Acute hemodynamic effects of moderate doses of nebivolol versus metoprolol in patients with systolic heart failure

Early nebivolol treatment is beneficial in myocardial infarction in rats partly through β3-adrenoceptor remodelling

It remains unknown whether β-blockers are useful and safe in acute myocardial infarction (MI). Owing to its pharmacological profile and vasodilating action, nebivolol (N) is useful in MI. The aim of the present study was to assess in rat whether early nebivolol treatment could be beneficial in MI. It remains unknown whether β-blockers are useful and safe in acute MI. On day (D) 0, male Sprague-Dawley rats underwent left coronary artery ligation (MI) or simple thoracotomy (SHAM). On D1 and D2, the rats were treated with either nebivolol (5 mg.kg^-1 .day^-1 , MI-N and Sham-N) or vehicle (V, MI-V and Sham-V). On D3, heart rate, left ventricle (LV) intrinsic contractility (PESmid) and arterial elastance were measured. Cardiac and aortic β-Adrenoceptor (AR) subtype mRNA were quantified using real time quantitative RT-qPCR. Catecholamine response was assessed on isolated heart and aortic rings with isoproterenol. PESmid was decreased in MI without worsening the decrease nebivolol. In LV, β₁ - and β₃ -AR mRNA were respectively decreased and increased in all MI. β₃ -AR mRNA increase was partly limited by nebivolol. Ex vivo, basal contractility was less decreased in MI-N than in MI-V. Isoproterenol response was only altered in MI-V. In MI aorta, Nebi prevented β₂ - and β₃ -AR mRNA increases. In addition, Acetylcholine-induced relaxation was lowered in MI-V but preserved with nebivolol. We demonstrated an early modulation of cardiovascular β₃ -AR transcription early MI. Despite its putative negative inotropic properties, nebivolol did not worsen cardiac function in basal conditions and preserved LV catecholamine response.

Hypertension treatment in the Asia-Pacific: the role of and treatment strategies with nebivolol

Hypertension is a common disease, and hypertensive patients are at increased risk of cardiovascular events. The prevalence and socioeconomic burden of hypertension in the Asia-Pacific region are predicted to increase in the coming decades. Effective blood pressure lowering reduces overall cardiovascular morbidity and mortality in patients, yet doubt has been raised regarding the use of (mainly older generation) β-blockers as initial therapy in hypertension. Consequently, several international treatment guidelines do not recommend β-blockers for the treatment of hypertension. However, in contrast to first-generation and second-generation β-blockers, the third-generation, vasodilating β-blocker nebivolol has a considerably better metabolic, haemodynamic and side effect profile. In addition to providing effective blood pressure control similar to other β-blockers and drugs from other antihypertensive classes, nebivolol exerts a dual mechanism for increasing the bioavailability of the naturally occurring vasodilator nitric oxide. The clinical benefits and significance of enhancing nitric oxide levels in hypertensive patients have been shown in direct comparisons of nebivolol with other β-blockers. While β-blockers generally provide comparable blood pressure reductions, only nebivolol demonstrated enhanced vasodilation and blood flow by increasing the expression of endothelial nitric oxide synthase and therefore increasing nitric oxide release from the endothelium. In contrast to other β-blockers, therefore, it has been suggested that nebivolol has beneficial effects in several hypertensive subgroups due to its vasodilating properties. Considering the existing data, it may be timely for treatment guidelines to recommend third-generation vasodilating β-blockers as a first-line option for the pharmacotherapy of hypertension.

Nebivolol versus Carvedilol or Metoprolol in Patients Presenting with Acute Myocardial Infarction Complicated by Left Ventricular Dysfunction

OBJECTIVE

The aim of this study was to evaluate the efficacy of nebivolol, carvedilol or metoprolol succinate on the outcome of patients presenting with acute myocardial infarction (AMI) complicated by left ventricular dysfunction.

SUBJECTS AND METHODS

Patients (n = 172, aged 28-87 years) with AMI and left ventricular ejection fraction ≤0.45 were randomized to the nebivolol (n = 55), carvedilol (n = 60) and metoprolol succinate (n = 57) groups. Baseline demographic and clinical characteristics and composite event rates of nonfatal MI, cardiovascular mortality, hospitalization due to unstable angina pectoris or heart failure, stroke or revascularization during the 12-month follow-up were compared among the groups using the x03C7;2 test, t test or log-rank test as appropriate.

RESULTS

Baseline demographic and clinical characteristics were similar in the three groups. The composite end point during follow-up was lower in the patients treated with nebivolol than those treated with metoprolol (14.5 vs. 31.5%; p = 0.03). However, event rates were similar between the patients treated with carvedilol and those treated with the metoprolol (20.3 vs. 31.5%, p > 0.05) and between the patients treated with nebivolol and carvedilol (14.5 vs. 20.3%, p > 0.05).

CONCLUSION

The patients treated with nebivolol experienced 12-month cardiovascular events at a lower rate than those treated with metoprolol succinate. However, event rates were similar between the carvedilol and the metoprolol succinate groups and between the nebivolol and the carvedilol groups.

A Review of Nebivolol Pharmacology and Clinical Evidence

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

Nebivolol, but not metoprolol, lowers blood pressure in nitric oxide-sensitive human hypertension

Nebivolol, unlike other selective β1-receptor blockers, induces vasodilation attributable to increased NO bioavailability. The relative contribution of this mechanism to the blood pressure (BP)-lowering effects of nebivolol is unclear because it is normally masked by baroreflex buffering. Autonomic failure provides a unique model of hypertension devoid of autonomic modulation but sensitive to the hypotensive effects of NO potentiation. We tested the hypothesis that nebivolol would decrease BP in these patients through a mechanism independent of β-blockade. We randomized 20 autonomic failure patients with supine hypertension (14 men; 69±2 years) to receive a single oral dose of placebo, nebivolol 5 mg, metoprolol 50 mg (negative control), and sildenafil 25 mg (positive control) on separate nights in a double-blind, crossover study. Supine BP was monitored every 2 hours from 8:00 pm to 8:00 am. Compared with placebo, sildenafil and nebivolol decreased systolic BP during the night (P<0.001 and P=0.036, by mixed-effects model, maximal systolic BP reduction 8-hour postdrug of -20±6 and -24±9 mm Hg, respectively), whereas metoprolol had no effect. In a subanalysis, we divided patients into sildenafil responders (BP fall>20 mm Hg at 4:00 am) and nonresponders. Nebivolol significantly lowered systolic BP in sildenafil responders (-44±13 mm Hg) but not in nonresponders (1±11 mm Hg). Despite lowering nighttime BP, nebivolol did not worsen morning orthostatic tolerance compared with placebo. In conclusion, nebivolol effectively lowered supine hypertension in autonomic failure, independent of β1-blockade. These results are consistent with the hypothesis that NO potentiation contributes significantly to the antihypertensive effect of nebivolol.

Diabetic cardiovascular autonomic neuropathy: clinical implications

Diabetic cardiovascular autonomic neuropathy (DCAN), the impairment of the autonomic balance of the cardiovascular system in the setting of diabetes mellitus (DM), is frequently observed in both Type 1 and 2 DM, has detrimental effects on the quality of life and portends increased mortality. Clinical manifestations include: resting heart rate disorders, exercise intolerance, intraoperative cardiovascular lability, orthostatic alterations in heart rate and blood pressure, QT-interval prolongation, abnormal diurnal and nocturnal blood pressure variation, silent myocardial ischemia and diabetic cardiomyopathy. Clinical tests for autonomic nervous system evaluation, heart rate variability analysis, autonomic innervation imaging techniques, microneurography and baroreflex analysis are the main diagnostic tools for DCAN detection. Aldose reductase inhibitors and antioxidants may be helpful in DCAN therapy, but a regular, more generalized and multifactorial approach should be adopted with inclusion of lifestyle modifications, strict glycemic control and treatment of concomitant traditional cardiovascular risk factors, in order to achieve the best therapeutic results. In the present review, the authors provide aspects of DCAN pathophysiology, clinical presentation, diagnosis and an algorithm regarding the evaluation and management of DCAN in DM patients.

Renal function in advanced heart failure

Despite recent advances with neurohormonal antagonists and devices, the prognosis of patients with advanced heart failure (HF) remains grave. Renal dysfunction is a common comorbid condition in HF and is associated with adverse outcomes. Current evidence indicates that intrinsic renal disease and inflammation in HF makes the kidney susceptible to hemodynamic compromise and congestion and contributes to a great extent to the development of renal dysfunction. Relief of congestion requires combination treatment with diuretics, neurohormonal antagonists, and occasionally vasodilators as well as inotropes. However, high doses of diuretics may accelerate the development of renal dysfunction by increasing neurohumoral activity and inducing renal structural and functional changes. Ultrafiltration should be reserved for patients with true diuretic resistance. Finally, early identification of the "patient at risk" remains a challenging issue and is limited by the currently used conventional parameters of renal function. However, novel biomarkers of acute kidney ischemia and/or injury are emerging and promise to become a diagnostic option for this patient population.

Reversal of subclinical left ventricular dysfunction by antihypertensive treatment: a prospective trial of nebivolol against metoprolol

OBJECTIVES

To assess the effects of antihypertensive treatment on subclinical left ventricular dysfunction and to compare the effects of nebivolol with metoprolol.

METHODS

This is a prospective, randomized, parallel, active-controlled, PROBE design study (ClinicalTrials.org: NCT00942487) in 60 patients (53±9 years, 67% men) with arterial hypertension, left ventricular hypertrophy, normal ejection fraction, and no coronary heart disease, randomized to either a nebivolol-based or a metoprolol-based treatment, who had conventional and tissue Doppler echocardiography, at rest and during dobutamine stress, at baseline and after 6 months.

RESULTS

SBP and DBP, and resting heart rate decreased by 13, 13, and 12%, respectively, on nebivolol, and by 11, 13, and 7%, respectively, on metoprolol (all, P<0.01). Mean longitudinal early diastolic velocity increased by 16% (P<0.05) on nebivolol compared with 9% (P=not significant) on metoprolol (P=not significant for intergroup differences), whereas flow propagation velocity increased by 34% on nebivolol (P<0.05) and did not change on metoprolol (P<0.01 for intergroup differences). Mean longitudinal displacement increased by 10% on nebivolol (P<0.05) and did not change on metoprolol (P<0.05 for intergroup differences), whereas ejection time increased by 5% on nebivolol (P<0.05) and did not change on metoprolol. All the other parameters of left ventricular function were not different between the two treatment arms.

CONCLUSION

Patients with mild-to-moderate hypertension have a beneficial effect from 6-month antihypertensive treatment on diastolic longitudinal left ventricular function; effects are significant with nebivolol, but not with metoprolol.

Managing beta-blockers in acute heart failure: when to start and when to stop?

The role of beta-blockers in heart failure has been long debated. Data from chronic heart failure studies clearly indicate that beta-blockers save lives. However, data concerning use of beta-blockers in patients with acute heart failure are limited, and only recently have emerged to help guide therapy. In this review, we provide an overview of when to stop and when to start beta-blockers in patients with acute heart failure.

Nebivolol in chronic heart failure: current evidence and future perspectives

IMPORTANCE OF THE FIELD

Chronic activation of the sympathetic nervous system leads to deterioration of cardiovascular function in heart failure patients. In systolic heart failure, beta-blockers were proven to be effective in decreasing the number of deaths and improving morbidity. However, beta-blockers are a heterogeneous drug group, consisting of agents with different selectivity for adrenergic receptors and/or additional effects in heart or peripheral circulation.

AREAS COVERED IN THE REVIEW

We describe the role of the sympathetic nervous system, beta-blockers and specifically nebivolol in chronic heart failure.

WHAT THE READER WILL GAIN

Nebivolol is a third-generation beta-blocker, with high beta(1)/beta(2) selectivity. Moreover, it has important vasodilating properties, by stimulating the production of nitric oxide. Smaller studies have already shown beneficial effects of nebivolol treatment on surrogate end points in heart failure patients. The recently published SENIORS (Phase III) study in an elderly heart failure population demonstrated a decreased number of clinical events in patients treated with nebivolol. Importantly, this effect was observed in patients with both impaired and preserved left ventricular systolic function.

TAKE HOME MESSAGE

Specific beta-blockers may have distinct effects in various subgroups of heart failure patients. So far, nebivolol is the only beta-blocker to have been shown effective in elderly heart failure patients, regardless of their left ventricular ejection fraction.

[Advantages of vasodilating beta-blockers in congestive heart failure]

Beta-blockers play a pivotal role in the treatment of chronic systolic heart failure. However, the pharmacological family of beta-blockers is inhomogeneous regarding their pharmacological properties and their clinical effects can differ substantially according to different pharmacological properties. Because of vasodilator effects, the third generation of beta-blockers has additional potential across the cardiovascular diseases, from hypertension to heart failure. Nebivololol has both high selectivity for beta1-adrenergic receptors, no intrinsic sympathetic activity and ability to stimulate endothelial nitric oxide production. Such properties result in specific hemodynamic effects compared with others beta-blockers. Such properties also result in both high tolerability and positive metabolic effects which are crucial in high-risk groups. In the SENIORS trial, nebivolol demonstrated its efficacy and high tolerability in elderly patients with chronic heart failure irrespective of the left ventricular ejection fraction. More clinical trials would be useful to exhibit specific benefits of nebivolol in other high-risk groups of patients.

The sympathetic nervous system in heart failure physiology, pathophysiology, and clinical implications

Heart failure is a syndrome characterized initially by left ventricular dysfunction that triggers countermeasures aimed to restore cardiac output. These responses are compensatory at first but eventually become part of the disease process itself leading to further worsening cardiac function. Among these responses is the activation of the sympathetic nervous system (SNS) that provides inotropic support to the failing heart increasing stroke volume, and peripheral vasoconstriction to maintain mean arterial perfusion pressure, but eventually accelerates disease progression affecting survival. Activation of SNS has been attributed to withdrawal of normal restraining influences and enhancement of excitatory inputs including changes in: 1) peripheral baroreceptor and chemoreceptor reflexes; 2) chemical mediators that control sympathetic outflow; and 3) central integratory sites. The interface between the sympathetic fibers and the cardiovascular system is formed by the adrenergic receptors (ARs). Dysregulation of cardiac beta(1)-AR signaling and transduction are key features of heart failure progression. In contrast, cardiac beta(2)-ARs and alpha(1)-ARs may function in a compensatory fashion to maintain cardiac inotropy. Adrenergic receptor polymorphisms may have an impact on the adaptive mechanisms, susceptibilities, and pharmacological responses of SNS. The beta-AR blockers and the inhibitors of the renin-angiotensin-aldosterone axis form the mainstay of current medical management of chronic heart failure. Conversely, central sympatholytics have proved harmful, whereas sympathomimetic inotropes are still used in selected patients with hemodynamic instability. This review summarizes the changes in SNS in heart failure and examines how modulation of SNS activity may affect morbidity and mortality from this syndrome.

Efficacy and tolerability of nebivolol compared with other antihypertensive drugs: a meta-analysis

BACKGROUND AND OBJECTIVE

Lowering BP to normal levels without quality of life deterioration is the most important means of reducing cardiovascular risk. Recent studies have challenged the position of beta-adrenoceptor antagonists (beta-blockers) as first-line antihypertensive drugs. Nebivolol is a third-generation, highly selective beta(1)-blocker that causes vasodilation through nitric oxide (NO) release. This meta-analysis investigates the efficacy and tolerability of nebivolol compared with other antihypertensive drugs and placebo in patients with hypertension.

METHODS

Twelve randomized controlled studies were included in which nebivolol 5 mg once daily was compared with the recommended clinical doses of other antihypertensive drugs (n = 9), placebo (n = 2), and both (n = 1). The clinical studies were selected after a MEDLINE search up to 2007 using the key words 'nebivolol' and 'hypertension.'

RESULTS

Antihypertensive response rates (the percentage of patients achieving target BP levels or a defined DBP reduction) were higher with nebivolol than with ACE inhibitors (odds ratio [OR] 1.92; p = 0.001) and all antihypertensive drugs combined (OR 1.41; p = 0.001) and similar to beta-blockers, calcium channel antagonists (CCAs) and the angiotensin receptor antagonist (ARA) losartan. Moreover, a higher percentage of patients receiving nebivolol achieved target BP levels compared with patients treated with losartan (OR 1.98; p = 0.004), CCAs (OR 1.44; p = 0.024), and all antihypertensive drugs combined (OR 1.35; p = 0.012). The percentage of patients experiencing adverse events did not differ between nebivolol and placebo; adverse event rates were significantly lower with nebivolol than losartan (OR 0.52; p = 0.016), other beta-blockers (OR 0.56; p = 0.007), nifedipine (OR 0.49; p < 0.001), and all antihypertensive drugs combined (OR 0.59; p < 0.001).

CONCLUSION

Results of previous pharmacokinetic studies suggest that nebivolol 5 mg may not conform completely to the definition of a classic beta-blocker demonstrating additional antihypertensive effect due to endothelial NO release-mediated vasodilation. This meta-analysis showed that nebivolol 5 mg achieved similar or better rates of treatment response and BP normalization than other drug classes and other antihypertensive drugs combined, with similar tolerability to placebo and significantly better tolerability than losartan, CCAs, other beta-blockers, and all antihypertensive drugs combined. Although not definitive, this meta-analysis suggests that nebivolol 5 mg is likely to have advantages over existing antihypertensives and may have a role in the first-line treatment of hypertension.