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Atrial fibrillation (AF) is prevalent in diabetes mellitus (DM); however, the basis for this is unknown. This study investigated AF susceptibility and atrial electrophysiology in type 1 diabetic Akita mice using in vivo intracardiac electrophysiology, high-resolution optical mapping in atrial preparations, and patch clamping in isolated atrial myocytes. qPCR and western blotting were used to assess ion channel expression. Akita mice were highly susceptible to AF in association with increased P-wave duration and slowed atrial conduction velocity. In a second model of type 1 DM, mice treated with streptozotocin (STZ) showed a similar increase in susceptibility to AF. Chronic insulin treatment reduced susceptibility and duration of AF and shortened P-wave duration in Akita mice. Atrial action potential (AP) morphology was altered in Akita mice due to a reduction in upstroke velocity and increases in AP duration. In Akita mice, atrial Na(+) current (I(Na)) and repolarizing K(+) current (I(K)) carried by voltage gated K(+) (K(v)1.5) channels were reduced. The reduction in I(Na) occurred in association with reduced expression of SCN5a and voltage gated Na(+) (Na(V)1.5) channels as well as a shift in I(Na) activation kinetics. Insulin potently and selectively increased I(Na) in Akita mice without affecting I(K). Chronic insulin treatment increased I(Na) in association with increased expression of Na(V)1.5. Acute insulin also increased I(Na), although to a smaller extent, due to enhanced insulin signaling via phosphatidylinositol 3,4,5-triphosphate (PIP(3)). Our study reveals a critical, selective role for insulin in regulating atrial I(Na), which impacts susceptibility to AF in type 1 DM.

This is Part 2 of a two-part review summarising current knowledge on biomarkers of atherosclerosis. Part 1 addressed serological biomarkers. Here, in part 2 we address genetic and imaging markers, and other developments in predicting risk. Further improvements in risk stratification are expected with the addition of genetic risk scores. In addition to single nucleotide polymorphisms (SNPs), recent advances in epigenetics offer DNA methylation profiles, histone chemical modifications, and micro-RNAs as other promising indicators of atherosclerosis. Imaging biomarkers are better studied and already have a higher degree of clinical applicability in cardiovascular (CV) event prediction and detection of preclinical atherosclerosis. With new methodologies, such as proteomics and metabolomics, discoveries of new clinically applicable biomarkers are expected.

The mechanistic target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that senses and integrates environmental information into cellular regulation and homeostasis. Accumulating evidence has suggested a master role of mTOR signalling in many fundamental aspects of cell biology and organismal development. mTOR deregulation is implicated in a broad range of pathological conditions, including diabetes, cancer, neurodegenerative diseases, myopathies, inflammatory, infectious, and autoimmune conditions. Here, we review recent advances in our knowledge of mTOR signalling in mammalian physiology. We also discuss the impact of mTOR alteration in human diseases and how targeting mTOR function can treat human diseases.

Heart failure (HF) with preserved ejection fraction (HFpEF) is a major public health problem with cases projected to double over the next two decades. There are currently no US Food and Drug Administration–approved therapies for the health-related outcomes of HFpEF. However, considering the high prevalence of this heterogeneous syndrome, a directed therapy for HFpEF is one the greatest unmet needs in cardiovascular medicine. Additionally, there is currently a lack of mechanistic understanding about the pathobiology of HFpEF. The phenotyping of HFpEF patients into pathobiological homogenous groups may not only be the first step in understanding the molecular mechanism but may also enable the development of novel targeted therapies. As obesity is one of the most common comorbidities found in HFpEF patients and is associated with many cardiovascular effects, it is a viable candidate for phenotyping. Large outcome trials and registries reveal that being obese is one of the strongest independent risk factors for developing HFpEF and that this excess risk may not be explained by traditional cardiovascular risk factors. Recently, there has been increased interest in the intertissue communication between adipose tissue and the heart. Evidence suggests that the natriuretic peptide clearance receptor (NPR-C) pathway may play a role in the development and pathobiology of obesity-related HFpEF. Therefore, therapeutic manipulations of the NPR-C pathway may represent a new pharmacological strategy in the context of underlying molecular mechanisms.

Background and objectives Reports comparing the characteristics of patients and their clinical outcomes between community-acquired (CA) and hospital-acquired (HA) COVID-19 have not yet been reported in the literature. We aimed to characterise and compare clinical, biochemical and haematological features, in addition to clinical outcomes, between these patients. Methods This multi-centre, retrospective, observational study enrolled 488 SARS-CoV-2 positive patients - 339 with CA infection and 149 with HA infection. All patients were admitted to a hospital within the University Hospitals of Morecambe Bay NHS Foundation Trust between March 7th and May 18th, 2020. Results The CA cohort comprised of a significantly younger population, median age 75 years, versus 80 years in the HA cohort (P = 0·0002). Significantly less patients in the HA group experienced fever (P = 0·03) and breathlessness (P

Visual Abstract, Highlights • SAN disease is prevalent in hypertension and heart failure and can be induced by chronic Ang II treatment in mice. • Ang II caused SAN disease in mice in association with impaired electrical conduction, reduction in the hyperpolarization-activated current (If) in SAN myocytes, and increased SAN fibrosis. • Ang II-induced SAN disease was worsened in mice lacking NPR-C in association with enhanced SAN fibrosis. • Mice co-treated with Ang II and an NPR-C agonist (cANF) were protected from SAN disease. • NPR-C may represent a new target to protect against Ang II-induced SAN disease., Summary Sinoatrial node (SAN) disease mechanisms are poorly understood, and therapeutic options are limited. Natriuretic peptide(s) (NP) are cardioprotective hormones whose effects can be mediated partly by the NP receptor C (NPR-C). We investigated the role of NPR-C in angiotensin II (Ang II)-mediated SAN disease in mice. Ang II caused SAN disease due to impaired electrical activity in SAN myocytes and increased SAN fibrosis. Strikingly, Ang II treatment in NPR-C−/− mice worsened SAN disease, whereas co-treatment of wild-type mice with Ang II and a selective NPR-C agonist (cANF) prevented SAN dysfunction. NPR-C may represent a new target to protect against the development of Ang II-induced SAN disease.

Atrial fibrillation (AF) is prevalent in hypertension and elevated angiotensin II (Ang II); however, the mechanisms by which Ang II leads to AF are poorly understood. Here, we investigated the basis for this in mice treated with Ang II or saline for 3 weeks. Ang II treatment increased susceptibility to AF compared to saline controls in association with increases in P wave duration and atrial effective refractory period, as well as reductions in right and left atrial conduction velocity. Patch-clamp studies demonstrate that action potential (AP) duration was prolonged in right atrial myocytes from Ang II treated mice in association with a reduction in repolarizing K+ currents. In contrast, APs in left atrial myocytes from Ang II treated mice showed reductions in upstroke velocity and overshoot, as well as greater prolongations in AP duration. Ang II reduced Na+ current (INa) in the left, but not the right atrium. This reduction in INa was reversible following inhibition of protein kinase C (PKC) and PKCα expression was increased selectively in the left atrium in Ang II treated mice. The transient outward K+ current (Ito) showed larger reductions in the left atrium in association with a shift in the voltage dependence of activation. Finally, Ang II caused fibrosis throughout the atria in association with changes in collagen expression and regulators of the extracellular matrix. This study demonstrates that hypertension and elevated Ang II cause distinct patterns of electrical and structural remodeling in the right and left atria that collectively create a substrate for AF.

The sphingolipids ceramide (Cer), ceramide-1-phosphate (C1P), sphingosine (Sph), and sphingosine-1-phosphate (S1P)) are key signaling molecules that regulate many patho-biological processes. During the last decade, they have gained increasing attention since they may participate in important and numerous retinal processes, such as neuronal survival and death, proliferation and migration of neuronal and vascular cells, inflammation, and neovascularization. Cer for instance has emerged as a key mediator of inflammation and death of neuronal and retinal pigment epithelium cells in experimental models of retinopathies such as glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa. S1P may have opposite biological actions, preventing photoreceptor and ganglion cell degeneration but also promoting inflammation, fibrosis, and neovascularization in AMD, glaucoma, and pro-fibrotic disorders. Alterations in Cer, S1P, and ceramide 1- phosphate may also contribute to uveitis. Furthermore, use of inhibitors that either prevent Cer increase or modulate S1P signaling, such as Myriocin, desipramine, and Fingolimod (FTY720), have been shown to preserve neuronal viability and retinal function. Collectively, the expanding role for these sphingolipids in the modulation of vital processes in retina cell types and in their dysregulation in retinal degenerations makes them attractive therapeutic targets.

Several epidemiological studies reported an inverse relationship between plasma high-density lipoprotein (HDL) cholesterol levels and atherosclerotic cardiovascular disease (ASCVD). However, therapeutic interventions targeted at raising HDL-cholesterol failed to improve cardiovascular outcomes, suggesting that HDL components distinct from cholesterol may account for the anti-atherothrombotic effects attributed to this lipoprotein. Sphingosine-1-phosphate (S1P) and the acute phase protein serum amyloid A (SAA) have been identified as integral constituents of HDL particles. Evidence suggests that S1P and SAA levels within HDL particles may be affected by inflammation and oxidative stress, which are coexisting processes underlying ASCVD. Because SAA, an inflammation-related marker, and S1P, an anti-atherothrombotic marker, have relatively clear opposite characteristics among the HDL-associated proteins, the approach of assessing the two markers simultaneously may provide new insights in clinical practice (S1P/SAA Index). This review focuses on evidence in support of the concept that the S1P/SAA Index may affect the HDL atheroprotective properties and may, therefore represent a potential target for therapeutic interventions.

Obesity is a complex condition classically characterised by excessive body fat accumulation and represents one of the most important public health problems worldwide. Although several epidemiological studies have shown that elevated BMI is associated with higher morbidity, and with increased rate of death from all causes and from cardiovascular disease, accumulating evidence suggests that being overweight or obese may be protective (the so-called obesity paradox), at least in chronic diseases. These observations, not only question the validity of the BMI system, but also raise the intriguing question of whether we should redefine what the normal range of BMI is in individuals suffering from a chronic disease. In the present article, we review the available information on the association between elevated BMI and increased morbidity and mortality including obesity-related paradoxes, explore key aspects of the role and limitations of BMI as a measure of increased adiposity and outline potential solutions to address the current controversies regarding the impact of obesity on human health.

In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) is common and represents a strong predictor of death. Despite recent advances in the pathophysiological understanding there is as yet no prospect of cure of this deadly clinical entity and the majority of patients continue to progress to right ventricular failure and die. Furthermore, there is no single medical treatment currently approved for PH related to HF. There is, therefore an urgent unmet need to identify novel pharmacological agents that will prevent the progressive increased or reverse the elevated pulmonary arterial pressures while enhancing cardiac performance in HF.We here reported, for the first time, using a pressure-loop (P-V) conductance catheter system, that a specific natriuretic peptides clearance receptors' agonist, the ring-deleted atrial natriuretic peptide analogue, cANF4-23 (cANF) reduces pulmonary artery pressures. Strikingly, the administration of the cANF in these mice decreased the RVSP by 50% (n=5, F 25.687, DF 14, p0.001) and heart rate (HR) by 11% (n=5, F 25.69, DF 14, p0.001) as well as enhancing cardiac performance including left ventricular contractility in mice. Most strikingly, mice lacking NPR-C were much more susceptible to develop HF, indicating that NPR-C is a critical protective receptor in the heart.Natriuretic peptides clearance receptors' agonists may, therefore represent a novel and attractive therapeutic strategy for PH related to HF, and ultimately improves the life expectancy and quality for millions of people around the planet.

The renin angiotensin system (RAS) regulates fluid balance, blood pressure and maintains vascular tone. The potent vasoconstrictor angiotensin II (Ang II) produced by angiotensin-converting enzyme (ACE) comprises the classical RAS. The non-classical RAS involves the conversion of Ang II via ACE2 into the vasodilator Ang (1-7) to counterbalance the effects of Ang II. Furthermore, ACE2 converts AngA into another vasodilator named alamandine. The over activation of the classical RAS (increased vasoconstriction) and depletion of the non-classical RAS (decreased vasodilation) results in vascular dysfunction. Vascular dysfunction is the leading cause of atherosclerosis and cardiovascular disease (CVD). Additionally, local RAS is expressed in various tissues and regulates cellular functions. RAS dysregulation is involved in other several diseases such as inflammation, renal dysfunction and even cancer growth. An approach in restoring vascular dysfunction and other pathological diseases is to either increase the activity of ACE2 or reduce the effect of the classical RAS by counterbalancing Ang II effects. The antitrypanosomal agent, diminazene aceturate (DIZE), is one approach in activating ACE2. DIZE has been shown to exert beneficial effects in CVD experimental models of hypertension, myocardial infarction, type 1 diabetes and atherosclerosis. Thus, this review focuses on DIZE and its effect in several tissues such as blood vessels, cardiac, renal, immune and cancer cells.

B-type natriuretic peptide (BNP) exhibits roles in natriuresis and diuresis, making it an ideal drug that may aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these have demonstrated beneficial outcomes. The current challenge for BNP research in acute HF lies in addressing a failure of concept and a reluctance to abandon an ineffective research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP, as well as better integration of basic and clinical science.

Idiopathic Pulmonary Arterial Hypertension (IPAH) is a deadly and disabling disease characterized by severe vascular remodeling of small pulmonary vessels by fibroblasts, myofibroblasts and vascular smooth muscle cell proliferation. Recent studies suggest that the Natriuretic Peptide Clearance Receptor (NPR-C) signaling pathways may play a crucial role in the development of IPAH. Reduced expression or function of NPR-C signaling in pulmonary artery smooth muscle cells may contribute to the pulmonary vascular remodeling, which is characteristic of this disease. The likely mechanisms may involve an impaired interaction between NPR-C, specific growth factors and other signal transduction pathways including but not limited to Gqα/mitogen-activated protein kinase (MAPK)/PI3K and AKT signaling. The resulting failure of growth suppression in pulmonary artery smooth muscle cells provides critical clues to the cellular pathobiology of IPAH. The reciprocal regulation of NPR-C signaling in models of tissue remodeling may thus provide new insights to our understanding of IPAH.

Gastric cancer is a multifactorial disease associated with a combination of and environmental factors. Each year, one million new gastric cancer cases are diagnosed worldwide and two-thirds end up losing the battle with this devastating disease. Currently, surgery represents the only effective treatment option for patients with early stage tumors. However, the asymptomatic phenotype of this disease during the early stages poses as a significant limiting factor to diagnosis and often renders treatments ineffective. To address these issues, scientists are focusing on personalized medicine and discovering new ways to treat cancer patients. Emerging therapeutic options include the transient receptor potential (TRP) channels. Since their discovery, TRP channels have been shown to contribute significantly to the pathophysiology of various cancers, including gastric cancer. This review will summarize the current knowledge about gastric cancer and provide a synopsis of recent advancements on the role and involvement of TRP channels in gastric cancer as well as a discussion of the benefits of targeting TPR channel in the clinical management of gastric cancer.

Background:Biomechanical stress and inflammatory biomarkers relate to global contractility dysfunction; however, adding these biomarkers into a risk model constructed on clinical data does not improve its prediction value in chronic heart failure (CHF).Aim:The aim of this study was to evaluate whether biomarkers predict declining of left ventricular global contractility function in diabetic patients with ischemia-induced CHF.Patients and Methods:The study retrospectively evolved 54 diabetic patients who had systolic or diastolic ischemia-induced CHF that was defined as left-ventricular ejection fraction (LVEF) ≤45% or 46-55% respectively assessed by quantitative echocardiography and other conventional criteria according to current clinical guidelines. Two-dimensional transthoracic echocardiography and tissue Doppler imaging were performed according to a conventional method. Radial, longitudinal, and circumferential strain and strain rate values were obtained by speckle-tracking Imaging analysis of both LV short axis and long axis views. Serum adiponectin, NT-pro brain natriuretic peptide (BNP), osteoprotegerin, and hs- C-reactive protein (CRP) were determined at baseline by ELISA.Results:We found lower global longitudinal strain and strain rate in diabetic patients with LVEF Conclusion:We suggest that osteoprotegerin may be useful in improving the NT-proBNP based model as predictor of decreased global contractility function in diabetic patients with CHF.

Background Assessment of coronary flow is only performed during pharmacological tests. Supine bicycle tests permit the visualization of coronary flow assessments during exercise. Purpose To assess the parameters of coronary flow in the left anterior descending artery (LAD) during exercise, which could be a sign of significant LAD narrowing. Material and Methods A total of 253 patients were enrolled: Group 1, 186 non-selective participants before undergoing a coronary angiography; and Group 2, 67 controls without coronary artery disease (CAD). All the patients performed a supine bicycle echocardiography test. Coronary flow velocities and coronary flow velocity reserve (CFVR) were measured at the mid-segment of the LAD during exercise. Patients in Group 1 underwent a coronary angiography. Results In comparison with participants without significant LAD stenosis, patients with LAD lesions had a lower ΔV (16 ± 21 vs. 27 ± 20 cm/s, P Conclusion Non-invasive CFVR measurement in the LAD could provide valuable additional information to a conventional echocardiography exercise test. In routine clinical practice, CFVR is sufficient for a diagnosis of severe stenosis.

Background: Atrial fibrillation (AF) commonly occurs in hypertension and in association with elevated Ang II (angiotensin II) levels. The specific mechanisms underlying Ang II–mediated AF are unclear, and interventions to prevent the effects of Ang II are lacking. NPs (natriuretic peptides), which elicit their effects through specific NP receptors, including NPR-C (natriuretic peptide receptor-C), are cardioprotective hormones that affect cardiac structure and function. Methods: This study used wild-type and NPR-C knockout (NPR-C −/ − ) mice to investigate the effects of Ang II (3 mg/kg per day for 3 weeks) on AF susceptibility and atrial function using in vivo electrophysiology, high-resolution optical mapping, patch clamping, and molecular biology. In some experiments, wild-type mice were cotreated with Ang II and the NPR-C agonist cANF (0.07–0.14 mg/kg per day) for 3 weeks. Results: In wild-type mice, Ang II increased susceptibility to AF in association with a prolongation of P-wave duration, increased atrial refractory period, and slowed atrial conduction. These effects were exacerbated in Ang II–treated NPR-C −/− mice. Ang II prolonged action potential duration and reduced action potential upstroke velocity (V max ). These effects were greater in left atrial myocytes from Ang II–treated NPR-C −/− mice. Ang II also increased fibrosis in both atria in wild-type mice, whereas Ang II–treated NPR-C −/− mice exhibited substantially higher fibrosis throughout the atria. Fibrotic responses were associated with changes in expression of profibrotic genes, including TGFβ and TIMP1 . Cotreating wild-type mice with Ang II and the NPR-C agonist cANF dose dependently reduced AF inducibility by preventing some of the Ang II–induced changes in atrial myocyte electrophysiology and preventing fibrosis throughout the atria. Conclusions: NPR-C may represent a new target for the prevention of Ang II–induced AF via protective effects on atrial electrical and structural remodeling.

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Despite the clinical long-term and near-term benefits of lowering cholesterol in, respectively, primary and secondary prevention of ASCVD, cholesterol levels remain under-treated, with many patients not achieving their recommended targets. The present article will review the latest updates on lipid management with emphases on the different classes of cholesterol-lowering agents and their clinical uses.

Pulmonary hypertension (PH) due to left ventricular heart failure (LV-HF) is a disabling and life-threatening disease for which there is currently no single marketed pharmacological agent approved. Despite recent advances in the pathophysiological understanding, there is as yet no prospect of cure, and the majority of patients continue to progress to right ventricular failure and die. There is, therefore an urgent unmet need to identify novel pharmacological agents that will prevent or reverse the increase in pulmonary artery pressures while enhancing cardiac performance in PH due to LV-HF. In the present article, we first focused on the Natriuretic Peptide Receptor type C (NPR-C) based therapeutic strategies aimed at lowering pulmonary artery pressure. Second, we reviewed potential NPR-C therapeutic strategies to reverse or least halt the detrimental effects of diastolic dysfunction and impaired nitic oxide signalling pathways, as well as possibilities for neurohumoral modulation.

The 2014 Ebola outbreak in West Africa, primarily affecting Guinea, Sierra Leone, and Liberia, has exceeded all previous Ebola outbreaks in the number of cases and in international response. Although infections only occur frequently in Western Africa, the virus has the potential to spread globally and is classified as a category A pathogen that could be misused as a bioterrorism agent. This review aims (i) to discuss the latest data to aid our current recommendations for the prevention and control of the Ebola virus infection, (ii) to review its pathophysiology as well as offering insights on the most current data available about Ebola vaccine progress and potential use.

Cardiovascular autonomic neuropathy (CAN) is a serious complication of diabetes mellitus that impairs autonomic regulation of heart rate (HR). This has been attributed to damage to the nerves that modulate spontaneous pacemaker activity in the sinoatrial node (SAN). Our objective was to test the hypothesis that impaired parasympathetic regulation of HR in diabetes is due to reduced responsiveness of the SAN to parasympathetic agonists. We used the Akita mouse model of type 1 diabetes to study the effects of the parasympathetic agonist carbachol (CCh) on SAN function using intracardiac programmed stimulation, high resolution optical mapping and patch-clamping of SAN myocytes. CCh decreased HR by 30% and increased corrected SAN recovery time (cSNRT) by 123% in wildtype mice. In contrast, CCh only decreased HR by 12%, and only increased cSNRT by 37% in Akita mice. These alterations were due to smaller effects of CCh on SAN electrical conduction and spontaneous action potential firing in isolated SAN myocytes. Voltage clamp experiments demonstrate that the acetylcholine-activated K(+) current (IKACh) is reduced in Akita SAN myocytes due to enhanced desensitization and faster deactivation kinetics. These IKACh alterations were normalized by treating Akita SAN myocytes with PI(3,4,5)P3 or an inhibitor of regulator of G-protein signaling 4 (RGS4). There was no difference in the effects of CCh on the hyperpolarization-activated current (If) between wildtype and Akita mice. Our study demonstrates that Akita diabetic mice demonstrate impaired parasympathetic regulation of HR and SAN function due to reduced responses of the SAN to parasympathetic agonists. Our experiments demonstrate a key role for insulin-dependent phosphoinositide 3-kinase (PI3K) signaling in the parasympathetic dysfunction seen in the SAN in diabetes.

The B-type natriuretic peptide (BNP), a member of the family of vasoactive peptides, has emerged as an important diagnostic, prognostic, and therapeutic tool in patients with heart failure (HF). The rapid incorporation into clinical practice of bioassays to BNP concentrations and pharmacological agents that augment the biological actions of this peptide such as nesiritide or vasopeptidase inhibitors has shown the potential for translational research to improve patient care. Despite the indirect evidence in support of a potential benefit from raising BNP, accumulating evidence suggests that simply increasing the amount of circulating BNP does not necessarily confer cardiovascular benefits in patient with HF. Moreover, in experimental HF, the response to treatments targeting specific natriuretic peptide receptors (NPRs) signaling seems to be attenuated. A better understanding of the NPRs signaling in HF would be clinically relevant and thus required, in order to devise strategies to develop novel agents and technologies that directly target this signaling pathway.

Natriuretic peptides (NPs) are critical regulators of the cardiovascular system that are currently viewed as possible therapeutic targets for the treatment of heart disease. Recent work demonstrates potent NP effects on cardiac electrophysiology, including in the sinoatrial node (SAN) and atria. NPs elicit their effects via three NP receptors (NPR-A, NPR-B and NPR-C). Among these receptors, NPR-C is poorly understood. Accordingly, the goal of this study was to determine the effects of NPR-C ablation on cardiac structure and arrhythmogenesis. Cardiac structure and function were assessed in wild-type (NPR-C(+/+)) and NPR-C knockout (NPR-C(-/-)) mice using echocardiography, intracardiac programmed stimulation, patch clamping, high-resolution optical mapping, quantitative polymerase chain reaction and histology. These studies demonstrate that NPR-C(-/-) mice display SAN dysfunction, as indicated by a prolongation (30%) of corrected SAN recovery time, as well as an increased susceptibility to atrial fibrillation (6% in NPR-C(+/+) vs. 47% in NPR-C(-/-)). There were no differences in SAN or atrial action potential morphology in NPR-C(-/-) mice; however, increased atrial arrhythmogenesis in NPR-C(-/-) mice was associated with reductions in SAN (20%) and atrial (15%) conduction velocity, as well as increases in expression and deposition of collagen in the atrial myocardium. No differences were seen in ventricular arrhythmogenesis or fibrosis in NPR-C(-/-) mice. This study demonstrates that loss of NPR-C results in SAN dysfunction and increased susceptibility to atrial arrhythmias in association with structural remodelling and fibrosis in the atrial myocardium. These findings indicate a critical protective role for NPR-C in the heart.

Background The Buckberg index, a diastolic to systolic pressure-time integral ratio, is a resting measure of myocardial oxygen supply and demand. It compares the delivery of oxygen to the heart muscle during diastole to the cardiac workload during systole, calculated through pulse wave analysis. A sub-optimal Buckberg index creates an imbalance which may limit cardiac performance and functional capacity in patients with chronic stable heart failure. Calculating the Buckberg Index Buckberg Index (also known as sub endocardial viability ratio or SEVR) is a pressure-time ratio calculation derived from the pressures in the aorta and left ventricle. The diastolic pressure-time integral (DPTI) indicates sub endocardial blood supply while the systolic pressure-time integral (SPTI) indicates myocardial oxygen demand. Purpose This study was conducted to assess the association between Buckberg index and functional capacity in chronic stable HF patients. Methods 156 clinically stable HF patients, whose weight, condition and medications had not changed in the previous 3 months participated. Buckberg Index was completed using SphygmoCor system. Systolic-to-diastolic pressure shifts were assessed by the systolic and diastolic pressure-time integrals and expressed as a percentage. Patients were then categorized as follows; Buckberg index ≤150% Buckberg index 151–200% Buckberg index ≥201% Functional capacity was evaluated via 6 Minute Walk testing, NYHA Class, 3 day accelerometer measuring daily step count (FitBit) and Kansas City Cardiomyopathy Questionnaire (KCCQ). Results Univariate analysis (table 1) demonstrated statistically significant correlations between Buckberg index and 6 MWT distance, NYHA Class and the KCCQ, but not with daily step count (Fitbit). Although the total number of steps did not correlate with Buckberg Index, those with a BI 150% (6932+/- 4943 steps/day) p ANOVA revealed statistically significant differences among patients grouped (1–3) by Buckberg indexes in relation to 6 MWT ((F (2, 155) = 8.737, p= 0.001)), NYHA Class ((F (2, 156) = 3.407, p= 0.036)), KCCQ Overall summary score ((F (2, 149)=7.516, p= 0.001) and KCCQ Clinical Summary Score ((F (2,146)=11.308, p=0.001)). Conclusion Buckberg index is associated with functional capacity in chronic stable HF patients. We recommend that HF patients are best managed if the Buckberg Index is >150%. The Buckberg Index is a very useful non invasive marker of sub endocardial viability and is associated with improved functional performance and quality of life (QOL). We observe that a Buckberg Index

Background Beta-blockers with additional nitric oxide-mediated vasodilating properties are beneficial in patients with heart failure but its unknown if they are better than non-vasodilating Beta blockers. Aim To compare quality of life in patients with chronic heart failure stabilised on vasodilating and non-vasodilating beta-blockers. Methods and Results 163 patients having chronic stable heart failure for at least 6 months were evaluated according to their treatment with vasodilating or non-vasodilating betablockers. Modified Kansa city cardiomyopathy score was used to assess quality of life. Table 1 summarises patient characteristics, comorbidities and parameters of quality of life in both groups. Conclusion There was no difference in the quality of life of patients on vasodilating and non-vasodilating beta-blockers. While vasodilation should improve quality of life, the lack of difference in our study may reflect that patients may already have maximal vasodilation due to their other therapeutic agents such as ACE or ARBs. This indicates that beta blocker choice is not essential in otherwise optimally treated patients.

Evidence suggests that high-density lipoprotein (HDL) components distinct from cholesterol, such as sphingosine-1-phosphate (S1P), may account for the anti-atherothrombotic effects attributed to this lipoprotein. The current method for the determination of plasma levels of S1P as well as levels associated with HDL particles is still cumbersome an assay method to be worldwide practical. Recently, a simplified protocol based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the sensitive and specific quantification of plasma levels of S1P with good accuracy has been reported. This work utilized a triple quadrupole (QqQ)-based LC-MS/MS system. Here we adapt that method for the determination of plasma levels of S1P using a quadrupole time of flight (Q-Tof) based LC-MS system. Calibration curves were linear in the range of 0.05 to 2 µM. The lower limit of quantification (LOQ) was 0.05 µM. The concentration of S1P in human plasma was determined to be 1 ± 0.09 µM (n = 6). The average accuracy over the stated range of the method was found to be 100 ± 5.9% with precision at the LOQ better than 10% when predicting the calibration standards. The concentration of plasma S1P in the prepared samples was stable for 24 h at room temperature. We have demonstrated the quantification of plasma S1P using Q-Tof based LC-MS with very good sensitivity, accuracy, and precision that can used for future studies in this field.

Non-vitamin K antagonist oral anticoagulants (NOACs) are a major advance for stroke prevention in atrial fibrillation (AF). Use of the vitamin K antagonist (VKA), warfarin, has dropped 40% since 2010 in our institution. There is limited Irish hospital data on NOAC prescribing for stroke prevention. Single centre, retrospective observational cohort study of consecutive AF patients at increased risk of stroke and/or awaiting electrical cardioversion. Data on prescribed NOACs from February 2010 till July 2015 was collected from the electronic inpatient record. Appropriateness of prescriptions was based on CHA2DS2–VASC score and accuracy on individual NOAC SPCs. Potential drug interactions and bleeding risk were also quantified. A total of 348 patients AF and increased risk of stroke (CHA2DS2–VASC score > 1 for men and > 2 for women) were studied. Forty-eight percent were female with a mean age 71 ± 18.6 years, 52% of whom were > 75. Mean CHA2DS2-Vasc and HAS-BLED scores were 4.1 ± 1.8 and 1.4 ± 0.8, respectively. Rivaroxaban, dabigatran and apixaban were prescribed to 154 (54.2%), 106 (34.3%) and 41 (13.2%) patients, respectively. 20.4% had inaccurate prescriptions; 92.9% (n = 65) underdosed and 7.1% (n = 5) on inappropriately higher doses. Neither choice of NOAC, age, history of anaemia, previous bleeding or co-prescribed antiplatelets influenced the accuracy of prescription (p = NS), but decreased renal function appeared to do so (p = 0.05). Our study highlights significant inaccuracies in NOAC prescribing. Patients commenced on NOACs should be assessed and followed up in a multidisciplinary AF clinic to ensure safe and effective prescribing and stroke prevention.

Abnormalities of glucose metabolism in patients with ischaemic heart disease (IHD) are common and are associated with a poor outcome in patients with and without diabetes. Sphingosine-1-phosphate (S1P) is a bioactive lipid which has been shown to increase insulin sensitivity in rodents and to increase myocardial tolerance to ischaemia. In the present review, I explore the relevance of S1P signalling pathway to IHD and abnormalities in glucose tolerance, and its potential as a therapeutic target for patients with abnormal glucose metabolism and IHD.

The FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk) trial [(1)][1], which demonstrated that the addition of the PCSK9 inhibitor evolocumab to statin therapy significantly reduced the risk of atherosclerotic cardiovascular disease (ASCVD) events

In a recent issue of the Journal , Caleyachetty et al. [(1)][1] demonstrated that metabolically healthy obese (MHO) individuals are at higher risk of coronary heart disease, cerebrovascular disease, and heart failure than normal weight metabolically healthy persons. The authors used a metabolic

Background:Presence of macro- and microvascular complications in patients with diabetes mellitus (DM) is not only related to chronic hyperglycemia represented by glycated hemoglobin (HbA1c) but also to acute glycemic fluctuations (glycemic variability, GV). The association between GV and DM complications is not completely clear. Aim of our study was to evaluate GV by MAGE index in patients with type 2 DM and to verify association of MAGE index with presence of macro- and microvascular DM complications.Methods:99 patients with type 2 DM were included in the study. Every patient had done big glycemic profile, from which MAGE index was calculated. Anthropometric measurements, evaluation of HbA1c and fasting plasma glucose (FPG) and assessment for macrovascular (coronary artery disease – CAD; peripheral artery disease – PAD; cerebral stroke – CS) and microvascular (diabetic retinopathy – DR; nephropathy – DN; peripheral neuropathy – DPPN) DM complications were done.Results:Average MAGE index value was 5.15 ± 2.88 mmol/l. We found no significant differences in MAGE index values in subgroups according to presence of neither CAD, CS, PAD nor DR, DN, DPPN. MAGE index value significantly positively correlated with FPG (p < 0.01) and HbA1c (p < 0.001) and negatively with weight (p < 0.05).Conclusion:In our study we failed to show association of MAGE index with presence of macrovascular and microvascular complications in patients with type 2 DM. However, this negative result does not necessarily disprove importance of glycemic variability in pathogenesis of diabetic complications.

The recent Ebola outbreak in Western Africa was the most devastating outbreak witnessed in recent times. There have been remarkable local and international efforts to control the crisis. Ebola Virus Disease is the focus of immense research activity. The progression of events in the region has been evolving swiftly and it is of paramount importance to the medical community to be acquainted with the situation. Over 28000 people were inflicted with the condition, over 11000 have died. Novel data has emerged regarding modes of transmission, providing rationale for recent flare-ups. Similarly, studies on survivors are elucidating the later stages of the disease recovery process. Novel techniques for diagnosis are also discussed. Finally, the current research regarding treatment and vaccine development is reviewed, particularly the implementation of rVSV-ZEBOV vaccination programs.

Patients with acute myocardial infarction or heart failure frequently have abnormalities of glucose metabolism and insulin resistance, both of which are associated with a poor outcome. Sphingolipids are a class of lipids, which play important roles in cellular biological processes including insulin resistance and myocardial ischemia.This review examines the available evidence linking abnormalities in sphingolipids, glucose tolerance and insulin resistance to acute myocardial infarction and heart failure.Pharmacological and genetic activation of enzymes controlling key sphingolipids synthesis, such as sphingosine-1-phosphate, increases insulin sensitivity in rodents and increases myocardial tolerance to ischemia. Major projects are being realized to develop clinical strategies to manipulate sphingolipid metabolism in this clinical settings, with the ultimate goal of increasing insulin sensitivity and augmenting myocardial tolerance to ischemia. Thus, a clear understanding of the sphingolipid-mediated signaling in ischemic heart disease is required to devise strategies to develop novel agents and technologies that directly target this signaling pathway.

We investigated whether plasma long-chain sphingoid base (LCSB) concentrations are altered by transient cardiac ischemia during percutaneous coronary intervention (PCI) in humans and examined the signaling through the sphingosine-1-phosphate (S1P) cascade as a mechanism underlying the S1P cardioprotective effect in cardiac myocytes. Venous samples were collected from either the coronary sinus ( n = 7) or femoral vein ( n = 24) of 31 patients at 1 and 5 min and 12 h, following induction of transient myocardial ischemia during elective PCI. Coronary sinus levels of LCSB were increased by 1,072% at 1 min and 941% at 5 min ( n = 7), while peripheral blood levels of LCSB were increased by 579% at 1 min, 617% at 5 min, and 436% at 12 h ( n = 24). In cultured cardiac myocytes, S1P, sphingosine (SPH), and FTY720, a sphingolipid drug candidate, showed protective effects against CoCl induced hypoxia/ischemic cell injury by reducing lactate dehydrogenase activity. Twenty-five nanomolars of FTY720 significantly increased phospho-Pak1 and phospho-Akt levels by 56 and 65.6% in cells treated with this drug for 15 min. Further experiments demonstrated that FTY720 triggered nitric oxide release from cardiac myocytes is through pertussis toxin-sensitive phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase signaling. In ex vivo hearts, ischemic preconditioning was cardioprotective in wild-type control mice (Pak1f/f), but this protection appeared to be ineffective in cardiomyocyte-specific Pak1 knockout (Pak1cko) hearts. The present study provides the first direct evidence of the behavior of plasma sphingolipids following transient cardiac ischemia with dramatic and early increases in LCSB in humans. We also demonstrated that S1P, SPH, and FTY720 have protective effects against hypoxic/ischemic cell injury, likely a Pak1/Akt1 signaling cascade and nitric oxide release. Further study on a mouse model of cardiac specific deletion of Pak1 demonstrates a crucial role of Pak1 in cardiac protection against ischemia/reperfusion injury.

Complex signal-transduction cascades are known to be involved in regulating cardiomyocyte function, death and survival during acute cardiac ischemia–reperfusion process, but detailed survival signalling pathways are not clear. This review presents and discusses the recent findings bearing upon the evidence on the cardioprotective effect of sphingosine-1-phosphate (S1P) and bradykinin in acute cardiac ischemia–reperfusion and underlying signalling mechanisms, particularly, through activation of P21 activated kinase.

Although bradykinin (BK) is known to exert effects on the myocardium, its intracellular signaling pathways remain poorly understood. Experiments in other cell types indicated that p21-activated kinase-1 (Pak1), a Ser/Thr kinase downstream of small monomeric G proteins, is activated by BK. We previously reported that the expression of active Pak1 in adult cardiac myocytes induced activation of protein phosphatase 2A and dephosphorylation of myofilament proteins (Ke et al. Circ Res 94: 194–200, 2004). In experiments reported here, we tested the hypothesis that BK signals altered protein phosphorylation in adult rat cardiac myocytes through the activation and translocation of Pak1. Treatment of myocytes with BK resulted in the activation of Pak1 as demonstrated by increased autophosphorylation at Thr423 and a diminished striated localization, which is present in the basal state. BK induced dephosphorylation of both cardiac troponin I and phospholamban. Treatment of isolated myocytes with BK also blunted the effect of isoproterenol to enhance peak Ca2+and relaxation of Ca2+transients. Protein phosphatase 2A was demonstrated to associate with both Pak 1 and phospholamban. Our studies indicate a novel signaling mechanism for BK in adult rat cardiac myocytes and support our hypothesis that Pak 1 is a significant regulator of phosphatase activity in the heart.

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Elevated blood lipids may be a major risk factor for CVD. Due to consistent and robust association of higher low-density lipoprotein (LDL)-cholesterol levels with CVD across experimental and epidemiologic studies, therapeutic strategies to decrease risk have focused on LDL-cholesterol reduction as the primary goal. Current medication options for lipid-lowering therapy include statins, bile acid sequestrants, a cholesterol-absorption inhibitor, fibrates, nicotinic acid, and omega-3 fatty acids, which all have various mechanisms of action and pharmacokinetic properties. The most widely prescribed lipid-lowering agents are the HMG-CoA reductase inhibitors, or statins. Since their introduction in the 1980s, statins have emerged as the one of the best-selling medication classes to date, with numerous trials demonstrating powerful efficacy in preventing cardiovascular outcomes (Kapur and Musunuru, 2008 [1]). The statins are commonly used in the treatment of hypercholesterolemia and mixed hyperlipidemia. This chapter focuses on the biochemistry of statins including their structures, pharmacokinetics, and mechanism of actions as well as the potential adverse reactions linked to their clinical uses.

Modulation of Ca(2+) homoeostasis in cardiac myocytes plays a major role in beat-to-beat regulation of heart function. Previous studies suggest that sphingosine-1-phosphate (S1P), a biologically active sphingomyelin metabolite, regulates Ca(2+) handling in cardiac myocytes, but the underlying mechanism is unclear. In the present study, we tested the hypothesis that S1P-induced functional alteration of intracellular Ca(2+) handling includes the L-type calcium channel current (ICa,L) via a signalling pathway involving P21-activated kinase 1 (Pak1). Our results show that, in rat ventricular myocytes, S1P (100 nM) does not affect the basal activity of ICa,L but is able to partially reverse the effect of the β-adrenergic agonist Isoproterenol (ISO, 100 nM) on ICa,L. S1P (25 nM) also significantly prevents ISO (5 nM)-induced Ca(2+) waves and diastolic Ca(2+) release in these cells. Our further molecular characterisation demonstrates that Pak1 activity is increased in myocytes treated with S1P (25 nM) compared with those myocytes without treatment of S1P. By immunoprecipitation we demonstrate that Pak1 and protein phosphatase 2A (PP2A) are associated in ventricular tissue indicating their functional interaction. Thus the results indicate that S1P attenuates β-adrenergic stress-induced alteration of intracellular Ca(2+) release and L-type Ca(2+) channel current at least in part via Pak1-PP2A-mediated signalling.

The B-type natriuretic peptide (BNP), a member of the family of vasoactive peptides, is a potent natriuretic, diuretic, and vasodilatory peptide that contributes to blood pressure and volume homeostasis. These attributes make BNP an ideal drug that could aid in diuresing a fluid-overloaded patient who had poor or worsening renal function. Despite the potential benefits of BNP, accumulating evidence suggests that simply increasing the amount of circulating BNP does not necessarily increase natriuresis in patients with heart failure (HF). Moreover, despite high BNP levels, natriuresis falls when HF progresses from a compensated to a decompensated state, suggesting the emergence of renal resistance to BNP. Although likely multifactorial, several mechanisms have been proposed to explain renal hyporesponsiveness in HF, including, but not limited to, decreased renal BNP availability, down-regulation of natriuretic peptide receptors, and altered BNP intracellular signal transduction pathways. Thus, a better understanding of renal hyporesponsiveness in HF is required to devise strategies to develop novel agents and technologies that directly restore renal BNP efficiency. It is hoped that development of these new therapeutic approaches will serve to limit sodium retention in patients with HF, which may ultimately delay the progression to overt HF.

Summary The B-type natriuretic peptide (BNP) may favour natriuresis and diuresis, making it an ideal drug to aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these has resulted in a better outcome. The current challenge for BNP research in acute HF lies in a failure of concept and reluctance to abandon a demonstrably ineffectual research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP as well as a better integration of basic and clinical science.

Atrial fibrillation (AF) is a major complication in hypertensive heart disease and has been linked to alterations in angiotensin II (AngII) signaling; however, the mechanisms underlying the increase in susceptibility to AF in the presence of AngII are poorly understood. The goal of this study was to characterize changes in atrial electrophysiology in mice treated chronically with AngII. AngII treated mice developed elevated blood pressure and cardiac hypertrophy in comparison to saline treated controls. In intracardiac programmed stimulation studies, 50% of AngII treated mice (n=10) were induced into AF vs. 0% of saline treated mice (P

The sphingosine‐1‐phosphate (S1P) receptor modulator, fingolimod (FTY720), has been used for the treatment of patients with relapsing forms of multiple sclerosis, but atrioventricular (AV) conduction block have been reported in some patients after the first dose. The underlying mechanism of this AV node conduction blockade is still not well‐understood. In this study, we hypothesize that expression of this particular arrhythmia might be related to a direct effect of FTY720 on AV node rather than a parasympathetic mimetic action. We, therefore, investigated the effect of FTY720 on AV nodal, using in vitro rat model preparation, under both basal as well as ischaemia/reperfusion conditions. We first look at the expression pattern of S1P receptors on the AV node using real‐time PCR. Although all three S1P receptor isoforms were expressed in AVN tissues, S1P1 receptor isoform expression level was higher than S1P2 and S1P3. The effect of 25 nM FTY720 on cycle length (CL) was subsequently studied via extracellular potentials recordings. FTY720 caused a mild to moderate prolongation in CL by an average 9% in AVN (n = 10, P

In their recent article, Mora et al1 reported that the on-treatment number of high-density lipoprotein (HDL) particles (HDL-P) may be a better marker of residual risk than HDL cholesterol or apolipoprotein A-I. Although this observation makes a valuable contribution to this field, it is important to emphasize that HDL-P may only give us a small part of the overall HDL picture. Furthermore, some of Mora et al.’s findings must be interpreted with caution because of the potential effect of rosuvastatin on …

PURPOSE OF REVIEW: The absolute level of HDL cholesterol (HDL-C) may not be the only criterion contributing to their antiatherothrombotic effects. This review focuses on evidence in support of the concept that HDL-bound sphingosine-1-phosphate (S1P) plays a role in different HDL atheroprotective properties and may represent a potential target for therapeutic interventions. RECENT FINDINGS: Recent large randomized clinical trials testing the hypothesis of raising HDL-C with niacin and dalcetrapib in statin-treated patients failed to improve cardiovascular outcomes. Emerging evidence suggests that many of the cardioprotective functions of HDL, such as vasodilation, angiogenesis and endothelial barrier function, protection against ischemia/reperfusion injury, and inhibition of atherosclerosis, may be attributable to its S1P cargo. HDL-associated S1P may represent a future therapeutic target. SUMMARY: HDL functionality is affected by its composition and there is evidence to suggest S1P plays a role in some of HDL's functions and atheroprotective properties.