The role of beta-blockers as a cornerstone of cardiovascular therapy

The beta-adrenergic blockade as a therapeutic approach first emerged in the 1950s. During the past five decades, the total number of indications that have been suggested, and the remarkable number approved by regulatory agencies, places beta-blockade far ahead of all competing treatments, not only in the cardiovascular area, but in all of therapeutics. Differentiation of beta-adrenergic blocking agents has been made on the basis of beta1 selectivity, duration of action, intrinsic sympathomimetic activity, lipophilicity, and whether or not the beta-adrenergic blocking action is accompanied by an alpha-adrenergic blocking action. With the development of nebivolol, a beta-adrenergic blocking agent that also activates nitric oxide synthase in blood vessels, comes a new therapeutic option. Endothelial dysfunction with loss of nitric oxide production is a common feature in many cardiovascular diseases. This fascinating class of drugs continues to provide us with new and important therapeutic opportunities.

Exploring vascular benefits of endothelium-derived nitric oxide

Although the regulation of arterial blood flow has been a subject of intensive medical research, the precise circulatory mechanisms involved are still not fully understood. It has been increasingly recognized that the endothelium plays a vital role in regulating vascular tone, structure, and function. A seminal discovery was made with the identification of endothelium-derived relaxing factor, a key mediator of vasodilation, which was later identified as nitric oxide (NO). Nitric oxide is synthesized from the amino acid L-arginine in the endothelium. Decreased bioavailability of NO is associated with arterial stiffness, hypertension, atherosclerosis, and cardiovascular disease (CVD). Nebivolol is a novel beta-blocker that is highly selective for beta1-adrenergic receptors. Nebivolol also causes vasodilation through a mechanism involving endothelium-derived NO. In clinical studies in hypertensive subjects, nebivolol significantly improves vasodilator responses to endothelium-dependent agonists such as acetylcholine. In addition, nebivolol significantly reduces pulse wave velocity (PWV), a measure of arterial stiffness, whereas the beta-blocker atenolol has no effect on PWV. Because endothelial dysfunction and arterial stiffness play an integral part in the early atherosclerotic process and are associated with poor outcomes and increased mortality, independent of blood pressure, the ability of nebivolol to enhance release of endothelium-derived NO may have significant clinical implications for the use of this agent in the treatment of hypertension and CVD.

Economic evaluation of nebivolol in the treatment of hypertension

OBJECTIVE

To examine the economic consequences of effective antihypertensive treatment using the novel vasodilating beta1-adrenoceptor antagonist nebivolol (Nebilet) from the perspective of the healthcare provider.

METHODS

The evaluation was based on a postmarketing surveillance study in Germany involving 8682 moderately hypertensive patients. Using the Framingham Risk Model, the antihypertensive effectiveness of nebivolol after 6 weeks of treatment was extrapolated to estimate the reductions in 10-year risks of cardiovascular events. Data sources included direct costs for medical and invasive cardiovascular interventions in Germany, costs of therapy in the US and the UK, and estimates on the prevalence of cardiovascular events issued by the American Heart Association.

RESULTS

Six-week antihypertensive treatment resulted in a DBP reduction of 13.7 mm Hg. The rate of responders, defined as those patients achieving DBP <90 mm Hg, was 70%. SBP was reduced by 26.1 mm Hg. According to the Framingham Risk Model, 313 deaths would be avoided. Coronary heart disease (CHD) could be reduced by 94 cases (from 1339 to 1245 events) and 150 strokes would be avoided (from 518 to 368 events) in a 10-year period. This reduction of 244 cardiovascular events among the 8682 patients investigated corresponded to cost savings of between Euro 250,000 and Euro 2.5 million, depending on the healthcare environment and the intervention applied.

CONCLUSION

Treatment of moderately hypertensive patients with nebivolol can be considered cost effective. Nebivolol has the potential to decrease the overall long-term costs of medical care for patients with hypertension.

Effect of nebivolol on cardiovascular changes associated with a rat model of insulin-resistance

Nebivolol is a vasodilator that combines beta-adrenergic blocking activity with a relaxant effect on vascular smooth muscle cells (VSMC) mediated by the endothelial nitric oxide (NO) pathway. FFR provide a model of dietary-induced insulin-resistance syndrome, which has been used to study the pathophysiological mechanisms associated with this syndrome. Our main objective was to examine the effect of long-term administration of nebivolol on metabolic and cardiovascular variables in fructose-fed rats (FFR), a model in which an altered bioavailability of NO has been already described. Male Wistar rats were randomly assigned to 4 groups (n = 8 each): I. Control (C); II. Control + nebivolol (C+N): 1 mg/kg(-1) x day(-1) in drinking water during the last 4 weeks. III. FFR: rats receiving fructose in drinking water as a 10% (w/v) solution during 8 weeks, and IV. FFR+N: idem II plus III. During the 8 weeks experimental period, variations in systolic blood pressure (SBP), glucose tolerance test (GTT) and plasma thiobarbituric acid-reactive substances (TBARS) were assessed. At the end of this experimental period, rats were killed and heart and kidneys were excised for calculation of relative heart weight (RHW) and histological evaluation of lumen to media ratio (L/M) in renal arteries. Rats from FFR group increased their SBP and RHW, showed glucose intolerance and an increment in lipid peroxidation. Moreover, FFR showed vascular remodeling in renal arteries evidenced by changes in L/M. Although the metabolic changes were not reverted by the administration of nebivolol, this drug successfully decreased SBP, TBARS levels and reverted structural changes such as cardiac hypertrophy and renal arterial remodeling. Data demonstrate that nebivolol administration could participate in the reversion of cardiovascular structural changes associated with the insulin-resistance syndrome.

Comparative efficacy of nebivolol versus carvedilol on left ventricular function and exercise capacity in patients with nonischemic dilated cardiomyopathy. A 12-month study

PURPOSE

To compare the efficacy of nebivolol versus carvedilol on left ventricular (LV) function and exercise capacity in patients with nonischemic dilated cardiomyopathy (NIDC).

METHODS

After enrollment in this double-blind trial, 72 patients, aged 55 +/- 9.5 years, with NIDC, LV ejection fraction (LVEF) < 45%, New York Heart Association classes II to III, were randomized to either nebivolol (34 patients) or carvedilol (38 patients) and were evaluated through echocardiography and exercise tests at baseline and 3 and 12 months after treatment.

RESULTS

During follow-up, 4 patients discontinued nebivolol, although 3 patients stopped carvedilol. Patients in both the nebivolol and carvedilol groups showed a steady improvement in New York Heart Association class (P = .002 and < .001, at 12 months, respectively) and LVEF (P = .001 and < .001, at 12 months, respectively) that became significant from 3-month follow-up on. Intergroup analysis showed that carvedilol group had a greater increase in LVEF at 3 (P = .04) and 12 (P = .02) months' follow-up compared with nebivolol group. Advanced diastolic dysfunction regressed to earlier stages in carvedilol patients after 3 (P = .02) and 12 (P = .01) months' treatment, whereas in the nebivolol group, a significant improvement in diastolic dysfunction was found at the 12 months' follow-up (P = .02). Exercise duration improved in both groups at 12 months' follow-up (both P = .01), but in the nebivolol group, there was an initial deterioration at 3 months (P = .07).

CONCLUSIONS

Both nebivolol and carvedilol appear relatively safe, with beneficial effects on LV systolic and diastolic function as well as exercise capacity in patients with NIDC after 12 months' treatment. However, carvedilol exhibits more favorable effects on LV function than does nebivolol.

Rapid quantification of nebivolol in human plasma by liquid chromatography coupled with electrospray ionization tandem mass spectrometry

A simple, sensitive and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric method was developed and validated for the quantitation of nebivolol in human plasma. The method involved a simple single-step liquid-liquid extraction with diethyl ether/dichloromethane (70/30). The analyte was chromatographed on Waters symmetry C18 reversed-phase chromatographic column by isocratic elution with water:acetonitrile:formic acid (30:70:0.03, v/v) and analyzed by mass spectrometry in the multiple reaction monitoring mode. The precursor to product ion transitions of m/z 406.4-151.5 and m/z 409.1-228.1 were used to measure the analyte and the internal standard (I.S.), respectively. The chromatographic runtime was 2 min and the weighted (1/x2) calibration curves were linear over the range 50-10,000 pg/mL. The method was validated in terms of accuracy, precision, absolute recovery, freeze-thaw stability, bench-top stability and re-injection reproducibility. The limit of detection and lower limit of quantification in human plasma were 10 and 50 pg/mL, respectively. The within- and between-batch accuracy and precision were found to be well within acceptable limits (<10%). The analyte was stable after three freeze-thaw cycles (deviation <10%). The average absolute recoveries of nebivolol and tamsulosin, used as an internal standard, from spiked plasma samples were 73.4+/-3.7 and 72.1+/-2.0%, respectively. The assay method described here was applied to study the pharmacokinetics of nebivolol.

Effects of nebivolol on left ventricular function in elderly patients with chronic heart failure: results of the ENECA study

AIM

To examine the effect of the beta(1)-selective beta-blocker nebivolol, administered as add-on therapy, on left ventricular function in 260 elderly patients (>65 years) with chronic heart failure (CHF).

METHODS

The principal inclusion criteria were (1) NYHA class II-IV CHF and (2) a left ventricular ejection fraction (LVEF) <= 35%. The primary end-point was the change in LVEF in response to nebivolol treatment for 8 months.

RESULTS

Baseline LVEF values in the two groups were as follows: nebivolol 25.41+/-7.09% and control 26.41+/-5.55%. LVEF improved significantly (p=0.027) more in the nebivolol group (6.51+/-9.15%) than in the control group (3.97+/-9.20%), the relative improvement (percentage increase in the initial value) being 35.70+/-57.62% in the nebivolol group and 19.19+/-40.96% (p=0.008) in the placebo group. Examination of different subgroups did not reveal any heterogeneity in the effects of nebivolol treatment vs. placebo treatment. There were no significant differences between the nebivolol and placebo groups as concerns the changes in clinical status, quality of life, or safety parameters.

CONCLUSION

The findings of the ENECA study confirmed that nebivolol significantly improved cardiac function and proved to be safe and well tolerated in elderly patients with signs of CHF and an impaired LVEF.

Effect of Nebivolol and Atenolol on Brachial Artery Flow-Mediated Vasodilation in Patients with Coronary Artery Disease

Endothelial dysfunction is considered to be the first step in atherogenesis as well as a predictor of adverse cardiovascular events in patients with coronary artery disease (CAD), while endothelial function improvement is associated with improved clinical outcome. Nebivolol is a beta1-adrenoreceptor antagonist with an independent beneficial action on endothelial function, increasing nitric oxide bioavailability. The aim of the present study was to examine the effects of nebivolol on endothelial function in the brachial artery in patients with CAD compared with another selective beta1 adrenergic receptor antagonist, atenolol. Thirty-five patients with stable CAD were randomized to receive either 5 mg nebivolol (n = 17) or 50 mg atenolol (n = 18) daily for 4 weeks. Each patient underwent measurement of endothelial function by means of flow-mediated dilatation (FMD) of the brachial artery before and after 4 weeks of treatment. All vasoactive drugs and cardiovascular risk factors were comparable in the two groups. No significant differences were observed between the two groups at baseline in FMD. In the atenolol group FMD remained unchanged at the end of the 4-week treatment, but in patients treated with nebivolol FMD showed a significant increase by the end of the treatment period (3.9 +/- 2.7% vs. 5.6 +/- 2.9%, p = 0.047) leading to a significantly higher value compared to patients treated with atenolol (5.6 +/- 2.9% vs. 3.4 +/- 3.2%, p = 0.041).Beta(1) blockade by nebivolol but not atenolol improves endothelial dysfunction in patients with CAD, an effect that might further reduce the risk for cardiovascular events in patients with CAD.

Autonomic effects of nebivolol versus atenolol in healthy subjects

PURPOSE

Nitric oxide may stimulate sympathoinhibitory reflexes. Nebivolol is a beta(1) selective adrenergic receptor antagonist with ancillary vasodilating properties by modulating nitric oxide secretion. We investigated whether nebivolol affects autonomic function differently compared with atenolol, another selective beta(1)-blocker without vasorelaxant actions.

METHODS

Fourteen healthy volunteers (9 men, 5 women; 25 +/- 3.7 years) received single oral doses of 5 mg nebivolol, 50 mg atenolol, and 100 mg atenolol, each taken for a 2-week period. Heart rate variability (HRV) measurements in time- (SDNN; rMSSD; pNN50) and frequency-domain (low frequency-LF; high frequency-HF; LF/HF ratio) were used to study the autonomic effects of the three regimens on the same patients from serial 24-hour ECGs.

RESULTS

Both nebivolol and atenolol, the 50 mg dose as well as the 100 mg dose, produced similar decreases in heart rate compared with baseline throughout the 24-h period (from 82 +/- 9 beats/min to 72 +/- 7 beats/min, 69 +/- 9, and 68 +/- 8 beats/min, respectively, p < 0.001). Overall, the administration of each beta -blocker led to directionally similar increases in the HRV variables, which were most significant following 100 mg atenolol. Nebivolol and the 50 mg dose of atenolol produced similar increases in rMSSD and pNN50 during the entire 24-h period, and in HF power, particularly during the nighttime (p < 0.05). However, the coefficient of HF variance resulted in similar values after either beta -blocker regimen. The LF/HF ratio was most reduced throughout the 24-h period following 100 mg atenolol (p < 0.001), and to a similar extent decreased in the nighttime following nebivolol and atenolol 50 mg (p < 0.01).

CONCLUSIONS

Nebivolol 5 mg exerts similar effects on time and frequency domain indexes of HRV as 50 mg atenolol. Nebivolol attenuates sympathetic tone, but does not appear to promote vagal activity more than atenolol.

Practical recommendations for the use of ACE inhibitors, beta-blockers, aldosterone antagonists and angiotensin receptor blockers in heart failure: Putting guidelines into practice

Surveys of prescribing patterns in both hospitals and primary care have usually shown delays in translating the evidence from clinical trials of pharmacological agents into clinical practice, thereby denying patients with heart failure (HF) the benefits of drug treatments proven to improve well-being and prolong life. This may be due to unfamiliarity with the evidence-base for these therapies, the clinical guidelines recommending the use of these treatments or both, as well as concerns regarding adverse events. ACE inhibitors have long been the cornerstone of therapy for systolic HF irrespective of aetiology. Recent trials have now shown that treatment with beta-blockers, aldosterone antagonists and angiotensin receptor blockers also leads to substantial improvements in outcome. In order to accelerate the safe uptake of these treatments and to ensure that all eligible patients receive the most appropriate medications, a clear and concise set of clinical recommendations has been prepared by a group of clinicians with practical expertise in the management of HF. The objective of these recommendations is to provide practical guidance for non-specialists, in order to increase the use of evidenced based therapy for HF. These practical recommendations are meant to serve as a supplement to, rather than replacement of, existing HF guidelines.

Quality of life and antihypertensive effect with nebivolol and losartan

BACKGROUND

Quality of life and antihypertensive effect, two important therapeutic goals, were determined with the third generation beta-blocker nebivolol and the angiotensin receptor blocker losartan are compared.

METHODS

In a double-blind, randomized, parallel group study 314 patients with hypertension were treated for 12 weeks with 5 mg of nebivolol or 50 mg of losartan once daily. If after 6 weeks diastolic blood pressure (BP) was not normalized 12.5 mg of hydrochlorothiazide once daily was added. Effects of treatment were compared using analysis of variance.

RESULTS

Both drugs decreased systolic BP similarly. The decrease in diastolic BP was greater (P < .0001) with nebivolol (-12 mm Hg after 6 and 12 weeks) than with losartan (-8 and -10 mm Hg after 6 and 12 weeks, respectively). Quality of life parameters did not differ between the two treatments. This was true after 6 and 12 weeks of treatment and results did not change when corrected for different effects on BP. Aspects of quality of life including questions on sexual function did not differ between the two treatments except for headache occurring less frequently (P < .05) in patients on nebivolol monotherapy at 6 weeks.

CONCLUSIONS

At advocated doses nebivolol and losartan decrease systolic BP similarly, whereas the decrease in diastolic BP was slightly greater with nebivolol. Overall quality of life parameters did not differ between nebivolol and losartan. The effect on sexual function did not differ between the two treatments and less patients had headache with nebivolol than with losartan after 6 weeks of monotherapy.

Effects of Nebivolol on left ventricular function and exercise capacity in patients with non-ischaemic dilated cardiomyopathy. A randomised placebo-controlled study

INTRODUCTION

This study assessed the effects of Nebivolol on left ventricular (LV) function and exercise capacity in patients with non-ischaemic dilated cardiomyopathy (NIDC).

METHODS

After enrolment in this double-blind trial, 60 patients, aged 55 +/- 9.5 years, with angiographically proven NIDC, LV ejection fraction (EF) < 45%, NYHA class II-III, were randomised to either Nebivolol (target dose 5 mg) or placebo and were evaluated using echocardiography and exercise tests over 3 months.

RESULTS

There were no baseline differences between the 2 groups regarding NYHA class, heart rate (HR), blood pressure (BP), LVEF or other echocardiographic variables. During follow-up, 4 patients in the Nebivolol and 5 in the placebo group discontinued treatment. After 3-months' treatment a significant decrease in NYHA class (p = 0.001), resting HR (p = 0.03), systolic and diastolic BP (both p < 0.001), left atrial diameter (p = 0.01) and LV end-systolic volume (p = 0.046), and an increase in LVEF (p = 0.01) were observed in the Nebivolol group compared to placebo. The atrial contribution to total LV filling (p = 0.007) and the pulmonary venous (PV) systolic wave velocity (p = 0.007) increased, whereas the atrial PV component decreased (p < 0.001) in the Nebivolol patients compared to placebo. Exercise duration decreased at 3 months (p = 0.01) compared to placebo, probably as a result of reduced maximal exercise HR (p < 0.001).

CONCLUSIONS

Nebivolol is a safe and well-tolerated drug that improves NYHA class, systolic and diastolic LV function in NIDC patients, although it is associated with a lower maximal exercise duration at 3 months.

Effects of nebivolol on artery hypertension--multicentre study Bosnia and Herzegovina

Hypertension is a major risk factor for cardiovascular diseases; drugs that reduce blood pressure and simultaneously improve or reverse endothelian dysfunction, as nebivolol, may be advantageous in terms of cardiovascular protection. The objective of this study is to show the anti-hypertensive efficacy and safety of nebivolol (5 mg once a day) given to patients with arterial hypertension for 3 months. It should also provide information about drug's influence on laboratory tests--fasting blood glucose and serum cholesterol, triglyceride and creatinine concentrations. Six centers--Tuzla, Sarajevo, Mostar, Bihac, Zenica and Banja Luka participated in this prospective study with follow-up period of 3 months that included 3 visits. The study group consisted of 328 hypertensic patients. Results showed a significant decrease in both systolic and diastolic blood pressure and heart rate at the end of the study. Fasting blood glucose level and serum cholesterol, triglyceride and creatinine changed significantly during the study, with lower levels of all the tests. Nebivolol seems to be free from some of the problems that generally accompany not only the classical beta- blockers but sometimes also newer classes of antihypertensive drugs. With its high anti-hypertensive efficiency and safety, and presence of statically significant difference in laboratory tests and beneficial effects, absence of adverse interaction with glucose and lipid metabolism, patients treated with Nebivolol may show an optimal adherence to therapy.

Nebivolol: a review

Nebivolol is a vasodilating beta-blocker, which can be distinguished from other beta-blockers by its haemodynamic profile. It combines beta-adrenergic blocking activity with a vasodilating effect mediated by the endothelial L-arginine nitric oxide (NO) pathway. The blood pressure lowering effect of nebivolol is linked to a reduction in peripheral resistance and an increase in stroke volume and preservation of cardiac output. The effects of nebivolol have been compared with other beta-blockers and also with other classes of antihypertensive agents. In general, response rates to treatment are higher and the frequency and severity of adverse events are either comparable or lower with nebivolol. Endothelium-derived NO is important in the regulation of large arterial stiffness, which in turn is a major risk factor for cardiovascular disease. Therefore, antihypertensive drugs, such as nebivolol, that also improve endothelial function and decrease arterial stiffness, may contribute to a reduction in cardiovascular risk.

Involvement of nitric oxide in both central and peripheral haemodynamic effect of d/l-nebivolol and its enantiomers in rats

The cardiovascular profile of the racemate D/L-nebivolol and its enantiomers administered by intravenous (i.v.) or by intracerebroventricular (i.c.v.) route was investigated in anaesthetized normotensive rats. D/L-Nebivolol (0.1-0.5 mg/kg) induced a dose-related reduction in blood pressure when administered by i.c.v. route. These hypotensive effects were more marked as compared to those achieved by peripheral administration of D/L-nebivolol (0.1-1 mg/kg i.v.). Both enantiomers contributed to the hypotensive effect of D/L-nebivolol by i.c.v. route, while the effects of the drug on blood pressure by i.v. route were due to the d-enantiomer. The bradycardic effect of the racemic form given i.v. was dose-related and, at the highest dose (1 mg/kg), was more pronounced as compared to i.c.v. route. D-Nebivolol was responsible for chronotropic effects by both the i.v. and i.c.v. route, although by i.c.v. route L-nebivolol also induced a reduction in heart rate. The nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) administered at 5 mg/kg i.v. bolus + 0.1 mg/kg/min infusion or at 2.5 mg/kg i.c.v. counteracted the effects of D/L-nebivolol (either 1 mg/kg i.v. or 0.5 mg/kg i.c.v.) on blood pressure, while it did not inhibit the cardiovascular changes induced by isoprenaline (300 ng/kg i.v.) or calcitonin gene-related peptide (CGRP; 400 ng/kg i.v.). In addition, i.c.v. effects of D/L-nebivolol on blood pressure and heart rate were not affected by pre-treatment with atropine (2 mg/kg i.v.). The present findings demonstrate that D/L-nebivolol produced haemodynamic changes following both peripheral and central administration; these latter findings are mainly due to its L-enantiomer and these effects involve the L-arginine/nitric oxide pathway.

Nebivolol decreases oxidative stress in essential hypertensive patients and increases nitric oxide by reducing its oxidative inactivation

OBJECTIVE

To obtain further insight into the mechanism underlying the vasodilator effect of nebivolol. Since oxidative inactivation of nitric oxide (NO) is regarded as an important cause of its decreased biological activity, we studied (1) the effect of nebivolol on some oxidative parameters in essential hypertensive patients; (2) the effect of plasma of nebivolol-treated patients on reactive oxygen species production and NO availability in endothelial cells.

METHODS

A total of 20 healthy subjects and 20 matched essential hypertensive patients treated with atenolol or nebivolol according to a double-blind, randomized design participated in the study. We measured low-density lipoprotein (LDL) and plasma hydroperoxides, 8-isoprostanes, oxidized LDL, susceptibility of LDL to oxidation (lag phase) and LDL vitamin E and the effect of plasma of nebivolol- and atenolol-treated patients on reactive oxygen species production and NO availability in endothelial cells exposed to oxidative stress.

RESULTS

In hypertensive patients, nebivolol and atenolol significantly reduced blood pressure values after 4 weeks of treatment. Plasma and LDL hydroperoxides, plasma 8-isoprostanes, plasma ox-LDL and LDL lag phase were significantly improved only in the patients receiving nebivolol compared with the atenolol group. Similarly there was a reduction of reactive oxygen species (ROS) and O2*- concentration in endothelial cells exposed to oxidative stress after incubation of the cells with plasma of the patients enrolled in the trial only in the patients receiving nebivolol compared to atenolol group. Furthermore, the reduction of basal and stimulated NO induced by oxidative stress in endothelial cells was significantly lower in the patients receiving nebivolol compared to atenolol group.

CONCLUSIONS

The findings of the present study indicate that nebivolol, through its antioxidant properties, increases NO also by decreasing its oxidative inactivation.

Clinical trials update from the European Society of Cardiology: SENIORS, ACES, PROVE-IT, ACTION, and the HF-ACTION trial

This article provides information and a commentary on landmark trials presented at the European Society of Cardiology Congress in August 2004, relevant to the pathophysiology, prevention or treatment of heart failure. The SENIORS trial suggests that nebivolol is well tolerated and effective in older patients with heart failure, even if left ventricular systolic function is not markedly depressed. However, patients aged >75 years appeared to gain less benefit. Further data on the effects of nebivolol on symptoms and quality of life are awaited. Two new trials of long-term antibiotic prophylaxis after myocardial infarction (ACES and PROVE-IT) showed no benefit. The ACTION trial showed no reduction in serious cardiovascular events with nifedipine GITS in patients with chronic stable angina, despite a substantial reduction in blood pressure. The HF-ACTION trial announced that the first 700 patients of a projected 3000 had been randomised to either an exercise program or encouragement to exercise but without a formal program. The primary outcome measure is death or hospitalisation for any reason.

Left ventricular mass and mechanics in mild-to-moderate hypertension: effect of nebivolol versus telmisartan

BACKGROUND

The aim of this study was to compare the effects of nebivolol and telmisartan on left ventricular mass (LVM) and midwall mechanics in mild-to-moderate hypertension.

METHODS

A total of 40 patients with mild-to-moderate hypertension were randomized to receive either nebivolol (2.5 to 5.0 mg/day) or telmisartan (40 to 80 mg/day) to achieve a target diastolic blood pressure of <90 mm Hg. Blood pressure (BP) was measured with sphygmomanometry, and LVM and midwall fractional shortening (mFS) were estimated by two-dimensionally guided M-mode echocardiography at baseline and at 3-month follow-up.

RESULTS

Age, sex distribution, and baseline SBP and DBP and heart rate were similar in the two groups. Both nebivolol and telmisartan reduced systolic (156 +/- 7 v 124 +/- 8 mm Hg, P < .01, and 153 +/- 5 v 120 +/- 7 mm Hg, P < .01, respectively) and DBP (99 +/- 4 v 80 +/- 2 mm Hg, P < .01 and 98 +/- 2 v 80 +/-2 mm Hg, P < .01, respectively) and increased mFS (16% +/- 2% v 19% +/- 2%, P < .01, and 15% +/- 2% v 18% +/- 2%, P < .01, respectively). The LVM indices decreased significantly with both nebivolol (98 +/- 16 v 84 +/- 13 g/m(2), P < .01) and telmisartan (97 +/- 13 v 83 +/- 8 g/m(2), P < .01). We found that mFS was inversely related to DBP in the nebivolol but not in the telmisartan group.

CONCLUSIONS

In mild-to-moderate hypertension, nebivolol and telmisartan are equally effective in reducing BP and increasing mFS. There may be differences between nebivolol and telmisartan regarding the mechanism of increase in mFS.

Randomized trial to determine the effect of nebivolol on mortality and cardiovascular hospital admission in elderly patients with heart failure (SENIORS)

AIMS

Large randomized trials have shown that beta-blockers reduce mortality and hospital admissions in patients with heart failure. The effects of beta-blockers in elderly patients with a broad range of left ventricular ejection fraction are uncertain. The SENIORS study was performed to assess effects of the beta-blocker, nebivolol, in patients >/=70 years, regardless of ejection fraction.

METHODS AND RESULTS

We randomly assigned 2128 patients aged >/=70 years with a history of heart failure (hospital admission for heart failure within the previous year or known ejection fraction </=35%), 1067 to nebivolol (titrated from 1.25 mg once daily to 10 mg once daily), and 1061 to placebo. The primary outcome was a composite of all cause mortality or cardiovascular hospital admission (time to first event). Analysis was by intention to treat. Mean duration of follow-up was 21 months. Mean age was 76 years (SD 4.7), 37% were female, mean ejection fraction was 36% (with 35% having ejection fraction >35%), and 68% had a prior history of coronary heart disease. The mean maintenance dose of nebivolol was 7.7 mg and of placebo 8.5 mg. The primary outcome occurred in 332 patients (31.1%) on nebivolol compared with 375 (35.3%) on placebo [hazard ratio (HR) 0.86, 95% CI 0.74-0.99; P=0.039]. There was no significant influence of age, gender, or ejection fraction on the effect of nebivolol on the primary outcome. Death (all causes) occurred in 169 (15.8%) on nebivolol and 192 (18.1%) on placebo (HR 0.88, 95% CI 0.71-1.08; P=0.21).

CONCLUSION

Nebivolol, a beta-blocker with vasodilating properties, is an effective and well-tolerated treatment for heart failure in the elderly.

The cellular mechanisms involved in the vasodilator effect of nebivolol on the renal artery

Nebivolol is known as a highly selective beta1-adrenoceptor antagonist. Based on the reported vasodilator effect of nebivolol, we examined the cellular mechanisms by which the drug induces renal artery vasodilation, an issue of potential relevance for condition associated with high blood pressure. To this purpose, myograph and patch-clamp techniques were used. Small mouse renal arteries were placed in the myograph chamber, and after the optimal concentration for the vasodilator effect of nebivolol was established (50 microM), the arteries were further investigated to assess the potential contribution of nitric oxide (NO) and of Ca2+ ions to the nebivolol-induced effect, by exposing the arteries to the specific inhibitors such as N(G)-nitro-L-arginine methylester (L-NAME, 100 microM), ethylenglycol-bis-(beta-amino-ethylen ester) N,N'-tetraacetic acid (EGTA, 4 microM) and thapsigargin (1 microM). The expression of NO synthase was evaluated by the Western-blot technique. Using myograph and patch-clamp techniques applied on intact renal artery, we investigated the role of beta2-adrenoceptors, of myoendothelial junctions and of Ca(2+)-activated K+ channels in the vasodilatory effects of nebivolol, using 100 microM butoxamine, 40 microM 18 beta-glycyrrhetinic acid, 1 mM tetraethylammonium, and 100 nM iberiotoxin, respectively. The results showed that the cellular mechanisms of the vasodilator effect of nebivolol on the renal artery entail (i) activation of the endothelial beta2-adrenoceptor, (ii) participation of [Ca2+]i, (iii) increase in NO and eNOS, and (iv) activation of Ca(2+)-activated K+ channels. The cellular mechanisms underlying vasodilator effect of nebivolol on the artery explain the favorable effect of this drug in hypertension.

[Cardiorenal pathology in diabetes mellitus type 1: mechanisms of development and medical correction]

AIM

To elicit the role of endothelial dysfunction in development of cardiorenal syndrome in patients with diabetes mellitus type 1 (DM1) with diabetic nephropathy (DN) and to evaluate the efficacy of endotheliotropic drugs: nebivolol (a selective beta-blocker) and enalapril (ACE inhibitor).

MATERIAL AND METHODS

The trial enrolled 60 patients with DM1: 15 patients with normoalbuminuria (NAU), 15 patients with microalbuminuria (MAU), 15 patients with proteinuria (PU) and 15 with chronic renal failure (CRF). The control group consisted of 15 healthy volunteers matched by sex and age. All the patients were examined for endothelium-dependent dilation of the brachial artery (by duplex scanning in the test with reactive hyperemia), serum markers of endothelial dysfunction (endothelin-1--ET-1), Willebrand factor (WF), inflammation markers (C-reactive protein-CRP), incidence rate of ischemic heart disease (IHD). 24-h arterial pressure monitoring and echocardiography were also made. For 12 weeks the patients were given nebivolol monotherapy in a dose 5 mg/day or enalapril monotherapy in a dose 10 mg/day. The effects of these drugs on urinary excretion of albumin and protein, arterial pressure, circadial rhythm of arterial pressure and endothelial dysfunction were studied.

RESULTS

In DM1 patients DN advances with an increase in development of IHD: in MAU--by 13%, PU--by 33%, CRF--53%. Concentric hypertrophy and left ventricular remodeling were registered in 33, 40 and 60% of cases, respectively. A circadian rhythm disturbance correlated with DN severity. DN progression was associated with increasing endothelial dysfunction. It is shown that nebivolol and enalapril correct endothelial dysfunction, have comparable antiproteinuric and antihypertensive actions at different stages of nephropathy.

CONCLUSION

A close correlation was found between DN progression and development of cardiovascular pathology in DM1 patients. This serves the basis of cardiorenal syndrome. These two pathologies are associated with vascular endothelial dysfunction which leads to disorders in vascular tonicity regulation.

[Antiischemic and metabolic effects of nebivolol and metaprolol CR/XL (betalok ZOK) in patients with postinfarction heart dysfunction]

The purpose of the study was to evaluate anti-ischemic and metabolic effects of the cardioselective beta-adrenoblockers nebivolol and retarded metoprolol-metaprolol CR/XL (betalok ZOK) in patients with postinfarction heart dysfunction, associated with type II diabetes mellitus (DM). 40 patients with coronary heart disease (CHD), functional class (FC) II-III exertional angina, postinfarction left ventricular (LV) dysfunction, and NYHA FC II heart failure, associated with type II DM, were randomized into 2 groups. The 20 patients of the 1st group were administered nebivolol in a dose of 1.25 to 5 mg per day, the 20 patients of the 2nd group - betalok ZOK in a dose of 12.5 to 100 mg per day. The course therapy lasted 8 weeks. The effects of the treatment were evaluated using paired veloergometry, echoCG, and lipid spectrum analysis. The study found that nebivolol in a mean dose of 4.2 +/- 0.3 mg per day and betalok ZOK in a dose of 46.5 +/- 6.2 mg per day reduced the frequency and severety of angina attacks (by 73.8% and 67.8%, respectively) and daily nitroglycerine uptake (by 78.6% and 69.1%, respectively), and increased activity tolerance (by 7.9% and 25.3%, respectively). None of the preparations displayed any adverse effects on carbohydrate exchange and blood lipid spectrum. Nebivolol, unlike betalok ZOK, significantly (p = 0.02) reduced triglyceride blood level by 29%. Thus, the new generation cardioselective beta1-adrenoblockers nebivolol and metoprolol CR/XL (betalok ZOK) provide anti-ischemic and metabolic effects in patients with CHD and postinfarction LV dysfunction, associated with type 2 diabetes mellitus. Nebivolol is preferable as far as blood lipid spectrum is concerned.