Analysis of decreases in systemic arterial pressure and heart rate in response to the hydrogen sulfide donor sodium sulfide.

The actions of hydrogen sulfide (H2S) on the heart and vasculature have been extensively reported. However, the mechanisms underlying the effects of H2S are unclear in the anesthetized rat. The objective of the present study was to investigate the effect of H2S on the electrocardiogram and examine the relationship between H2S-induced changes in heart rate (HR), mean arterial pressure (MAP), and respiratory function. Intravenous administration of the H2S donor Na2S in the anesthetized Sprague-Dawley rat decreased MAP and HR and produced changes in respiratory function. The administration of Na2S significantly increased the RR interval at some doses but had no effect on PR or corrected QT(n)-B intervals. In experiments where respiration was maintained with a mechanical ventilator, we observed that Na2S-induced decreases in MAP and HR were independent of respiration. In experiments where respiration was maintained by mechanical ventilation and HR was maintained by cardiac pacing, Na2S-induced changes in MAP were not significantly altered, whereas changes in HR were abolished. Coadministration of glybenclamide significantly increased MAP and HR responses at some doses, but methylene blue, diltiazem, and ivabradine had no significant effect compared with control. The decreases in MAP and HR in response to Na2S could be dissociated and were independent of changes in respiratory function, ATP-sensitive K+ channels, methylene blue-sensitive mechanism involving L-type voltage-sensitive Ca2+ channels, or hyperpolarization-activated cyclic nucleotide-gated channels. Cardiovascular responses observed in spontaneously hypertensive rats were more robust than those in Sprague-Dawley rats.NEW & NOTEWORTHY H2S is a gasotransmitter capable of producing a decrease in mean arterial pressure and heart rate. The hypotensive and bradycardic effects of H2S can be dissociated, as shown with cardiac pacing experiments. Responses were not blocked by diltiazem, ivabradine, methylene blue, or glybenclamide.

Rationale for nebivolol/valsartan combination for hypertension: review of preclinical and clinical data.

: To treat hypertension, combining two or more antihypertensive drugs from different classes is often necessary. ß-Blockers and renin-angiotensin-aldosterone system inhibitors, when combined, have been deemed 'less effective' based on partially overlapping mechanisms of action and limited evidence. Recently, the single-pill combination (SPC) of nebivolol (Neb) 5 mg - a vasodilatory ß1-selective antagonist/ß3 agonist - and valsartan 80 mg, an angiotensin II receptor blocker, was US Food and Drug Administration-approved for hypertension. Pharmacological profiles of Neb and valsartan, alone and combined, are well characterized. In addition, a large 8-week randomized trial in stages I-II hypertensive patients (N = 4161) demonstrated greater blood pressure-reducing efficacy for Neb/valsartan SPCs than component monotherapies with comparable tolerability. In a biomarkers substudy (N = 805), Neb/valsartan SPCs prevented valsartan-induced increases in plasma renin, and a greater reduction in plasma aldosterone was observed with the highest SPC dose vs. valsartan 320 mg/day. This review summarizes preclinical and clinical evidence supporting Neb/valsartan as an efficacious and well tolerated combination treatment for hypertension.

Efficacy of nebivolol-valsartan single-pill combination in obese and nonobese patients with hypertension.

Antihypertensive efficacy of single-pill combinations (SPCs) consisting of a ß1 -selective adrenergic blocker with vasodilatory properties via ß3 -agonism (nebivolol) and an angiotensin II receptor blocker (valsartan) was demonstrated in an 8-week phase 3 trial (NCT01508026). In this post hoc analysis, seated blood pressure, heart rate, 24-hour ambulatory blood pressure monitoring, plasma aldosterone, estimated glomerular filtration rate, and safety measures were assessed in obese (body mass index >32 kg/m2 ; n=1823) and nonobese (body mass index <27 kg/m2 ; n=847) adults with hypertension (stage I or II) treated with nebivolol-valsartan SPCs, nebivolol or valsartan monotherapy, or placebo. At week 8, reductions from baseline in blood pressure and ambulatory blood pressure monitoring were greater with SPCs and most nebivolol and valsartan monotherapy doses vs placebo regardless of obesity status. Aldosterone declined with all active treatments and estimated glomerular filtration rate remained steady. The nebivolol-valsartan 5/80 mg/d SPC was efficacious regardless of degree of obesity.

Methodological evaluation of the noninvasive estimation of central systolic blood pressure in nontreated patients: the Bogalusa Heart Study.

OBJECTIVES: This study sought to compare the estimation of central systolic blood pressure (cSBP) obtained by two different noninvasive devices, in addition to its comparisons with measured peripheral systolic blood pressure (pSBP), in a biracial (Black/White) community-based cohort. PARTICIPANTS AND METHODS: Estimations of cSBP by applanation tonometry were obtained in 586 participants of the Bogalusa Heart Study (mean age: 43.5 years; 69% White, 54% women) using two different commonly used instruments: Omron HEM-9000AI and SphygmoCor CPV. pSBP was measured using a standard auscultatory technique. RESULTS: The estimation of cSBP by the Omron device was higher than that of the SphygmoCor device (124.2±17.1 vs. 111.4±15.2 mmHg, P<0.001). Moreover, cSBP by Omron was significantly higher than peripheral blood pressure (124.2±17.1 vs. 119.4±15.6 mmHg, P<0.001), whereas cSBP by SphygmoCor was significantly lower than pSBP (111.4±15.2 vs. 119.4±15.6 mmHg, P<0.001). Similar results were observed in race-specific and sex-specific analyses. CONCLUSION: These findings support the hypothesis that notable differences exist in the estimation of cSBP provided by the instruments utilized in this study. Further standardization studies are required to establish the most appropriate noninvasive estimation of cSBP before this parameter may be considered in the assessment, prediction, and prevention of cardio-metabolic risk and overt cardiovascular disease in clinical practice.

Nebivolol has a beneficial effect in monocrotaline-induced pulmonary hypertension.

Pulmonary hypertension is a rare disorder that, without treatment, is progressive and fatal within 3-4 years. Current treatment involves a diverse group of drugs that target the pulmonary vascular bed. In addition, strategies that increase nitric oxide (NO) formation have a beneficial effect in rodents and patients. Nebivolol, a selective ß1 adrenergic receptor-blocking agent reported to increase NO production and stimulate ß3 receptors, has vasodilator properties suggesting that it may be beneficial in the treatment of pulmonary hypertension. The present study was undertaken to determine whether nebivolol has a beneficial effect in monocrotaline-induced (60 mg/kg) pulmonary hypertension in the rat. These results show that nebivolol treatment (10 mg/kg, once or twice daily) attenuates pulmonary hypertension, reduces right ventricular hypertrophy, and improves pulmonary artery remodeling in monocrotaline-induced pulmonary hypertension. This study demonstrates the presence of ß3 adrenergic receptor immunoreactivity in pulmonary arteries and airways and that nebivolol has pulmonary vasodilator activity. Studies with ß3 receptor agonists (mirabegron, BRL 37344) and antagonists suggest that ß3 receptor-mediated decreases in systemic arterial pressure occur independent of NO release. Our results suggest that nebivolol, a selective vasodilating ß1 receptor antagonist that stimulates ß3 adrenergic receptors and induces vasodilation by increasing NO production, may be beneficial in treating pulmonary hypertensive disorders.

Fixed-dose combination therapy of nebivolol and valsartan for the treatment of hypertension.

Recent large clinical trials have refuted earlier suggestions from the Joint National Committee 8 committee that less aggressive targets for blood pressure control were all that could be justified in most hypertensive patients. It now does appear that in fact "lower is better," with blood pressure targets < 120/80 mm Hg appropriate for many hypertensive patients. Two drug combinations are often indicated as initial therapy if a 20/10 mm Hg or greater blood pressure reduction is necessary to reach target. Combinations consisting of ß-blockers and renin-angiotensin-aldosterone system inhibitors have previously been deemed "less effective," based on partially overlapping mechanisms of action and limited clinical trial evidence. Nebivolol is a vasodilating ß1-selective blocker and ß3- adrenoceptor agonist; ß3-adrenoceptor activation increases nitric oxide concentrations and thus explains the vasodilatory effect. A recent 8-week randomized trial (N=4,161) in individuals with stage 1-2 hypertension demonstrated that single-pill fixed dose combinations (FDC) of nebivolol and valsartan, an angiotensin II subtype 1 receptor blocker, were more effective in reducing blood pressure than the corresponding monotherapies, with comparable tolerability. In addition, an ABPM-biomarkers substudy from that trial (n=805) demonstrated that the FDC prevented a valsartan-induced increase in plasma renin activity, and that the nebivolol/valsartan 20/320 mg/day dose reduced plasma aldosterone concentration significantly more than valsartan 320 mg/day. This article will describe the properties of nebivolol that make it unique and separate it from other ß-blockers, and will further support the pharmacological advantages of this particular combination.

Prehypertension: Defining the Transitional Phenotype.

More than a simple "transitional stage" defined by covenanted cut points of systolic pressure from 120 to 139 mm of mercury (mm Hg) or a diastolic pressure from 80 to 89 mm Hg, prehypertension should be referred to as a categorical term that defines a specific phenotype in the progression from the "absence of disease" to clinically overt disease. While the currently utilized definition of prehypertension stresses the use of blood pressure cut points to establish the diagnosis, it is of relevance to direct our attention to the structural and functional hemodynamic alterations that occur in response to the two cardinal abnormalities in the development of prehypertension and hypertension: autonomic dysfunction and arterial remodeling. Our current review addresses these aspects of the pathophysiology or prehypertension on its progression to hypertension and suggests a new approach to its classification.

Correlations of plasma renin activity and aldosterone concentration with ambulatory blood pressure responses to nebivolol and valsartan, alone and in combination, in hypertension.

After demonstration of the antihypertensive efficacy of the combination of the beta-blocker nebivolol and the angiotensin receptor blocker valsartan in an 8-week, randomized, placebo-controlled trial (N = 4161), we now report the effects of this treatment on the renin-angiotensin-aldosterone system in a substudy (n = 805). Plasma renin activity increased with valsartan (54%-73%) and decreased with nebivolol (51%-65%) and the combination treatment (17%-39%). Plasma aldosterone decreased with individual treatments (valsartan, 11%-22%; nebivolol, 20%-26%), with the largest reduction (35%) observed with maximum combination dose (20 mg nebivolol/320 mg valsartan). Baseline ln(plasma renin activity) correlated with the 8-week reductions in 24-hour systolic and diastolic BP following treatments with the combination (all doses combined, P = .003 and P < .001) and nebivolol (both, P < .001), but not with valsartan. Baseline ln(aldosterone) correlated with 24-hour systolic and diastolic BP reductions following combination treatment only (P < .001 and P = .005). The implications of the renin-angiotensin-aldosterone system effects of this beta blocker-angiotensin receptor blocker combination should be explored further.

Nebivolol and valsartan as a fixed-dose combination for the treatment of hypertension.

INTRODUCTION: The fixed-dose combination of nebivolol and valsartan drug has been clinically evaluated and demonstrated to represent a unique combination of nebivolol, a selective ß1-adrenoceptor antagonist and a ß3-adrenoceptor agonist; ß3 receptor activation increases endothelial nitric oxide and produces vasodilation. Valsartan is highly selective angiotensin AT1 receptor blocker and exerts its major pharmacological effect by decreasing angiotensin II-induced vasoconstriction and production of aldosterone. The addition of nebivolol counteracts the effects of increased angiotensin II concentrations resulting from potent AT1 blockade. This review describes a recently completed trial establishing the efficacy of the nebivolol/valsartan combination. AREAS COVERED: This review provides a literature search of pertinent pharmacological and clinical data that describes the mechanisms of both drugs individually and the results of a clinical trial comparing fixed-dose combinations of nebivolol with valsartan as compared with each drug as monotherapy. EXPERT OPINION: Fixed-dose combination drugs are intended to improve patient compliance and reduce drug costs, as well as to reduce long-term cardiovascular event rates and block counter-regulatory effects due to monotherapy. The vast majority of hypertensive patients will require at least two medications. We believe that the clinical evidence suggests that the combination of nebivolol with valsartan offers a definite clinical benefit, combining ß1-adrenoceptor and angiotensin AT1 receptor blockade with ß3 receptor activation and resultant increase in nitric oxide and vasodilation.

Digital plethysmography and arginine metabolism in prehypertension: effect of nebivolol therapy.

Prehypertension is an important phenotype for cardiovascular risk and development of established hypertension. To better understand the early circulatory changes in this group, the authors studied 34 patients with prehypertension (blood pressure 120-139/80-89 mm Hg) using digital plethysmography for measurement of blood flow and reactive hyperemic index (RHI). Arterial augmentation index (AI) was also measured. Because prehypertension is associated with endothelial dysfunction and decreased availability of nitric oxide (NO), indices of arginine metabolism (l-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine, and l-citrulline) were measured. Nebivolol (5 mg/d), a vasodilating ß1 -antagonist with ß3 -agonist activity, was studied in a double-blind fashion for 8 weeks. Nebivolol increases the bioavailability of NO. Prehypertension was associated with normal RHI and baseline digital blood flow. AI was abnormal and associated with diastolic blood pressure. ADMA concentration was increased at baseline. After 8 weeks of nebivolol therapy, RHI, ADMA, symmetric dimethylarginine, and AI showed no significant change, but digital blood flow and l-citrulline levels were significantly increased. Prehypertension is associated with increased ADMA and evidence of increased arterial stiffness and preserved RHI. Nebivolol therapy is associated with digital vasodilation and increased NO production, as depicted by increased levels of l-citruline and mean digital blood flow.

Long-term safety of nebivolol and valsartan combination therapy in patients with hypertension: an open-label, single-arm, multicenter study.

Long-term safety of a free-tablet combination of nebivolol and valsartan was assessed in a Phase III, open-label trial (NCT01415505). Adults with hypertension entered a 4-week placebo run-in phase, followed by a 52-week treatment phase. Initial dosage (Neb/Val 5/160 mg/d) was titrated up to 20/320 mg/d to achieve blood pressure (BP) goal (JNC7 criteria), with the addition of hydrochlorothiazide (up to 25 mg/d) if needed. Safety and tolerability parameters included adverse events. Efficacy assessments included baseline-to-endpoint change in diastolic BP and systolic BP and the percentage of patients who achieved BP goal. All analyses were performed using descriptive statistics. Study completion rate was 60.4% (489/810). The most frequent reason for discontinuation was insufficient therapeutic response (8.4%). Adverse events were experienced by 59.2% of patients, with the most common being headache (5.7%), nasopharyngitis (5.0%), and upper respiratory tract infection (4.6%). Three (0.4%) deaths occurred during the study; none was considered related to study medication. Mean ± standard deviation changes from baseline at week 52 (observed cases) were -25.5 ± 15.9 mm Hg (systolic BP) and -19.0 ± 8.7 mm Hg (diastolic BP). A total of 75.7% nebivolol/valsartan-treated and 57.8% nebivolol/valsartan/hydrochlorothiazide-treated completers achieved BP goal. Long-term treatment with nebivolol and valsartan in adults with hypertension was safe and well-tolerated.

Efficacy and safety of nebivolol and valsartan as fixed-dose combination in hypertension: a randomised, multicentre study.

BACKGROUND: The fixed-dose combination of any two antihypertensive drugs from different drug classes is typically more effective in reducing blood pressure than a dose increase of component monotherapy. We assessed the efficacy and safety of a fixed-dose combination of a vasodilating ß blocker (nebivolol) and an angiotensin II receptor blocker (valsartan) in adults with hypertension. METHODS: We did an 8-week, phase 3, multicentre, randomised, double-blind, placebo-controlled, parallel-group trial at 401 US sites. Participants (age ≥18 years) with hypertension but with blood pressure less than 180/110 mm Hg were randomly assigned (2:2:2:2:2:2:2:1) by a 24-h interactive web response system in blocks of 15 to 4 weeks of double-blind treatment with nebivolol and valsartan fixed-dose combination (5 and 80 mg/day, 5 and 160 mg/day, or 10 and 160 mg/day), nebivolol (5 mg/day or 20 mg/day), valsartan (80 mg/day or 160 mg/day), or placebo. Doses were doubled in weeks 5-8; results are reported according to the final dose. Participants and research staff were masked to treatment allocation. The primary and key secondary endpoints were changes from baseline to week 8 in diastolic and systolic blood pressure, respectively. The primary statistical comparison was between the highest fixed-dose combination dose and the highest monotherapy doses; lower doses were then compared if this comparison was positive (Hochberg method for multiple testing). Efficacy analyses were by intention to treat. Safety assessments included monitoring of adverse events. Continuous efficacy parameters were analysed using an ANCOVA model; binary outcomes were analysed using a logistic regression model. This study is registered with ClinicalTrials.gov, NCT01508026. FINDINGS: Between Jan 6, 2012, and March 15, 2013, 4161 patients were randomly assigned (277 to placebo and 554-555 to each active comparator group), 4118 of whom were included in the primary analysis. At week 8, the fixed-dose combination 20 and 320 mg/day group had significantly greater reductions in diastolic blood pressure from baseline than both nebivolol 40 mg/day (least-squares mean difference -1·2 mm Hg, 95% CI -2·3 to -0·1; p=0·030) and valsartan 320 mg/day (-4·4 mm Hg, -5·4 to -3·3; p<0·0001); all other comparisons were also significant, favouring the fixed-dose combinations (all p<0·0001). All systolic blood pressure comparisons were also significant (all p<0·01). At least one treatment-emergent adverse event was experienced by 30-36% of participants in each group. INTERPRETATION: Nebivolol and valsartan fixed-dose combination is an effective and well-tolerated treatment option for patients with hypertension. FUNDING: Forest Research Institute.

Incidence of atrial fibrillation in a population with impaired glucose tolerance: the contribution of glucose metabolism and other risk factors. A post hoc analysis of the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research trial.

BACKGROUND: The role of dysglycemia as an additional risk factor for atrial fibrillation (AF) is controversial. Therefore, it was of interest to assess risk factors for incident AF in a large, representative population of patients with cardiovascular risk factors and impaired glucose tolerance but not overt diabetes in NAVIGATOR. METHODS: Predictors of incident AF were analyzed in 8,943 patients without AF at baseline by Cox proportional hazards regression. Study treatments (valsartan vs no valsartan and nateglinide vs no nateglinide) and the time-dependent covariate for progression to type 2 diabetes mellitus were added separately to the model. RESULTS: The median age of the 8,943 patients included in the present analysis of the NAVIGATOR trial was 63 years. Half of those patients were men, 6,922 (77.4%) had a history of hypertension, and 255 (2.9%) had heart failure. The median glycated hemoglobin was 6%. During the study, 613 of the 8,943 patients without AF at baseline presented with at least 1 episode of AF (6.9% 5-year incidence). Besides established predictors of incident AF, a 1 mmol/L increment of baseline fasting glucose, but not progression to diabetes, was found to be associated with a 33% increased risk of incident AF. Neither valsartan nor nateglinide affected AF incidence. CONCLUSIONS: In a trial population with impaired glucose tolerance, fasting plasma glucose and well-known risk factors (age, hypertension, and elevated body weight), but not progression to diabetes, predict risk of AF.