Neb in the Cup-induced model of MS in mice, at least partially by virtue of shifting microglia towards M2 phenotype, mitigation of NLRP3 inflammasome activation and alleviation of oxidative stress.

Matrix Metalloproteinase-2 Inhibition in Acute Ischemia-Reperfusion Heart Injury-Cardioprotective Properties of Carvedilol

Matrix metalloproteinase 2 (MMP-2) is activated in hearts upon ischemia-reperfusion (IR) injury and cleaves sarcomeric proteins. It was shown that carvedilol and nebivolol reduced the activity of different MMPs. Hence, we hypothesized that they could reduce MMPs activation in myocytes, and therefore, protect against cardiac contractile dysfunction related with IR injury. Isolated rat hearts were subjected to either control aerobic perfusion or IR injury: 25 min of aerobic perfusion, followed by 20 min global, no-flow ischemia, and reperfusion for 30 min. The effects of carvedilol, nebivolol, or metoprolol were evaluated in hearts subjected to IR injury. Cardiac mechanical function and MMP-2 activity in the heart homogenates and coronary effluent were assessed along with troponin I content in the former. Only carvedilol improved the recovery of mechanical function at the end of reperfusion compared to IR injury hearts. IR injury induced the activation and release of MMP-2 into the coronary effluent during reperfusion. MMP-2 activity in the coronary effluent increased in the IR injury group and this was prevented by carvedilol. Troponin I levels decreased by 73% in IR hearts and this was abolished by carvedilol. Conclusions: These data suggest that the cardioprotective effect of carvedilol in myocardial IR injury may be mediated by inhibiting MMP-2 activation.

Management of pregnancy-related hypertensive disorders in patients infected with SARS CoV-2: pharmacological and clinical issues

Aims

Coronavirus-19 disease (COVID-19) continues to spread throughout the world. It is known that among patients with hypertension, diabetes, chronic respiratory disease, or cardiovascular diseases, COVID-19 is associated with greater morbidity and mortality compared with patients without these conditions. This correlation is of great importance in pregnant women affected by COVID-19, since it usually leads to the development of a serious clinical complication. In particular, managing hypertensive disorders in pregnancy can be problematic because antihypertensive medications may interact pharmacologically with drugs used to treat COVID-19. This review focuses on the safety of drug treatment for COVID-19 in pregnant women treated with antihypertensive medication.

Methods and results

Several databases were searched to identify relevant literature. A few antihypertensive drugs and antithrombotic treatments are known for having a beneficial effect in the management of hypertension and hypertensive disorders in pregnancy. In this review, we focus on the expected drug–drug interactions with the experimental agents most often used to treat COVID-19.

Conclusions

The current indications for the management of hypertension-related disorders in pregnancy maintain their validity, while the risk of pharmacological interaction with the currently tested anti-SARS-CoV-2 medications is relatively low.

Effect of β-blockers on the risk of COPD exacerbations according to indication of use: the Rotterdam Study

Observational studies report a reduction of COPD exacerbations in patients treated with β-blockers. In contrast, the Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease (BLOCK COPD) randomised controlled trial which excluded COPD patients with cardiovascular conditions showed an increase in COPD exacerbations. It is unclear whether this discrepancy could be explained by underlying cardiovascular comorbidity. We examined whether the association between use of β-blockers and risk of COPD exacerbations differed between patients with and without a cardiovascular indication for β-blockers use.

Within the Rotterdam Study, we followed COPD subjects until the first COPD exacerbation, or end of follow-up. Cardiovascular indication for β-blockers use was defined as a history of hypertension, coronary heart disease, atrial fibrillation and/or heart failure at baseline. The association between β-blockers use and COPD exacerbations was assessed using Cox proportional hazards models adjusted for age, sex, smoking, incident cardiovascular disease (i.e. heart failure, hypertension, atrial fibrillation and/or coronary heart disease during follow-up), respiratory drugs and nitrates.

In total, 1312 COPD patients with a mean age of 69.7±9.2 years were included. In patients with a cardiovascular indication (n=755, mean age of 70.4±8.8 years), current use of cardioselective β-blockers was significantly associated with a reduced risk of COPD exacerbations (HR 0.69, 95% CI 0.57–0.85). In contrast, in subjects without a cardiovascular indication (n=557, mean age of 68.8±9.7 years), current use of cardioselective β-blockers was not associated with an altered risk of COPD exacerbations (HR 0.94, 95% CI 0.55–1.62).

Use of cardioselective β-blockers reduced the risk of exacerbations in COPD patients with concomitant cardiovascular disease. Therefore, the potential benefits of β-blockers might be confined to COPD patients with cardiovascular disease.

Use of cardioselective β-blockers reduces the risk of COPD exacerbations in patients with concomitant cardiovascular disease. The potential benefits of β-blockers might be restricted to COPD patients with cardiovascular disease.https://bit.ly/3bB1RGg

The Potential Benefit of Beta-Blockers for the Management of COVID-19 Protocol Therapy-Induced QT Prolongation: A Literature Review

The World Health Organization (WHO) officially announced coronavirus disease 2019 (COVID-19) as a pandemic in March 2020. Unfortunately, there are still no approved drugs for either the treatment or the prevention of COVID-19. Many studies have focused on repurposing established antimalarial therapies, especially those that showed prior efficacy against Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV), such as chloroquine and hydroxychloroquine, against COVID-19 combined with azithromycin. These classes of drugs potentially induce prolongation of the QT interval, which might lead to lethal arrhythmia. Beta-blockers, as a β-adrenergic receptor (β-AR) antagonist, can prevent an increase in the sympathetic tone, which is the most important arrhythmia trigger. In this literature review, we aimed to find the effect of administering azithromycin, chloroquine, and hydroxychloroquine on cardiac rhythm disorders and our findings show that bisoprolol, as a cardio-selective beta-blocker, is effective for the management of the QT (i.e., the start of the Q wave to the end of the T wave) interval prolongation in COVID-19 patients.

Arterial hypertension in patients under antineoplastic therapy: a systematic review

BACKGROUND

Cardio-oncology aims to mitigate adverse cardiovascular manifestations in cancer survivors, but treatment-induced hypertension or aggravated hypertension has received less attention in these high cardiovascular risk patients.

METHODS

In this systematic review, we searched literature for contemporary data on the prevalence, pathophysiologic mechanisms, treatment implications and preventive strategies of hypertension in patients under antineoplastic therapy.

RESULTS

Several classes of antineoplastic drugs, including mainly vascular endothelial growth factor inhibitors, proteasome inhibitors, cisplatin derivatives, corticosteroids or radiation therapy were consistently associated with increased odds for new-onset hypertension or labile hypertensive status in previous controlled patients. Moreover, hypertension constitutes a major risk factor for chemotherapy-induced cardiotoxicity, which is the most serious cardiovascular adverse effect of antineoplastic therapy. Despite the heterogeneity of pooled studies, the pro-hypertensive profile of examined drug classes could be attributed to common structural and functional disorders. Importantly, certain antihypertensive drugs are considered to be more effective in the management of hypertension in this population and may partially attenuate indirect complications of cancer treatment, such as progressive development of cardiomyopathy and/or cardiovascular death. Nonpharmacological approaches to alleviate hypertension in cancer patients are also described, albeit adjudicated as less effective in general.

CONCLUSION

A growing body of evidence suggests that multiple antineoplastic agents increase the rate of progression of hypertension. Physicians need to balance the life-saving cancer treatment and the inflated risk of adverse cardiovascular events due to suboptimal management of hypertension in order to achieve improved clinical outcomes and sustained survival for their patients.

Nebivolol, But Not Metoprolol, Treatment Improves Endothelial Fibrinolytic Capacity in Adults With Elevated Blood Pressure

BACKGROUND

Vascular endothelial fibrinolytic function is impaired in adults with prehypertension and hypertension and plays a mechanistic role in the development of atherothrombotic events. The influence of β-blockers on endothelial fibrinolysis is unknown. This study compared the effects of chronic nebivolol and metoprolol treatment on endothelial tissue-type plasminogen activator (t-PA) release in adults with elevated blood pressure (BP).

METHODS AND RESULTS

Forty-four middle-aged adults (36% women) with elevated BP completed a 3-month, double-blind, randomized, placebo-controlled trial comparing nebivolol (5 mg/d), metoprolol succinate (100 mg/d), and placebo. Net endothelial t-PA release was determined in vivo in response to intrabrachial infusions of bradykinin and sodium nitroprusside before and after each intervention. In a subset, the dose-response curves to bradykinin and sodium nitroprusside were repeated with a coinfusion of the antioxidant vitamin C. At baseline, resting BP and endothelial t-PA release were comparable between the 3 groups. BP decreased to a similar extent (≈10 mm Hg) in the nebivolol- and metoprolol-treated groups. There was a substantial increase (≈30%; P<0.05) in the capacity of the endothelium to release t-PA following chronic treatment with nebivolol but not metoprolol or placebo. Mitigating oxidant stress with vitamin C coinfusion potentiated t-PA release (90%; P<0.05) at baseline in all groups. However, after the intervention, t-PA release was unchanged by vitamin C coinfusion in the nebivolol group only.

CONCLUSIONS

Nebivolol but not metoprolol improves endothelial t-PA release in adults with elevated BP. This may be an important vascular benefit of nebivolol.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01595516.

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.

Novel insight into the dangerous connection between diabetes and heart failure

Heart failure (HF) affects approximately 1-2 % of the adult population. Diabetes mellitus (DM) is one of the most frequent comorbidities in HF, portending a worse prognosis. DM is associated with an increased risk of artery disease, and consequently of post-ischemic HF, but it may also alter directly the myocardial structure and function. Insights into the pathophysiological mechanisms of diabetic cardiomyopathy have been provided by both experimental and clinical investigations. In recent years, it has emerged that the fibrotic process is a result of the convergence of multiple neurohormonal alterations in diabetic cardiomyopathy at the basis of disease progression and phenotype determination: HF with reduced or preserved ejection fraction. Therapies for HF and DM should demonstrate an improved prognosis and have a neutral effect on glucose homeostasis and the risk of HF development.

Beta-blockers in COPD: time for reappraisal

The combined effects on the heart of smoking and hypoxaemia may contribute to an increased cardiovascular burden in chronic obstructive pulmonary disease (COPD). The use of beta-blockers in COPD has been proposed because of their known cardioprotective effects as well as reducing heart rate and improving systolic function. Despite the proven cardiac benefits of beta-blockers post-myocardial infarction and in heart failure they remain underused due to concerns regarding potential bronchoconstriction, even with cardioselective drugs. Initiating treatment with beta-blockers requires dose titration and monitoring over a period of weeks, and beta-blockers may be less well tolerated in older patients with COPD who have other comorbidities. Medium-term prospective placebo-controlled safety studies in COPD are warranted to reassure prescribers regarding the pulmonary and cardiac tolerability of beta-blockers as well as evaluating their potential interaction with concomitant inhaled long-acting bronchodilator therapy. Several retrospective observational studies have shown impressive reductions in mortality and exacerbations conferred by beta-blockers in COPD. However, this requires confirmation from long-term prospective placebo-controlled randomised controlled trials. The real challenge is to establish whether beta-blockers confer benefits on mortality and exacerbations in all patients with COPD, including those with silent cardiovascular disease where the situation is less clear.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure

Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 μg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this β-blocker on endothelial vasodilation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

Ischemic preconditioning and atenolol on lung injury after intestinal ischemia and reperfusion in rats

The aim of this study was evaluate the beta blocker atenolol (AT) and ischemic preconditioning (IPC) strategies for tissue protection against systemic effects of intestinal ischemia (I) and reperfusion (R) injury. Forty-two rats were pretreated with AT (1.5 mg · kg(-1)), 0.9% saline solution (SS; 0.1 mL), or IPC and then subjected to prolonged occlusion of the superior mesenteric artery for 60 minutes leading to I followed or not by 120 minutes of R, according to the group. For IPC, 5 minutes of I prior to 10 minutes of R were established. After this process of I or I-R, the right lung of each animal was adequately prepared for staining with hematoxylin and eosin and subsequent histologic analysis for quantification of inflammatory infiltrate was done. The left lung was frozen and prepared for assessment of oxidative stress by the quantification of thiobarbituric acid-reactivity substances (TBARS). Histologic analysis showed an important inflammatory infiltrate in the I-R + SS (I-R + SS = 4.5), which was significantly (P < .05) reduced by IPC (I-R + IPC = 3.0) or AT (I-R + AT = 3.0). Likewise, the TBARS levels were decreased by both strategies (I-R + SS = 0.63; I-R + IPC = 0.23; I-R + AT = 0.38; P < .05). Our results showed that AT and IPC attenuate pulmonary lesions caused by intestinal I and R process.

Nebivolol for improving endothelial dysfunction, pulmonary vascular remodeling, and right heart function in pulmonary hypertension

BACKGROUND

Endothelial cell (EC) dysfunction plays a central role in the pathogenesis of pulmonary arterial hypertension (PAH), promoting vasoconstriction, smooth muscle proliferation, and inflammation.

OBJECTIVES

This study sought to test the hypothesis that nebivolol, a β1-antagonist and β2,3-agonist, may improve PAH and reverse the PAH-related phenotype of pulmonary ECs (P-EC).

METHODS

We compared the effects of nebivolol with metoprolol, a first-generation β1-selective β-blocker, on human cultured PAH and control P-EC proliferation, vasoactive and proinflammatory factor production, and crosstalk with PA smooth muscle cells. We assessed the effects of both β-blockers in precontracted PA rings. We also compared the effects of both β-blockers in experimental PAH.

RESULTS

PAH P-ECs overexpressed the proinflammatory mediators interleukin-6 and monocyte chemoattractant protein-1, fibroblast growth factor-2, and the potent vasoconstrictive agent endothelin-1 as compared with control cells. This pathological phenotype was corrected by nebivolol but not metoprolol in a dose-dependent fashion. We confirmed that PAH P-EC proliferate more than control cells and stimulate more PA smooth muscle cell mitosis, a growth abnormality that was normalized by nebivolol but not by metoprolol. Nebivolol but not metoprolol induced endothelium-dependent and nitric oxide-dependent relaxation of PA. Nebivolol was more potent than metoprolol in improving cardiac function, pulmonary vascular remodeling, and inflammation of rats with monocrotaline-induced pulmonary hypertension.

CONCLUSIONS

Nebivolol could be a promising option for the management of PAH, improving endothelial dysfunction, pulmonary vascular remodeling, and right heart function. Until clinical studies are undertaken, however, routine use of β-blockers in PAH cannot be recommended.

Beneficial effects of nebivolol in comparison with atenolol on safety and tolerability in essential hypertension

INTRODUCTION

Hypertension, "The silent killer" is a multifactorial disorder which is asymptomatic and if left untreated leads to lethal complications. Nebivolol is a third generation beta blocker with additional vasodilating property due to nitric oxide release.

AIM

The current study aims to assess efficacy and safety of Nebivolol and compare with Atenolol.

METHODS

This was prospective, double blind, comparative controlled clinical study. Total 90 patients were enrolled into study as per selection criteria. Patients were randomized to receive Atenolol and Nebivolol with 45 patients in each group for 12 weeks.

RESULTS AND CONCLUSION

The mean reduction diastolic blood pressure in Nebivolol and Atenolol group was 10.77±2.60 and 10.05±2.83 respectively. The number of patients with adverse effect events was higher in the Atenolol than in the Nebivolol group (36.84% of Atenolol Vs 12.82% of Nebivolol). Thus it can be concluded that, for the same antihypertensive effect, Nebivolol was better tolerated than Atenolol.

A pharmacokinetic drug interaction study between nebivolol and paroxetine in healthy volunteers

WHAT IS KNOWN AND OBJECTIVE

Nebivolol is a highly selective beta-blocker with additional vasodilator properties, widely used in the clinical practice for the treatment of hypertension and heart failure. Paroxetine is a second-generation antidepressant and a potent inhibitor of CYP2D6, the same isoenzyme involved in the metabolism of nebivolol. The objective of this study was to investigate the effect of multiple-dose paroxetine intake on the pharmacokinetics of nebivolol in healthy volunteers and its potential consequences upon nebivolol pharmacodynamics.

METHODS

The study included 23 healthy subjects and was designed as an open-label, single-centre, non-randomized, two-period clinical trial. During period 1 (reference), each volunteer received a single dose of 5 mg nebivolol, whereas during period 2 (test), each volunteer received a single dose of 5 mg nebivolol and 20 mg paroxetine, after a pretreatment regimen with paroxetine (20-40 mg/day for 6 days). The pharmacokinetic parameters of nebivolol and its active metabolite were analysed by non-compartmental modelling. The pharmacodynamic parameters (blood pressure and heart rate) were assessed at rest, after each nebivolol intake.

RESULTS AND DISCUSSION

Pretreatment with paroxetine increased the mean peak plasma concentrations (Cmax ) for unchanged nebivolol (1·78 ± 1·17 vs. 4·24 ± 1·67 ng/mL) and for its active metabolite (0·58 ± 0·21 vs. 0·79 ± 0·24 ng/mL) compared to nebivolol alone. The time (tmax ) to reach Cmax was 1·37 ± 0·88 (h) and 3·11 ± 1·76 (h) for the parent compound and its active metabolite after nebivolol administered alone and 3·96 ± 1·76 (h), respectively, 7·33 ± 7·84 (h) after pretreatment with paroxetine. Also, the total areas under the curve (AUC0-∞ ) were significantly increased from 17·26 ± 43·06 to 106·20 ± 65·56 h ng/mL for nebivolol unchanged and 13·03 ± 11·29 to 74·56 ± 88·77 h ng/mL for its hydroxylated metabolite, before and after paroxetine intake. All the pharmacokinetic parameters presented statistically significant differences when paroxetine was administered with nebivolol. Nonetheless, statistical analysis did not show a significant difference between the vital signs measured during the two periods.

WHAT IS NEW AND CONCLUSION

After pretreatment with paroxetine, the exposure to nebivolol was increased by 6·1-fold for the parent drug and 5·7-fold for the hydroxylated active metabolite. Paroxetine influenced nebivolol pharmacokinetics in healthy volunteers, but it did not have a significant effect on nebivolol pharmacodynamic parameters measured at rest, although the clinical relevance of this drug interaction needs further investigation.

Lung Disease and Hypertension

Chronic obstructive pulmonary disease (COPD) patients are at a high risk of developing cardiovascular diseases. Airflow limitation is a predictor of future risks of hypertension and cardiovascular events. COPD is now understood as a systemic inflammatory disease, with the focus on inflammation of the lungs. An association between inflammation and sympathetic overactivity has also been reported. In this article, we review the association between chronic lung disease and the risks of hypertension, cardiovascular morbidity, the underlying mechanisms, and the therapeutic approach to hypertension and cardiovascular diseases in patients with lung diseases.

The effect of nebivolol on internal mammary artery blood flow during coronary artery bypass graft surgery

Background:

During coronary artery bypass grafting (CABG), one of the most important complications related to the internal mammary artery (IMA) is perioperative spasm. Nebivolol causes endothelium-dependent vascular relaxation by increasing nitric oxide (NO) release and prevents endothelial dysfunction in long-term use. In our study, we measured the effect of a third generation beta blocker, nebivolol, on the flow dynamics of IMA grafts.

Methods:

We recruited 90 hypertensive patients undergoing isolated CABG operation, who were divided into three groups and each group included 30 patients: Group 1 patients were under antihypertensive treatment other than beta-blockers (angiontensin-converting enzyme [ACE] inhibitors, calcium channel blockers or diuretics; monotherapy or combination therapy), Group 2 received metoprolol (50 mg/day) and Group 3 received nebivolol (5 mg/day). These antihypertensive therapies were given for at least one week before the operation and continued thereafter. IMA blood flow volume was measured for one minute just before cardiopulmonary bypass (measurement A) and before left internal mammary artery (LIMA)-left anterior descending (LAD) artery anastomosis (measurement B) in the three groups. Cardiac output measurements were also achieved simultaneously.

Results:

The measurement A results were 56.3 ± 36.2, 54.6 ± 28.1 and 66.8 ± 34.2 mL/min in Groups 1, 2 and 3, respectively (p<0.05). The measurement B results were 78.3 ± 29.6, 80 ± 28.8 and 91.1 ± 40.8 mL/min in Groups 1, 2 and 3 (p<0.05), respectively. There were no differences in cardiac outputs among the groups; 5.2 ± 1.4, 5.0 ± 1.6 and 5.3 ± 1.1 L/min (p>0.05). While the cardiac outputs were similar within the three groups, the IMA free flow volume was higher in the nebivolol group after local papaverine use.

Conclusion:

Nebivolol might represent a good choice in hypertensive patients undergoing cardiac surgery by preventing perioperative myocardial hypoperfusion which increases early morbidity and mortality.

Protective effect of nebivolol on reserpine-induced neurobehavioral and biochemical alterations in rats

Reserpine-induced orofacial dyskinesia is a model that shares some mechanists' aspects with tardive dyskinesia whose pathophysiology has been related to oxidative stress. The present study was aimed to explore neuroprotective effects of nebivolol, an antihypertensive agent, on reserpine-induced neurobehavioral and biochemical alterations in rats. Reserpine (1mg/kg, s.c.) was used to induce neurotoxicity. Administration of reserpine for 3 days every other day significantly increased the vacuous chewing movements (VCMs), tongue protrusions (TPs) and reduced the locomotor activity in rats. Pre-treatment with nebivolol (5 and 10mg/kg, p.o. for 5 days) showed dose dependant decrease in VCMs and TP induced by reserpine. Nebivolol also showed significant improvement in locomotor activity. Reserpine significantly increased lipid peroxidation and reduced the levels of defensive antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH) in rat brain. Nebivolol reversed these effects of reserpine on oxidative stress indices; indicating amelioration of oxidative stress in rat brains. The results of the present study indicated that nebivolol has a protective role against reserpine-induced orofacial dyskinesia. Thus, the use of nebivolol as a therapeutic agent for the treatment of tardive dyskinesia may be considered.

Atenolol to treat intestinal ischemia and reperfusion in rats

To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with AT (1.5 mg · kg(-1), intravenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy analysis. Compared to the sham group, jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.

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.

Central hemodynamics in prehypertension: effect of the β-adrenergic antagonist nebivolol

The aim of the current study was to characterize the effects of the novel β-adrenergic antagonist nebivolol on central aortic blood pressures, arterial properties, and nitroxidergic activity in individuals with prehypertension. Prehypertension is emerging as a major risk factor for several adverse cardiovascular consequences. Increased pulse wave velocity, aortic augmentation index, and aortic blood pressures have been linked with augmented risk of cardiovascular disease and mortality. While the effects of antihypertensive drugs on these parameters in hypertensive patients have been studied, there are limited data so far in prehypertension. Fifty individuals with prehypertension were randomized to either nebivolol (5 mg per day) or placebo in a double-blind clinical trial. Patients underwent measurement of pulse wave velocity as well as aortic blood pressure and aortic augmentation index via pulse wave analysis at baseline and 8 weeks. Patients also had blood and urine biochemistries done at each visit. Nebivolol achieved significant reductions in central aortic systolic (P=.011), diastolic (P=.009), and mean arterial blood pressure (P=.002). Pulse wave velocity trended toward improvement but did not achieve significance (P=.088). Nitric oxide production, measured as urinary nitrite/nitrite excretion, also rose substantially in the nebivolol group (by approximately 60%, P=.030). Central blood pressures can be effectively lowered by β-blockade while patients are still in the prehypertension phase, and the effects may be coupled to improve nitric oxide release by the drug.

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.

Nebivolol-induced vasodilation of renal afferent arterioles involves β3-adrenergic receptor and nitric oxide synthase activation

Nebivolol is a β(1)-adrenergic blocker that also elicits renal vasodilation and increases the glomerular filtration rate (GFR). However, its direct actions on the renal microvasculature and vasodilator mechanism have not been established. We used the in vitro blood-perfused juxtamedullary nephron technique to determine the vasodilator effects of nebivolol and to test the hypothesis that nebivolol induces vasodilation of renal afferent arterioles via an nitric oxide synthase (NOS)/nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway and the afferent arteriolar vasodilation effect may be mediated through the release of NO by activation of NOS via a β(3)-adrenoceptor-dependent mechanism. Juxtamedullary nephrons were superfused with nebivolol either alone or combined with the sGC inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or the NOS inhibitor N(ω)-nitro-l-arginine (l-NNA) or the β-blockers metoprolol (β(1)), butoxamine (β(2)), and SR59230A (β(3)). Nebivolol (100 μmol/l) markedly increased afferent and efferent arteriolar diameters by 18.9 ± 3.0 and 15.8 ± 1.8%. Pretreatment with l-NNA (1,000 μmol/l) or ODQ (10 μmol/l) decreased afferent vasodilator diameters and prevented the vasodilator effects of nebivolol (2.0 ± 0.2 and 2.4 ± 0.6%). Metoprolol did not elicit significant changes in afferent vasodilator diameters and did not prevent the effects of nebivolol to vasodilate afferent arterioles. However, treatment with SR59230A, but not butoxamine, markedly attenuated the vasodilation responses to nebivolol. Using a monoclonal antibody to β(3)-receptors revealed predominant immunostaining on vascular and glomerular endothelial cells. These data indicate that nebivolol vasodilates both afferent and efferent arterioles and that the afferent vasodilator effect is via a mechanism that is independent of β(1)-receptors but is predominantly mediated via a NOS/NO/sGC/cGMP-dependent mechanisms initiated by activation of endothelial β(3)-receptors.

Effect of beta blocker therapy on survival of patients with heart failure and preserved systolic function following hospitalization with acute decompensated heart failure

BACKGROUND

The importance of heart failure with preserved ejection fraction is being increasingly recognized. However, there is a paucity of data about effective treatment for this condition. The present study investigated the impact of beta blocker therapy for 3 months before admission on the two-year survival of patients with heart failure and preserved systolic function hospitalized due to decompensated heart failure.

METHODS

We performed a retrospective cohort analysis of 345 consecutive patients with heart failure with preserved systolic function older than 18 years hospitalized due to decompensated heart failure. Two groups of patients were compared: those who received beta blockers within 3 months before admission (BB) and those who did not (NBB). The primary outcome was two year all cause mortality (maximal follow-up available in all subjects). To adjust for a potential misbalance between BB and NBB groups in baseline characteristics, a propensity score for beta blocker therapy was incorporated into the survival model.

RESULTS

154 patients (44.6%) received beta blockers prior to admission. Overall two year mortality rate in the BB group was 50% vs. 62.8% in the NBB group, log-rank test p = 0.016. Beta blockers showed protective effect on two-year survival after adjustment for comorbidities and propensity score (hazard ratio [HR], 0.69; 95% CI 0.47-0.99).

CONCLUSIONS

Therapy with beta blockers may have protective effect on survival of patients with heart failure with preserved systolic function.

Treatment strategies for chronic stable angina

INTRODUCTION

Stable angina pectoris - generally the expression of an imbalance between myocardial oxygen demand and supply - is often the first manifestation of ischemic heart disease. The effective management of this highly prevalent condition is largely dependent on the identification of the prevailing pathogenic mechanism, the implementation of lifestyle changes and the appropriate use of pharmacological agents and revascularization techniques. There is abundant literature on management of chronic stable angina, but publications are generally devoted to focused areas. There is a need for a comprehensive review that addresses both the different types of angina and their pathogenic mechanisms, as well as rational approaches to patient management.

AREAS COVERED

This paper reviews the pathogenesis and pathophysiological mechanisms of myocardial ischemia, along with its consequences and current treatment options. Relevant papers in the English literature were identified via PubMed, using the following keywords relating to chronic stable angina: ischemic heart disease, coronary artery disease and antianginal therapy.

EXPERT OPINION

The treatment of chronic stable angina has improved in recent years as a result of a better understanding of its pathogenic mechanisms, the implementation of lifestyle changes and aggressive management of risk factors, as well as pharmacological advances and better revascularization techniques. Understanding the pathogenesis of the disease is important to identify effective treatment strategies. A careful clinical history, the implementation of appropriate diagnostic tests and a rational use of antianginal drugs and revascularization protocols often ensure the successful control of the patient's symptoms.

The anti-oxidant and anti-apoptotic effects of nebivolol and zofenopril in a model of cerebral ischemia/reperfusion in rats

The aim of this experiment was to investigate whether nebivolol and zofenopril have protective effects against oxidative damage and apoptosis induced by cerebral ischemia/reperfusion (I/R). There were seven groups of rats, with each containing eight rats. The groups were: the control group, I/R group, I/R plus zofenopril, I/R plus nebivolol, I/R plus nebivolol and zofenopril, zofenopril only and nebivolol only. Cerebral I/R was induced by clamping the bilateral common carotid artery and through hypotension. The rats were sacrificed 1h after ischemia, and histopathological and biochemical analyses were carried out on their brains. The total antioxidant capacity was evaluated by using an automated and colorimetric measurement method developed by Erel. I/R produced a significant increase in the levels of total oxidant status and malondialdehyde levels, the number of caspase-3 immunopositive cells and activities of prolidase and paraoxonase in brain when compared with the control group (p<0.05). A significant decrease in brain total antioxidant capacity and nitric oxide levels were found in I/R group when compared with the control group (p<0.05). Both nebivolol and zofenopril treatment prevented decreasing of the total antioxidant capacity and nitric oxide levels, produced by I/R in the brain (p<0.05). Both nebivolol and zofenopril treatment prevented the total oxidant status, malondialdehyde levels, activities of paraoxonase and prolidase from increasing in brains of rats exposed to I/R (p<0.05). In conclusion, both nebivolol and zofenopril protected rats from ischemia-induced brain injury. The protection may be due to the indirect prevention of oxidative stress and apoptosis.

Effects of the long-term administration of nebivolol on the clinical symptoms, exercise capacity, and left ventricular function of patients with diastolic dysfunction: results of the ELANDD study

AIMS

We hypothesized that nebivolol, a beta-blocker with nitric oxide-releasing properties, could favourably affect exercise capacity in patients with heart failure and preserved left ventricular ejection fraction (HFPEF).

METHODS AND RESULTS

A total of 116 subjects with HFPEF, in New York Heart Association (NYHA) functional class II-III, with left ventricular ejection fraction (LVEF) >45%, and with echo-Doppler signs of LV diastolic dysfunction, were randomized to 6 months treatment with nebivolol or placebo, following a double-blind, parallel group design. The primary endpoint of the study was the change in 6 min walk test distance (6MWTD) after 6 months. Nebivolol did not improve 6MWTD (from 420 ± 143 to 428 ± 141 m with nebivolol vs. from 412 ± 123 to 446 ± 119 m with placebo, P = 0.004 for interaction) compared with placebo, and the peak oxygen uptake also remained unchanged (peakVO(2); from 17.02 ± 4.79 to 16.32 ± 3.76 mL/kg/min with nebivolol vs. from 17.79 ± 5.96 to 18.59 ± 5.64 mL/kg/min with placebo, P = 0.63 for interaction). Resting and peak blood pressure and heart rate decreased with nebivolol. A significant correlation was found between the change in peak exercise heart rate and that in peakVO(2) (r = 0.391; P = 0.003) for the nebivolol group. Quality of life, assessed using the Minnesota Living with Heart Failure Questionnaire, and NYHA classification improved to a similar extent in both groups, whereas N-terminal pro brain natriuretic peptide (NT-pro BNP) plasma levels remained unchanged.

CONCLUSIONS

Compared with placebo, 6 months treatment with nebivolol did not improve exercise capacity in patients with HFPEF. Its negative chronotropic effect may have contributed to this result.

Comparison of nebivolol and atenolol on blood pressure, blood sugar, and lipid profile in patients of essential hypertension

Background:

Nebivolol is a third-generation β-blocker, with highest β₁ selectivity and nitric-oxide-derived vasodilatation. It also exhibits antiproliferative and antioxidant property that has beneficial metabolic profile compared to second-generation β blockers like atenolol. This study was planned to study the comparative effects of nebivolol and atenolol on metabolic parameters in patients with essential hypertension.

Materials and Methods:

A prospective, randomized, parallel, open-label clinical study was carried out on patients with essential hypertension. The patients were randomly assigned to receive tablet atenolol (Group A) and nebivolol (Group B) for a period of 24 weeks. Investigations were carried out at baseline and at the end of study period, that is, 24 weeks. Out of 69 patients, 60 completed the study and the data was analyzed using student's t-test. P < 0.05 was considered statistically significant.

Results:

Atenolol and nebivolol both showed significant (P < 0.001) antihypertensive action after 24 weeks. Mean blood sugar and lipid profile were found to be significantly (P < 0.001) elevated after 24 weeks of treatment with atenolol but not with nebivolol. Heart rate was significantly (P < 0.001) decreased in both groups at 24 weeks.

Conclusion:

In view of metabolic adverse effects of atenolol, nebivolol is the better choice whenever β-blockers have to be used in essential hypertension.

Effects of nebivolol or irbesartan in combination with hydrochlorothiazide on vascular functions in newly-diagnosed hypertensive patients: the NINFE (Nebivololo, Irbesartan Nella Funzione Endoteliale) study

BACKGROUND

Arterial hypertension affects endothelial function and arterial stiffness. The angiotensin (AT1) receptor antagonist irbesartan improves endothelial function and arterial stiffness in hypertensive patients. Nebivolol, a beta(1)-selective beta blocker, reduces systemic vascular resistance and stimulates nitric oxide release thus exerting positive effects on vascular function. However, comparative studies on the vascular effects of third generation beta-blockers and AT1 receptor blockers are lacking. Aim of this randomized, double-blind study was to test the hypothesis of non-inferiority of nebivolol to irbesartan, both in association with hydrochlorothiazide, on endothelial function, arterial stiffness and central hemodynamic parameters in patients with arterial hypertension naïve on therapy.

METHODS

Sixty-five patients were randomized to receive irbesartan/hydrochlorothiazide (150 mg/12.5 mg day) or nebivolol/hydrochlorothiazide (5mg/12.5 mg day) for 8-weeks. Endothelial function, pulse wave velocity, augmentation index, central and brachial blood pressures were measured at baseline and at the end of the study.

RESULTS

Systolic and diastolic central blood pressure, as well as brachial arterial pressure, decreased to a similar extent after both treatments. Similar changes in endothelial function between groups were detected at the end of the study. A significant reduction in pulse wave velocity, central blood pressure, and augmentation index adjusted for heart rate, was found in both the treatment groups at the end of the study, without significant differences between groups.

CONCLUSIONS

The results of this study confirm the hypothesis of non-inferiority of short-term treatment with nebivolol compared to irbesartan, both in association with hydrochlorothiazide, on endothelial function, arterial stiffness and central hemodynamic parameters in hypertensive patients naïve on therapy.

Modulating the nitric oxide - cyclic GMP pathway in the pressure-overloaded left ventricle and group II pulmonary hypertension

Group II pulmonary hypertension (PH) commonly occurs in the setting of a pressure-overloaded left ventricle (LV) which is also conducive to the development of heart failure with preserved ejection fraction. Population trends and a high prevalence of underlying causative conditions, such as essential hypertension or aortic stenosis, have increased the awareness of the pressure-overloaded LV and associated group II pulmonary hypertension. Patients often exhibit poor exercise tolerance and signs of heart failure indistinguishable from systolic heart failure; but effective medical treatments in this area have been lacking. Recent preclinical work has shed light on how the down-regulated nitric oxide - cyclic GMP pathway (within the myocardium and pulmonary vasculature) contributes to the pathophysiology of these associated conditions. This article will discuss the impact of the nitric oxide - cyclic GMP pathway on the pathogenesis of the pressure-overloaded LV and group II pulmonary hypertension, and will also introduce the potential therapeutic value of modulating this pathway.

Nitric oxide/reactive oxygen species generation and nitroso/redox imbalance in heart failure: from molecular mechanisms to therapeutic implications

Adaptation of the heart to intrinsic and external stress involves complex modifications at the molecular and cellular levels that lead to tissue remodeling, functional and metabolic alterations, and finally to failure depending upon the nature, intensity, and chronicity of the stress. Reactive oxygen species (ROS) have long been considered as merely harmful entities, but their role as second messengers has gradually emerged. At the same time, our comprehension of the multifaceted role of nitric oxide (NO) and the related reactive nitrogen species (RNS) has been upgraded. The tight interlay between ROS and RNS suggests that their imbalance may implicate the impairment in physiological NO/redox-based signaling that contributes to the failing of the cardiovascular system. This review initially provides basic concepts on the role of nitroso/oxidative stress in the pathophysiology of heart failure with a particular focus on sources of ROS/RNS, their downstream targets, and endogenous modulators. Then, the role of NO/redox regulation of cardiomyocyte function, including calcium homeostasis, electrogenesis, and insulin signaling pathways, is described. Finally, an overview of old and emerging therapeutic opportunities in heart failure is presented, focusing on modulation of NO/redox mechanisms and discussing benefits and limitations.

Lack of evidence that nebivolol is a β₃-adrenoceptor agonist

Nebivolol is a selective β₁-adrenoceptor antagonist which, in addition, displays endothelium-dependent vasodilating properties in humans and other species. β₃-adrenoceptors have been proposed to be a molecular target of nebivolol-induced vasodilatation. Therefore, we have investigated possible β₃-adrenoceptor agonism by nebivolol for relaxation of the human and rat urinary bladder (prototypical β₃-adrenoceptor-mediated responses) as well as for cAMP accumulation in Chinese hamster ovary cells stably transfected with the human β-adrenoceptor subtypes. Nebivolol concentration-dependently relaxed both human and rat isolated urinary bladder strips but with low potency, similar to that reported for vasodilatation. However, nebivolol-induced bladder relaxation in either species was not inhibited by the β₃-adrenoceptor antagonist SR 59,230A (10μM), although this compound inhibited the isoprenaline-induced relaxation with the expected potency. In radioligand binding studies nebivolol had lower affinity for human β₃-adrenoceptors than the other two β-adrenoceptor subtypes, but this low affinity was in line with its potency to relax the bladder or isolated blood vessels. In functional studies nebivolol even in high concentrations did not stimulate cAMP formation via any of the three cloned human β-adrenoceptors or in rat bladder smooth muscle cells. Taken together these data demonstrate that nebivolol can relax not only vascular but also urinary bladder smooth muscle. However, they do not support the hypothesis that nebivolol is an agonist at cloned human β₃-adrenoceptors or in rat or human urinary bladder.