Effects of nebivolol therapy on endothelial functions in cardiac syndrome X

[Chest pain and cardiovascular diseases in women : Diagnostics and treatment]

Cardiovascular diseases (CVD) are the leading cause of global mortality not only in men but also in women. The incidence of CVD significantly increases in women, especially after the menopause. Sex and gender differences in the incidence, prevalence and mortality of CVD are due to hormonal, anatomical, and sociocultural differences. As part of the primary and secondary prevention of coronary heart disease (CHD), risk factors specific for women, such as autoimmune diseases and pregnancy-associated diseases (e.g., gestational diabetes and pre-eclampsia) should also be taken into account in addition to the classical cardiovascular risk factors. Furthermore, in women with angina pectoris it should be considered that women in particular frequently suffer from ischemia with nonobstructive coronary arteries (INOCA) that can be caused, for example, by coronary microvascular dysfunction (CMD) or coronary spasms. Based on this, the diagnostics should not be terminated in symptomatic women after coronary angiography with normal epicardial vessels. A targeted diagnostics for CMD and coronary spasms should be carried out at an early stage.

Ischemia and no obstructive coronary arteries (INOCA): A narrative review

Myocardial ischemia with no obstructive coronary arteries (INOCA) is a chronic coronary syndrome condition that is increasingly being recognized as a substantial contributor to adverse cardiovascular mortality and outcomes, including myocardial infarction and heart failure with preserved ejection fraction (HFpEF). While INOCA occurs in both women and men, women are more likely to have the finding of INOCA and are more adversely impacted by angina, with recurrent hospitalizations and a lower quality of life with this condition. Abnormal epicardial coronary vascular function and coronary microvascular dysfunction (CMD) have been identified in a majority of INOCA patients on invasive coronary function testing. CMD can co-exist with obstructive epicardial coronary artery disease (CAD), diffuse non-obstructive epicardial CAD, and with coronary vasospasm. Epicardial vasospasm can also occur with normal coronary arteries that have no atherosclerotic plaque on intravascular imaging. While all predisposing factors are not clearly understood, cardiometabolic risk factors, and endothelium dependent and independent mechanisms that increase oxidative stress and inflammation are associated with microvascular injury, CMD and INOCA. Cardiac autonomic dysfunction has also been implicated in abnormal vasoreactivity and persistent symptoms. INOCA is under-recognized and under-diagnosed, partly due to the heterogenous patient populations and mechanisms. However, diagnostic testing methods are available to guide INOCA management. Treatment of INOCA is evolving, and focuses on cardiac risk factor control, improving ischemia, reducing atherosclerosis progression, and improving angina and quality of life. This review focuses on INOCA, relations to HFpEF, available diagnostics, current and investigational therapeutic strategies, and knowledge gaps in this condition.

Comparison of nebivolol versus diltiazem in improving coronary artery spasm and quality of life in patients with hypertension and vasospastic angina: A prospective, randomized, double-blind pilot study

Background

Beta-blockers are often not the preferred treatment for patients with vasospastic angina. However, nebivolol, beta-blocker with nitric oxide-releasing effect, could theoretically improve coronary vasospasm. We compared nebivolol versus diltiazem in improving coronary vasospasm and quality of life in patients with hypertensive vasospastic angina during a 12-week follow-up.

Methods

Fifty-one hypertensive patients with documented coronary vasospasm were randomly allocated into 3 treatment groups: (1) Nebivolol Group (5mg for 2 weeks/10mg for 10 weeks); (2) Diltiazem Group (90mg for 2 weeks/180mg for 10 weeks); (3) Low-dose Combination Group (2.5mg + 45mg for 2 weeks/5mg + 90mg for 10 weeks). The primary endpoint was to compare the percent changes in coronary vasospasm at 12 weeks from baseline among the 3 groups. The secondary endpoints included changes in quality of life based on the Seattle Angina Questionnaire and changes in blood pressure at 12 weeks from baseline.

Results

Significant improvements in coronary vasospasm were found in all groups; however, the improvement in percent changes in coronary artery spasm was greatest in the Diltiazem Group (50.4±8.8% vs. 67.8±12.8% vs. 46.8±12.3%, Nebivolol Group vs. Diltiazem Group p = 0.008; Nebivolol Group vs. Low-dose Combination Group p = 0.999; Diltiazem Group vs. Low-dose Combination Group p = 0.017). The overall Seattle Angina Questionnaire scores were significantly elevated at 12 weeks compared to the baseline in entire study population. There were no significant differences between the three groups in the overall Seattle Angina Questionnaire score changes and blood pressure changes.

Conclusions

Both nebivolol and diltiazem showed significant coronary vasospasm reduction effect, but the effect was greater for diltiazem.

Effect of Chinese medicine for promoting blood circulation on microvascular angina: A systematic review and meta-analysis

BACKGROUND

Blood-activating drugs (BADs) are widely used to treat microvascular angina in China. This study aims to summarize relevant evidence from randomized controlled trials (RCTs) to assess the efficacy and safety of BADs in the treatment of microvascular angina.

METHODS

We searched for relevant studies before June 2019 from seven databases. Twenty-four studies were included of 1903 patients with microvascular angina. All studies compared the use of traditional Chinese medicine for activating blood circulation (BADs) and Western medicine (WM) with the use of Western medicine alone.

RESULTS

In all, 15 trials reported a significant effect of BADs on improving clinical symptoms compared with the control treatment (P < .00001), and 8 trials reported significant effects of BADs on reducing the frequency of angina pectoris attacks compared with Western medicine treatment (P < .00001). The pooled results also demonstrated that BADs provided a significant benefit in reducing the dosage of nitroglycerin required (P = .02), the maximum range of ST-segment depression (P = .003) and the descending degree of the ST-T segment of ECG (P = .0002); prolonging the total time of treadmill exercise (P < .00001) and the time of ST-segment depression of 1 mm (P = .002); enhancing the total effective rate of Traditional Chinese Medicine (TCM) syndromes (P < .00001); improving endothelial function (P < .00001); and reducing the levels of high-sensitivity C-reactive protein (hs-CRP) (P < .00001). BAD treatment showed no statistically significant effect on the levels of TNF-a (P = .8) or IL-6 (P = .13). No severe adverse events were reported.

CONCLUSION

This meta-analysis shows that BADs are effective for the treatment of microvascular angina. Although concerns regarding selective bias and low methodological quality were raised, our findings suggest that BADs are beneficial for patients with microvascular angina and should be given priority for future clinical studies.

Cardiac implications of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on platelet-mediated micro-thrombi formation, leading to microvascular thrombosis. Autopsy studies showed that cardiac arrest and myocardial infarction are the most common immediate causes of death in these patients. Clinical manifestations of cardiac involvement in TTP vary dramatically, from asymptomatic elevation of cardiac biomarkers, to heart failure, MI and sudden cardiac death. There is limited knowledge about optimal cardiac evaluation and management in patients with TTP. The absence of typical cardiac symptoms, combined with complicated multi-organ involvement in TTP, may contribute to the under-utilization of cardiac evaluation and treatment. Prompt diagnosis and timely initiation of effective therapy could be critically important in selected cases. Based on our experience and this review of the literature, we developed several recommendations for focused cardiac evaluation for patients with acute TTP: (1) patients with suspected or confirmed TTP should be screened for the potential presence of cardiac involvement with detailed history and physical, electrocardiogram and cardiac enzymes; (2) clinical deterioration of TTP patients warrants immediate cardiac reevaluation; (3) TTP patients with clinical evidence of cardiac involvement should be monitored for telemetry, cardiac biomarkers and evaluated with transthoracic echocardiography. These patients require urgent targeted TTP treatment as well as cardiac-specific treatment. Aspirin therapy is indicated for all TTP patients. Since epicardial coronary artery involvement is rare, cardiac catheterization is usually not required, given the high risk for hemorrhage and kidney injury; (4) we recommend evidence-based medical therapy for ischemic symptoms and heart failure. TTP patients with evidence of cardiac involvement would also benefit from routine cardiology follow up during remission.

Optimizing the host substrate environment for cardiac angiogenesis, arteriogenesis, and myogenesis

INTRODUCTION

The diseased host milieu, such as endothelial dysfunction (ED), decreased NO bioavailability, and ischemic/inflammatory post-MI environment, hamper the clinical success of existing cardiac regenerative therapies. Area covered: In this article, current strategies including pharmacological and nonpharmacological approaches for improving the diseased host milieu are reviewed. Specifically, the authors provide focus on: i) the mechanism of ED in patients with cardiovascular diseases, ii) the current results of ED improving strategies in pre-clinical and clinical studies, and iii) the use of biomaterials as a novel modulator in damaged post-MI environment. Expert opinion: Adjunct therapies which improve host endothelial function have demonstrated promising outcomes, potentially overcoming disappointing results of cell therapy in human studies. In the future, elucidation of the interactions between the host tissue and therapeutic agents, as well as downstream signaling pathways, will be the next challenges in enhancing regenerative therapy. More careful investigations are also required to establish these agents' safety and efficacy for wide usage in humans.

Coronary microvascular dysfunction: sex-specific risk, diagnosis, and therapy

Cardiovascular disease is the leading cause of death worldwide. In the presence of signs and symptoms of myocardial ischaemia, women are more likely than men to have no obstructive coronary artery disease (CAD). Women have a greater burden of symptoms than men, and are often falsely reassured despite the presence of ischaemic heart disease because of a lack of obstructive CAD. Coronary microvascular dysfunction should be considered as an aetiology for ischaemic heart disease with signs and symptoms of myocardial ischaemia, but no obstructive CAD. Coronary microvascular dysfunction is defined as impaired coronary flow reserve owing to functional and/or structural abnormalities of the microcirculation, and is associated with an adverse cardiovascular prognosis. Therapeutic lifestyle changes as well as antiatherosclerotic and antianginal medications might be beneficial, but clinical outcome trials are needed to guide treatment. In this Review, we discuss the prevalence, presentation, diagnosis, and treatment of coronary microvascular dysfunction, with a particular emphasis on ischaemic heart disease in women.

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.

Microvascular angina: an update on diagnosis and treatment

ABSTRACT 

Many patients with chest pain who are relieved to learn that they have no obstructive stenoses at diagnostic angiography are misclassified as having noncardiac chest pain. Only recently have we developed the conceptual framework and diagnostic tools to understand that ischemic heart disease is not exclusively caused by obstructive coronary artery disease, but often has its origin in the microcirculation. This article will focus on the diagnosis and treatment of microvascular angina as a cause of myocardial ischemia in patients with abnormal but ‘normal appearing’ coronary arteries.

Current Diagnostic and Therapeutic Strategies in Microvascular Angina

Microvascular angina is common among patients with signs and symptoms of acute coronary syndrome and is associated with an increased risk of cardiovascular and cerebrovascular events. Unfortunately, microvascular is often under-recognized in clinical settings. The diagnosis of microvascular angina relies on assessment of the functional status of the coronary microvasculature. Invasive strategies include acetylcholine provocation, intracoronary Doppler ultrasound, and intracoronary thermodilution; noninvasive strategies include cardiac positron emission tomography (PET), cardiac magnetic resonance, and Doppler echocardiography. Once the diagnosis of microvascular angina is established, treatment is focused on improving symptoms and reducing future risk of cardiovascular and cerebrovascular events. Pharmacologic options and lifestyle modifications for patients with microvascular angina are similar to those for patients with coronary artery disease.

Endothelial dysfunction in metabolic and vascular disorders

Vascular endothelium has important regulatory functions in the cardiovascular system and a pivotal role in the maintenance of vascular health and metabolic homeostasis. It has long been recognized that endothelial dysfunction participates in the pathogenesis of atherosclerosis from early, preclinical lesions to advanced, thrombotic complications. In addition, endothelial dysfunction has been recently implicated in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Considering that states of insulin resistance (eg, metabolic syndrome, impaired fasting glucose, impaired glucose tolerance, and T2DM) represent the most prevalent metabolic disorders and risk factors for atherosclerosis, it is of considerable scientific and clinical interest that both metabolic and vascular disorders have endothelial dysfunction as a common background. Importantly, endothelial dysfunction has been associated with adverse outcomes in patients with established cardiovascular disease, and a growing body of evidence indicates that endothelial dysfunction also imparts adverse prognosis in states of insulin resistance. In this review, we discuss the association of insulin resistance and T2DM with endothelial dysfunction and vascular disease, with a focus on the underlying mechanisms and prognostic implications of the endothelial dysfunction in metabolic and vascular disorders. We also address current therapeutic strategies for the improvement of endothelial dysfunction.

Nebivolol: vasodilator properties and evidence for relevance in treatment of cardiovascular disease

β-adrenergic blocking agents, a pharmacologically diverse class of cardiovascular medications, are recommended as first-line treatment for patients with hypertension and concomitant structural heart disease, and for angina and heart failure. Many within-class differences exist, from pharmacokinetics and pharmacodynamics to ancillary effects, such as intrinsic sympathomimetic activity, antiarrhythmic activity, α-1 adrenergic receptor blockade affinity, and direct vasodilation. Nebivolol is a third-generation, β1 selective, long acting β-blocker, which causes direct vasodilation via endothelium-dependent nitric oxide stimulation. The vasodilatory actions of nebivolol might result in clinical effects with some distinct properties. Differences from other β-blockers might include improvement of endothelial function, enhancement of forward flow in muscular resistance arteries, maintenance of exercise tolerance, and overall improved tolerability, side effect profile, and adherence. Nebivolol has been shown to be a clinically effective β-blocker for treatment as initial or add-on therapy for systemic hypertension, as an antianginal agent, and as therapy for patients with heart failure. These properties position nebivolol as a treatment option for patients with hypertension and/or structural heart disease, although its precise role in the therapeutic armamentarium remains to be clarified.

Therapeutic approach in the improvement of endothelial dysfunction: the current state of the art

The endothelium has a central role in the regulation of blood flow through continuous modulation of vascular tone. This is primarily accomplished by balanced release of endothelial relaxing and contractile factors. The healthy endothelial cells are essential for maintenance of vascular homeostasis involving antioxidant, anti-inflammatory, pro-fibrinolytic, anti-adhesive, or anticoagulant effects. Oppositely, endothelial dysfunction is primarily characterized by impaired regulation of vascular tone as a result of reduced endothelial nitric oxide (NO) synthase activity, lack of cofactors for NO synthesis, attenuated NO release, or increased NO degradation. So far, the pharmacological approach in improving/reversal of endothelial dysfunction was shown to be beneficial in clinical trials that have investigated actions of different cardiovascular drugs. The aim of this paper was to summarize some of the latest clinical findings related to therapeutic possibilities for improving endothelial dysfunction in different pathological conditions. In the majority of presented clinical investigations, the assessment of improvement or reversal of endothelial dysfunction was performed through the flow-mediated dilatation measurement, and in some of those endothelial progenitor cells' count was used for the same purpose. Still, given the fast and continuous development of this field, the evidence acquisition included the MEDLINE data base screening and the selection of articles published between 2010 and 2012.

ABO-Rh blood groups distribution in cardiac syndrome X patients

Background:

Data on frequency distribution of ABO-Rh blood groups in cardiac syndrome X (CSX) patients are not available. We aimed to investigate the distribution of ABO-Rh blood groups in these patients.

Materials and Methods:

A total of 247 CSX patients’ records were reviewed in a cross-sectional study from 2006 to 2010. One hundred forty six patients (59.1%) were female, and the mean patient age was 52 ± 11 years. The frequency of ABO-Rh blood groups was compared to the frequency of these blood groups in the West-Azerbaijan province, Iran; general population.

Results:

Blood groups distribution among CSX patients showed phenotypes A, B, AB, O and Rh negative as 33.1%, 21.9%, 9.3%, 35.8%, and 7.9%, respectively. According to our results, there were no differences in ABO-Rh blood groups distribution between CSX patients and normal population.

Conclusion:

These data suggest that ABO-Rh blood groups might be unassociated with CSX.