Carvedilol improves endothelium-dependent vasodilation in patients with dilated cardiomyopathy

Endothelial Function Is Preserved in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy

Heart failure (HF) is associated with endothelial dysfunction. Vascular function per se plays an important role in cardiac function, whether it is a cause or consequence. However, there is no information on vascular function in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). The purpose of this study was to evaluate vascular function in patients with ATTRwt-CM. We measured flow-mediated vasodilation (FMD) as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function and brachial artery intima-media thickness (bIMT) and brachial-ankle pulse wave velocity (baPWV) as indices of arterial stiffness in 22 patients with ATTRwt-CM and in 22 one-by-one matched control patients using vascular function confounding factors. FMD was significantly greater in patients with ATTRwt-CM than in the controls (5.4 ± 3.4% versus 3.5 ± 2.4%, p = 0.038) and the N-terminal pro-brain natriuretic peptide (NT-proBNP) level was significantly greater in patients with ATTRwt-CM than in the controls (2202 ± 1478 versus 470 ± 677 pg/mL, p < 0.001). There were no significant differences in NID, bIMT or baPWV between the two groups. There was a significant relationship between NT-proBNP and FMD in patients with ATTRwt-CM (r = 0.485, p = 0.022). NT-proBNP showed no significant relationships with NID, bIMT or baPWV. Conclusions: Endothelial function was preserved in patients with ATTRwt-CM. Patients with ATTRwt-CM may have compensatory effects with respect to endothelial function through elevation of BNP.

Cardiovascular risk in patients receiving antihypertensive drug treatment from the perspective of endothelial function

Blood-pressure-lowering therapy with antihypertensive drugs can reduce the risk of cardiovascular morbidity and mortality in patients with hypertension. However, patients treated with antihypertensive drugs generally have a worse prognosis than untreated individuals. Consistent with the results obtained from epidemiological studies, a clinical study showed that endothelial function was impaired more in treated patients with hypertension than in untreated individuals with the same blood pressure level, suggesting that blood-pressure-lowering therapy with currently available antihypertensive drugs cannot restore endothelial function to the level of that in untreated individuals. Several mechanisms of endothelial dysfunction in treated patients are postulated: irreversible damage to the endothelium caused by higher cumulative elevated blood pressure exposure over time; the persistence of the primary causes of hypertension even after the initiation of antihypertensive drug treatment, including an activated renin-angiotensin-aldosterone system, oxidative stress, and inflammation; and higher global cardiovascular risk related not only to conventional cardiovascular risk factors but also to undetectable nonconventional risk factors. Lifestyle modifications/nonpharmacological interventions should be strongly recommended for both untreated and treated individuals with hypertension. Lifestyle modifications/nonpharmacological interventions may directly correct the primary causes of hypertension, which can improve endothelial function and consequently reduce cardiovascular risk regardless of the use or nonuse of antihypertensive drugs.

Vascular Dysfunction Predicts Future Deterioration of Left Ventricular Ejection Fraction in Patients with Heart Failure with Mildly Reduced Ejection Fraction

The purpose of this study was to evaluate whether heart failure with mildly reduced ejection fraction (HFmrEF) is associated with vascular dysfunction and whether vascular function predicts future deterioration of LVEF in patients with HFmrEF. We evaluated endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID) in 69 patients with HFmrEF and 426 patients without HF and evaluated the future deterioration of LVEF, defined as a decrease in LVEF to <40%, in 39 patients with HFmrEF for up to 3 years. Both FMD and NID were significantly lower in patients with HFmrEF than in patients without HF. We categorized patients into two groups based on low tertiles of NID: a low group (NID of <7.0%) and an intermediate and high group (NID of ≥7.0%). There were significant differences between the Kaplan–Meier curves for the deterioration of LVEF in the two groups (p < 0.01). Multivariate Cox proportional hazard analysis revealed that NID of <7.0% was an independent predictor of future deterioration of LVEF in patients with HFmrEF. Both endothelial function and vascular smooth muscle function are impaired in patients with HFmrEF compared with those in patients without HF. In addition, low NID of <7.0% predicts future deterioration of LVEF.

Vasodilation Elicited by Isoxsuprine, Identified by High-Throughput Virtual Screening of Compound Libraries, Involves Activation of the NO/cGMP and H₂S/KATP Pathways and Blockade of α₁-Adrenoceptors and Calcium Channels

Recently, our research group demonstrated that uvaol and ursolic acid increase NO and H₂S production in aortic tissue. Molecular docking studies showed that both compounds bind with high affinity to endothelial NO synthase (eNOS) and cystathionine gamma-lyase (CSE). The aim of this study was to identify hits with high binding affinity for the triterpene binding-allosteric sites of eNOS and CSE and to evaluate their vasodilator effect. Additionally, the mechanism of action of the most potent compound was explored. A high-throughput virtual screening (HTVS) of 107,373 compounds, obtained from four ZINC database libraries, was performed employing the crystallographic structures of eNOS and CSE. Among the nine top-scoring ligands, isoxsuprine showed the most potent vasodilator effect. Pharmacological evaluation, employing the rat aorta model, indicated that the vasodilation produced by this compound involved activation of the NO/cGMP and H₂S/K_ATP signaling pathways and blockade of α₁-adrenoceptors and L-type voltage-dependent Ca²⁺ channels. Incubation of aorta homogenates in the presence of isoxsuprine caused 2-fold greater levels of H₂S, which supported our preliminary in silico data. This study provides evidence to propose that the vasodilator effect of isoxsuprine involves various mechanisms, which highlights its potential to treat a wide variety of cardiovascular diseases.

Why names matter for women: MINOCA/INOCA (myocardial infarction/ischemia and no obstructive coronary artery disease)

The syndromes of myocardial infarction/myocardial ischemia with No Obstructive Coronary Artery Disease (MINOCA/INOCA) are increasingly evident. A majority of these patients have coronary microvascular dysfunction. These patients have elevated risk for a cardiovascular event (including acute coronary syndrome, myocardial infarction, stroke, and repeated cardiovascular procedures) and appear to be at higher risk for development of heart failure with preserved ejection fraction. Terminology such as coronary artery disease or coronary heart disease is often synonymous with obstructive atherosclerosis in the clinician's mind, leaving one at a loss to recognize or explain the phenomenon of MINOCA and INOCA with elevated risk. We review the available literature regarding stable and unstable ischemic heart disease that suggests that use of the ischemic heart disease (IHD) terminology matters for women, and should facilitate recognition of risk to provide potential treatment targets and optimized health.

Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate pathway

It is well known that there is an association of lower urinary tract symptoms/benign prostatic hypertrophy with cardiovascular disease, suggesting that lower urinary tract symptoms/benign prostatic hypertrophy is a risk factor for cardiovascular events. Vascular function, including endothelial function and vascular smooth muscle function, is involved in the pathogenesis, maintenance and development of atherosclerosis, leading to cardiovascular events. Vascular dysfunction per se should also contribute to lower urinary tract symptoms/benign prostatic hypertrophy. Both lower urinary tract symptoms/benign prostatic hypertrophy and vascular dysfunction have cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, aging, obesity and smoking. Inactivation of the phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate-nitric oxide pathway causes lower urinary tract symptoms/benign prostatic hypertrophy through an enhancement of sympathetic nervous activity, endothelial dysfunction, increase in Rho-associated kinase activity and vasoconstriction, and decrease in blood flow of pelvic viscera. Both endogenous nitric oxide and exogenous nitric oxide act as vasodilators on vascular smooth muscle cells through an increase in the content of cyclic guanosine 3',5'-monophosphate, which is inactivated by phosphodiesterase type 5. In a clinical setting, phosphodiesterase type 5 inhibitors are widely used in patients with lower urinary tract symptoms/benign prostatic hypertrophy. Phosphodiesterase type 5 inhibitors might have beneficial effects on vascular function through not only inhibition of cyclic guanosine 3',5'-monophosphate degradation, but also increases in testosterone levels and nitric oxide bioavailability, increase in the number and improvement of the function of endothelial progenitor cells, and decrease in insulin resistance. In the present review, the relationships between lower urinary tract symptoms/benign prostatic hypertrophy, the phosphodiesterase type 5-nitric oxide-cyclic guanosine 3',5'-monophosphate pathway, vascular function and cardiovascular outcomes are examined.

Endothelial dysfunction and abnormal vascular structure are simultaneously present in patients with heart failure with preserved ejection fraction

BACKGROUND

Endothelial dysfunction and abnormal vascular structure may be involved in the pathogenesis of chronic heart failure (HF). The purpose of this study was to evaluate simultaneously vascular function and vascular structure in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS

We measured flow-mediated vasodilatation (FMD) and nitroglycerine-induced vasodilation as indices of vascular function and intima-media thickness (IMT) as an index of vascular structure of the brachial artery in 41 patients with HFpEF (23 men and 18 women; mean age, 66±12yr) and 165 patients without HF (95 men and 70 women; mean age, 54±16yr).

RESULTS

FMD was significantly smaller in patients with HFpEF than in patients without HF (2.9±2.1% versus 4.6±2.7%, P=0.0002). Nitroglycerine-induced vasodilation was significantly smaller in patients with HFpEF than in patients without HF (9.3±4.1% versus 12.9±4.9%, P<0.0001). Brachial artery IMT was significantly larger in patients with HFpEF than in patients without HF (0.35±0.06mm versus 0.31±0.07mm, P=0.0002). After adjustment for age, sex, hypertension, dyslipidemia, and diabetes mellitus, the associations remained significant between HFpEF and FMD (odds ratio, 0.79; 95% confidence interval, 0.66-0.92; P=0.0032), nitroglycerine-induced vasodilation (odds ratio, 0.88; 95% confidence interval, 0.80-0.96; P=0.0039), and brachial artery IMT (odds ratio, 1.08; 95% confidence interval, 1.01-1.17; P=0.033).

CONCLUSIONS

These findings suggest that both endothelial dysfunction and abnormal vascular structure may contribute to the pathogenesis and maintenance of HFpEF. Endothelial function and vascular structure may be potential therapeutic targets for HFpEF.

Anti-thrombotic effects of nebivolol and carvedilol: Involvement of β2 receptors and COX-2/PGI2 pathways

BACKGROUND

Third generation β-adrenolytics, such as selective β1 adrenoceptor antagonist nebivolol and non-selective β1/β2 and α1 adrenoceptor antagonist carvedilol, display beneficial nitric oxide (NO)-dependent vasodilator activities that contribute to their therapeutic efficacy. In the present work, we analyzed whether nebivolol and carvedilol, as well as other β-adrenolytics with similar pharmacological profiles (selective β1 adrenoceptor antagonist - atenolol and non-selective α/β adrenoceptor antagonist - labetalol), possess the ability to induce PGI2-dependent anti-thrombotic activity in vivo in normotensive rats.

METHODS

Anti-thrombotic effects of nebivolol and carvedilol were studied in vivo in anaesthetized rats with extracorporeal circulation superfusing collagen strips. We also assessed vasodilation induced by these drugs in isolated perfused guinea pig hearts according to Langendorff's procedures.

RESULTS

Nebivolol (both d- and l-isomers) (0.1-1mgkg(-1)) and carvedilol (1-3mgkg(-1)), but not atenolol (1mgkg(-1)) or labetalol (3mgkg(-1)), induced a dose-dependent and sustained anti-thrombotic response in rat model of thrombosis with extracorporeal circulation. The cyclooxygenase (COX)-2 inhibitors, rofecoxib (1mgkg(-1)) and indomethacin (5mgkg(-1)) abrogated this response, while l-NAME (5mgkg(-1)) had no significant effect. In the presence of β1/β2 adrenoceptor antagonist nadolol (1mgkg(-1)), but not in the presence of selective β1 adrenoceptor antagonist atenolol (4mgkg(-1)), anti-thrombotic responses to nebivolol, as well as carvedilol, were lost. Neither nebivolol nor carvedilol affected platelet aggregation in vitro, however both nebivolol and carvedilol induced NO-dependent vasodilation in guinea pig coronary circulation that was not dependent on β2 adrenoceptors.

CONCLUSIONS

We demonstrated for the first time that nebivolol and carvedilol, independently of their adrenergic receptor blocking activities, induced anti-thrombotic effects in vivo that involved β2 adrenoceptors and the activation of the COX-2/PGI2 pathway.

Endothelial dysfunction in conduit arteries and in microcirculation. Novel therapeutic approaches

The vascular endothelium not only is a single monolayer of cells between the vessel lumen and the intimal wall, but also plays an important role by controlling vascular function and structure mainly via the production of nitric oxide (NO). The so called "cardiovascular risk factors" are associated with endothelial dysfunction, that reduces NO bioavailability, increases oxidative stress, and promotes inflammation contributing therefore to the development of atherosclerosis. The significant role of endothelial dysfunction in the development of atherosclerosis emphasizes the need for efficient therapeutic interventions. During the last years statins, angiotensin-converting enzyme inhibitors, angiotensin-receptor antagonists, antioxidants, beta-blockers and insulin sensitizers have been evaluated for their ability to restore endothelial function (Briasoulis et al., 2012). As there is not a straightforward relationship between therapeutic interventions and improvement of endothelial function but rather a complicated interrelationship between multiple cellular and sub-cellular targets, research has been focused on the understanding of the underlying mechanisms. Moreover, the development of novel diagnostic invasive and non-invasive methods has allowed the early detection of endothelial dysfunction expanding the role of therapeutic interventions and our knowledge. In the current review we present the available data concerning the contribution of endothelial dysfunction to atherogenesis and review the methods that assess endothelial function with a view to understand the multiple targets of therapeutic interventions. Finally we focus on the classic and novel therapeutic approaches aiming to improve endothelial dysfunction and the underlying mechanisms.

Carvedilol protects against iron-induced microparticle generation and apoptosis of endothelial cells

BACKGROUND

Increased circulating endothelial microparticles (EMPs) have been shown to associate with endothelial dysfunction. We explored the effect of iron on EMP generation by human umbilical vein endothelial cells (HUVECs) and the potential protective effect of carvedilol.

METHODS

FeCl 3 was added to HUVEC culture. Iron entry into cells was monitored using fluorescent microscopic imaging, while the quantity of EMPs that was released was determined by flow cytometry. The apoptosis of HUVECs was assessed by annexin V/propidium iodide assay and caspase-3 expression. Membrane bleb formation was visualized using electron microscopy. Intracellular production of reactive oxygen species (ROS) was also monitored. The effects of beta-blockers, carvedilol and propranolol on these processes were determined by co-incubation in a dose-dependent manner. Iron entry into HUVECs was not blocked by either beta-blocker. Iron induced the generation of EMPs, the formation of membrane blebs, the apoptosis of HUVECs and the production of ROS, each in a dose-dependent manner. Carvedilol, but not propranolol, ameliorated all of these processes.

RESULTS

Our result indicates that iron induces EMP generation and apoptosis of endothelial cells in association with increased oxidative stress.

CONCLUSION

The protective effects of carvedilol, via its antioxidant effect, may have therapeutic potential in patients with iron overload.

A critical review of the use of carvedilol in ischemic heart disease

β-Adrenergic receptor antagonists (β-blockers) have been recognized for their cardioprotective properties, prompting use of these pharmacologic agents to become more mainstream in acute myocardial infarction (AMI) and congestive heart failure (CHF). Despite their popularity as a class, the ability to protect the myocardium varies significantly between different agents. Carvedilol is a non-selective β-blocker with α₁-adrenergic receptor antagonism properties. It is unique among β-blockers because in addition to improving exercise tolerance and its anti-ischemic properties secondary to a reduction in heart rate and myocardial contractility, carvedilol exerts other beneficial effects including: antioxidant effects; reduction in neutrophil infiltration; apoptosis inhibition; reduction of vascular smooth muscle migration; and improvement of myocardial remodeling post-AMI. These properties, documented in animal models and subsequent clinical trials, are consistent with established evidence demonstrating decreased morbidity and mortality in patients with CHF and post-AMI. This article reviews the role of carvedilol compared with other β-blockers in the treatment of CHF and post-AMI management.

Effects of antihypertensive treatment on endothelial function

Essential hypertension is characterized by endothelial dysfunction due to reduced availability of nitric oxide (NO) secondary to increased generation of oxygen-free radicals. Some antihypertensive drugs may improve or restore endothelial function independently of their blood pressure lowering effect. The newer generation of β-blockers, such as nebivolol and carvedilol, which provide antioxidant activity, can improve endothelial function in patients with hypertension. Dihydropyridine and non-dihydropyridine calcium antagonists reverse impaired endothelium-dependent vasodilatation in different vascular districts, through a mechanism related to an antioxidant effect. However, conflicting results are found in the brachial artery. Angiotensin-converting enzyme (ACE) inhibitors improve endothelial function in subcutaneous, epicardial, brachial, and renal circulation, but they are ineffective in potentiating the impaired response to acetylcholine in the forearm of hypertensive patients. Angiotensin II receptor antagonists can restore endothelium-dependent vasodilatation to acetylcholine in subcutaneous microcirculation but not in that of the forearm muscle. They also improve basal NO release and decrease the vasoconstrictor effect of endogenous endothelin-1. Large-scale clinical trials are required to definitively demonstrate that treatment of endothelial dysfunction can improve the prognosis of patients with essential hypertension.

Endothelial function is unaffected by changing between carvedilol and metoprolol in patients with heart failure--a randomized study

Background

Carvedilol has been shown to be superior to metoprolol tartrate to improve clinical outcomes in patients with heart failure (HF), yet the mechanisms responsible for these differences remain unclear. We examined if there were differences in endothelial function, insulin stimulated endothelial function, 24 hour ambulatory blood pressure and heart rate during treatment with carvedilol, metoprolol tartrate and metoprolol succinate in patients with HF.

Methods

Twenty-seven patients with mild HF, all initially treated with carvedilol, were randomized to a two-month treatment with carvedilol, metoprolol tartrate or metoprolol succinate. Venous occlusion plethysmography, 24-hour blood pressure and heart rate measurements were done before and after a two-month treatment period.

Results

Endothelium-dependent vasodilatation was not affected by changing from carvedilol to either metoprolol tartrate or metoprolol succinate. The relative forearm blood flow at the highest dose of serotonin was 2.42 ± 0.33 in the carvedilol group at baseline and 2.14 ± 0.24 after two months continuation of carvedilol (P = 0.34); 2.57 ± 0.33 before metoprolol tartrate treatment and 2.42 ± 0.55 after treatment (p = 0.74) and in the metoprolol succinate group 1.82 ± 0.29 and 2.10 ± 0.37 before and after treatment, respectively (p = 0.27). Diurnal blood pressures as well as heart rate were also unchanged by changing from carvedilol to metoprolol tartrate or metoprolol succinate.

Conclusion

Endothelial function remained unchanged when switching the beta blocker treatment from carvedilol to either metoprolol tartrate or metoprolol succinate in this study, where blood pressure and heart rate also remained unchanged in patients with mild HF.

Trial registration

Current Controlled Trials NCT00497003

Therapeutic effect of {beta}-adrenoceptor blockers using a mouse model of dilated cardiomyopathy with a troponin mutation

AIMS

Extensive clinical studies have demonstrated that beta-adrenoceptor blocking agents (beta-blockers) are beneficial in the treatment of chronic heart failure, which is due to various aetiologies, including idiopathic dilated cardiomyopathy (DCM) and ischaemic heart disease. However, little is known about the therapeutic efficacy of beta-blockers in the treatment of the inherited form of DCM, of which causative mutations have recently been identified in various genes, including those encoding cardiac sarcomeric proteins. Using a mouse model of inherited DCM with a troponin mutation, we aim to study the treatment benefits of beta-blockers.

METHODS AND RESULTS

Three different types of beta-blockers, carvedilol, metoprolol, and atenolol, were orally administered to a knock-in mouse model of inherited DCM with a deletion mutation DeltaK210 in the cardiac troponin T gene (TNNT2). Therapeutic effects were examined on the basis of survival and myocardial remodelling. The lipophilic beta(1)-selective beta-blocker metoprolol was found to prevent cardiac dysfunction and remodelling and extend the survival of knock-in mice. Conversely, both the non-selective beta-blocker carvedilol and the hydrophilic beta(1)-selective beta-blocker atenolol had no beneficial effects on survival and myocardial remodelling in this mouse model of inherited DCM.

CONCLUSION

The highly lipophilic beta(1)-selective beta-blocker metoprolol, known to prevent ventricular fibrillation via central nervous system-mediated vagal activation, may be especially beneficial to DCM patients showing a family history of frequent sudden cardiac death, such as those with a deletion mutation DeltaK210 in the TNNT2 gene.

Differential effects of arginine methylation on diastolic dysfunction and disease progression in patients with chronic systolic heart failure

AIMS

To investigate the association of arginine methylation with myocardial function and prognosis in chronic systolic heart failure patients.

METHODS AND RESULTS

Asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), as well as N-mono-methylarginine (MMA) and methyl-lysine, were simultaneously measured by tandem mass spectrometry in 132 patients with chronic systolic heart failure with echocardiographic evaluation and follow-up. Increasing ADMA and SDMA levels were associated with elevated natriuretic peptide levels (both P < 0.001), and increasing SDMA levels were associated with worsening renal function (P < 0.001). Higher plasma levels of methylated arginine metabolites (but not methyl-lysine) were associated with the presence of left ventricular (LV) diastolic dysfunction (E/septal E', Spearman's r = 0.31-0.36, P < 0.001). Patients taking beta-blockers had lower ADMA levels than those not taking beta-blockers [0.42 (0.33, 0.50) vs. 0.51 (0.40, 0.58), P < 0.001]. Only increasing ADMA levels were associated with advanced right ventricular (RV) systolic dysfunction. Elevated ADMA levels remained a consistent independent predictor of adverse clinical events (hazard ratio = 1.64, 95% CI: 1.20-2.22, P = 0.002).

CONCLUSION

In chronic systolic heart failure, accumulation of methylated arginine metabolites is associated with the presence of LV diastolic dysfunction. Among the methylated derivatives of arginine, ADMA provides the strongest independent prediction of disease progression and adverse long-term outcomes.