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

Role of nebivolol in the control and management of central aortic blood pressure in hypertensive patients

Measurement of blood pressure (BP) using a brachial cuff sphygmomanometer is universally accepted for the diagnosis of hypertension and prediction of cardiovascular diseases. However, brachial systolic BP does not represent actual systolic BP in the central arteries which encounter cardiac load directly. Due to wave amplification from central to peripheral arteries, a significant difference exists between the two. Central BP measurements also account for arterial stiffness, vessel branching and vascular mechanics, unlike brachial BP. Emerging data suggests that hypertension can be diagnosed more accurately by central pressure indices as compared to brachial BP. Various non-invasive techniques are now available to measure central BP indices owing to recent technological advances. Recently, it has been reported that different classes of anti-hypertensive drugs display differential effects on brachial and central BPs. Nebivolol is a cardio-selective beta-blocker which targets central systolic BP and reduces it significantly along with brachial BP. In this article, we will review the current literature to evaluate the role of central BP to diagnose hypertension in detail. We will also assess the clinical evidence to evaluate the role of nebivolol in the management of elevated central systolic BP. Central BP indices offer better estimation of BP in central arteries and should be considered in routine clinical practice. Nebivolol has shown significant reduction in aortic pressure and wave reflection and improvements in endothelial dysfunction and arterial stiffness in hypertensive patients.

Nebivolol Effects on Nitric Oxide Levels, Blood Pressure, and Renal Function in Kidney Transplant Patients

In hypertensive kidney transplant recipients, the effects of nebivolol vs metoprolol on nitric oxide (NO) blood level, estimated glomerular filtration rate (eGFR), and blood pressure (BP) have not been previously reported. In a 12-month prospective, randomized, open-label, active-comparator trial, hypertensive kidney transplant recipients were treated with nebivolol (n=15) or metoprolol (n=15). Twenty-nine patients (nebivolol [n=14], metoprolol [n=15]) completed the trial. The primary endpoint was change in blood NO level after 12 months of treatment. Secondary endpoints were changes in eGFR, BP, and number of antihypertensive drug classes used. After 12 months of treatment, least squares mean change in plasma NO level in the nebivolol kidney transplant recipient group younger than 50 years was higher by 68.19% (99.17% confidence interval [CI], 13.02-123.36), 69.54% (99.17% CI, 12.71-126.37), and 66.80% (99.17% CI, 12.95-120.64) compared with the metoprolol group younger than 50 years, the metoprolol group 50 years and older, and the nebivolol group 50 years and older, respectively. The baseline to month 12 change in mean arterial BP, eGFR, and number of antihypertensive drug classes used was not significantly different between the treatment groups. In hypertensive kidney transplant recipients, nebivolol use in patients younger than 50 years increased blood NO.

Recent advances in the treatment of renal diseases with nebivolol: A literature review

Reactive oxygen species play an important role in both acute and chronic kidney diseases. Chronic kidney disease is associated with various consequences to the cardiovascular system and metabolic profiles. Nebivolol, a highly cardioselective third-generation β-blocker, has nitric oxide (NO) induced vasodilation and antioxidant properties. Nebivolol affects the endothelial NO pathway in two complementary ways: it increases endothelial mediated NO expression and has antioxidant action, which leads to a decrease in degradation. Central blood pressure can be effectively lowered by nebivolol in the prehypertension phase. Clinically nebivolol's ability to modulate endothelial dysfunction may offer additional vascular protection in treating hypertension. As well, pre-treatment with 5mg nebivolol every 24 hours for 4 days is protective against nephrotoxic effects of contrast media. The aim of this study is to review the current literature on the efficacy and safety of nebivolol in the treatment of various states of renal diseases.

Impact of Antihypertensive Agents on Central Systolic Blood Pressure and Augmentation Index: A Meta-Analysis

BACKGROUND

New evidence suggests that central systolic blood pressure (cSBP) and augmentation index (AI) are superior predictors of adverse cardiovascular outcomes compared to peripheral systolic BP (pSBP). We performed a meta-analysis assessing the impact of antihypertensives on cSBP and AI.

METHODS

PubMed, Cochrane Library, and CINAHL were searched until September 2014 to identify eligible articles. A DerSimonian and Laird random-effects model was used to calculate the weighted mean difference (WMD) and its 95% confidence interval (CI). Fifty-two and 58 studies incorporating 4,381 and 3,716 unique subjects were included for cSBP and AI analysis, respectively.

RESULTS

Overall, antihypertensives reduced pSBP more than cSBP (WMD 2.52 mm Hg, 95% CI 1.35 to 3.69; I (2) = 21.9%). β-Blockers (BBs) posed a significantly greater reduction in pSBP as compared to cSBP (WMD 5.19 mm Hg, 95% CI 3.21 to 7.18). α-Blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors and nicorandil reduced cSBP and pSBP in a similar manner. The overall reduction in AI from baseline was 3.09% (95% CI 2.28 to 3.90; I (2) = 84.5%). A significant reduction in AI was seen with angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors, BBs, α-blockers (ABs), nicorandil, and moxonidine reduced AI nonsignificantly.

CONCLUSIONS

BBs are not as beneficial as the other antihypertensives in reducing cSBP and AI.

Effects of β-Blockers With and Without Vasodilating Properties on Central Blood Pressure

β-Blockers are less effective than other antihypertensive drug classes in reducing central systolic blood pressure (cSBP) as compared with peripheral SBP (pSBP). Whether this effect is less pronounced with vasodilating β-blockers (VBB) when compared with nonvasodilating β-blockers (NVBB) remains unsettled. We conducted a systematic review and meta-analysis of randomized trials exploring the effects of β-blockers on both pSBP and cSBP in hypertension. We selected 20 studies, for a total of 32 treatment arms (n=21 for NVBB, n=11 for VBB) and 1263 participants (n=962 for NVBB, n=301 for VBB). pSBP decreased from 150 to 133 mm Hg for NVBB and from 145 to 134 mm Hg for VBB. cSBP decreased from 137 to 126 mm Hg for NVBB and from 132 to 123 mm Hg for VBB. SBP amplification (pSBP–cSBP) decreased significantly under VBB (−5.6 mm Hg; 95% confidence interval, −7.8, −3.4 mm Hg), but not under NVBB (−1.1 mm Hg; 95% confidence interval, −3.4, +1.2 mm Hg; P <0.01 versus NVBB). There was high heterogeneity both within and between β-blockers subclasses. In a meta-regression model, the weighted difference in treatment-induced changes in SBP amplification between NVBB and VBB lost its significance after adjustment for mean age and baseline pSBP and heart rate (−2.9±2.3 mm Hg; P =0.22) and was almost abolished after adjustment for treatment-induced heart rate changes (−0.1±0.5 mm Hg; P =0.78). In conclusion, NVBBs, but not VBBs, determine a lower reduction in cSBP than in pSBP. However, the difference in treatment-induced SBP amplification changes between NVBB and VBB is nearly abolished after accounting for differences in heart rate changes.

The Role of Central Nervous System Mechanisms in Resistant Hypertension

Arterial hypertension remains a primary global health problem with significant impact on cardiovascular morbidity and mortality. The low rate of hypertension control and failure to achieve target blood pressure levels particularly among high-risk patients with resistant hypertension has triggered renewed interest in unravelling the underlying mechanisms to implement therapeutic approaches for better patient management. Here, we summarize the crucial role of neurogenic mechanisms in drug-resistant hypertension, with a specific focus on central control of blood pressure, the factors involved in central integration of afferent signalling to increase sympathetic drive in resistant hypertension, and briefly review recently introduced interventional strategies distinctively targeting sympathetic activation.

Preventing the progression of prehypertension to hypertension: role of antihypertensives

Recent guidelines for the diagnosis and management of hypertension reversed the historical trend to recommend lower blood pressure (BP) thresholds to diagnose hypertension in high-risk individuals, such as patients with diabetes and elderly patients. The decision to raise the BP thresholds for diagnosis of hypertension in patients with diabetes was mostly based on the findings of the ACCORD trial. Nonetheless, the results of the ACCORD trial are within the predicted benefit to prevent coronary artery disease and stroke by meta-analysis of randomized controlled trials (RCT), particularly in regard to the prevention of stroke. The Eighth Joint National Committee (JNC 8) did not address prehypertension. There are many RCT done in individuals with prehypertension and concomitant cardiovascular disease showing the benefit of treatment of these patients. Trials exploring the efficacy of interventions to prevent cardiovascular disease in individuals with prehypertension free of cardiovascular disease would be hardly feasible in face of the low absolute risk of these individuals. Considering the risks of prehypertension for cardiovascular disease and the fast progression to hypertension of a large proportion of individuals with prehypertension, it is worth to consider drug treatment for individuals with prehypertension. RCT showed that the progression to hypertension can be partially halted by BP-lowering agents. These and ongoing clinical trials are herein revised. Prehypertension may be a window of opportunity to prevent hypertension and its cardiovascular consequences.

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 β1 -antagonist with β3 -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.

The current status of beta blockers' use in the management of hypertension

The invention of beta (β)-blockers culminated in a new era in the treatment of cardiovascular diseases (CD), and changed the course of pharmacology research for years to come. Since the introduction of propranolol into clinical practice in 1964, β-blockers enjoyed a special place in the clinicians' armamentarium against CDs, especially for patients with ischemic heart diseases, and are still one of the most extensively used therapeutic drugs in both cardiac and non-cardiac ailments. Current uses of β-blockers in CDs include ischemic heart diseases, hypertension, cardiac arrhythmias, and heart failure. Other substantial non-cardiac uses include glaucoma, migraine, situational anxiety, benign essential tremors, and cardiac symptoms of thyrotoxicosis. This review covers some of the evolutionary changes of clinical uses of β-blockers, the rationale for their use, some recent controversies surrounding their use for treatment of hypertension, and advantages of newer additions to the group.