Inflammatory Mediators Drive Adverse Right Ventricular Remodeling and Dysfunction and Serve as Potential Biomarkers

Peri-operative fever and LVAD: SIRS or impaired right ventricular strain?

BACKGROUND

An inflammatory milieu after left ventricular assist device (LVAD) implantation is associated with multi-organ dysfunction and pre-operative heightened inflammatory state is associated with right ventricular failure after LVAD implantation.

METHODS

We performed a retrospective analysis of 30 LVAD patients in our institution within the last 2 years for the development of fever and compared them to 30 non-LVAD open-heart surgery patients.

RESULTS

Our results suggest that patients undergoing LVAD implantation are more likely to develop fever in the immediate post-operative period compared to other open-heart surgeries. This is independent of pharmacological treatment, age, or ethnical background. Females and obese patients were more likely to develop fever.

CONCLUSION

Patients with right ventricular dysfunction, as demonstrated by elevated central venous pressure (CVP), had the strongest correlation with fever development. These results pose the question if there is a systemic inflammatory response-like phenomenon driven by increased right ventricular dysfunction.

Exploring the inflammation-related mechanisms of Lingguizhugan decoction on right ventricular remodeling secondary to pulmonary arterial hypertension based on integrated strategy using UPLC-HRMS, systems biology approach, and experimental validation

BACKGROUND

Pulmonary arterial hypertension (PAH) and the consequent right heart dysfunction persist with high morbidity and mortality, and the mechanisms and pharmacologic interventions for chronic right-sided heart failure (RHF) have not been adequately investigated. Research has shown that prolonged inflammation is critical in precipitating the progression of PAH-associated right heart pathology. Some research demonstrated that Lingguizhugan decoction (LGZGD), as a classical Chinese medicine formula, had beneficial effects in alleviating PAH and RHF, while its underlying mechanisms involved are not fully elucidated.

PURPOSE

Based on that, this study aims to investigate the effects and underlying mechanisms of LGZGD on PAH-induced RHF.

STUDY DESIGN

In this study, we identified the serum constituents and deciphered the potential anti-inflammatory mechanism and crucial components of LGZGD using combined approaches of UPLC-HRMS, transcriptomic analysis, and molecular docking techniques. Finally, we used in vivo experiments to verify the expression of key targets in the monocrotaline (MCT)-induced RHF model and the intervene effect of LGZGD.

RESULTS

Integrated strategies based on UPLC-HRMS and systems biology approach combined with in vivo experimental validation showed that LGZGD could improve right heart fibrosis and dysfunction via regulating diverse inflammatory signaling pathways and the activity of immune cells, including chemokine family CCL2, CXCR4, leukocyte integrins family ITGAL, ITGB2, and M2 macrophage infiltration, as well as lipid peroxidation-associated HMOX1, NOX4, and 4-HNE.

CONCLUSION

The present research demonstrated for the first time that LGZGD might improve PAH-induced RHF through multiple anti-inflammatory signaling and inhibition of ferroptosis, which could provide certain directions for future research in related fields.

Mechanisms and treatment of pulmonary arterial hypertension

Substantial progress has been made in the management of pulmonary arterial hypertension (PAH) in the past 25 years, but the disease remains life-limiting. Established therapies for PAH are mostly limited to symptomatic relief by correcting the imbalance of vasoactive factors. The tyrosine kinase inhibitor imatinib, the first predominantly non-vasodilatory drug to be tested in patients with PAH, improved exercise capacity and pulmonary haemodynamics compared with placebo but at the expense of adverse events such as subdural haematoma. Given that administration by inhalation might reduce the risk of systemic adverse effects, inhaled formulations of tyrosine kinase inhibitors are currently in clinical development. Other novel therapeutic approaches for PAH include suppression of activin receptor type IIA signalling with sotatercept, which has shown substantial efficacy in clinical trials and was approved for use in the USA in 2024, but the long-term safety of the drug remains unclear. Future advances in the management of PAH will focus on right ventricular function and involve deep phenotyping and the development of a personalized medicine approach. In this Review, we summarize the mechanisms underlying PAH, provide an overview of available PAH therapies and their limitations, describe the development of newer, predominantly non-vasodilatory drugs that are currently being tested in phase II or III clinical trials, and discuss future directions for PAH research.

Prognostic Significance of Proteomics-Discovered Circulating Inflammatory Biomarkers in Patients With Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) ultimately leads to right ventricular failure and premature death. The identification of circulating biomarkers with prognostic utility is considered a priority. As chronic inflammation is recognized as key pathogenic driver, we sought to identify inflammation-related circulating proteins that add incremental value to current risk stratification models for long-term survival in patients with PAH.

METHODS AND RESULTS

Plasma levels of 384 inflammatory proteins were measured with the proximity extension assay technology in patients with PAH (n=60) and controls with normal hemodynamics (n=28). Among these, 51 analytes were significantly overexpressed in the plasma of patients with PAH compared with controls. Cox proportional hazard analyses and C-statistics were performed to assess the prognostic value and the incremental prognostic value of differentially expressed proteins. A panel of 6 proteins (CRIM1 [cysteine rich transmembrane bone morphogenetic protein regulator 1], HGF [hepatocyte growth factor], FSTL3 [follistatin-like 3], PLAUR [plasminogen activator, urokinase receptor], CLSTN2 [calsyntenin 2], SPON1 [spondin 1]) were independently associated with death/lung transplantation at the time of PAH diagnosis after adjustment for the 2015 European Society of Cardiology/European Respiratory Society guidelines, the REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) 2.0 risk scores, and the refined 4-strata risk assessment. CRIM1, PLAUR, FSTL3, and SPON1 showed incremental prognostic value on top of the predictive models. As determined by Western blot, FSTL3 and SPON1 were significantly upregulated in the right ventricle of patients with PAH and animal models (monocrotaline-injected and pulmonary artery banding-subjected rats).

CONCLUSIONS

In addition to revealing new actors likely involved in cardiopulmonary remodeling in PAH, our screening identified promising circulating biomarkers to improve risk prediction in PAH, which should be externally confirmed.

Kinin-kallikrein system: New perspectives in heart failure

Heart failure (HF) is a pervasive clinical challenge characterized by compromised cardiac function and reduced quality of life. The kinin-kallikrein system (KSS), a multifaceted peptide cascade, has garnered substantial attention due to its potential role in HF. Through activation of B1 and/or B2 receptors and downstream signaling, kinins modulate various physiological processes, including inflammation, coagulation, pain, blood pressure control, and vascular permeability. Notably, aberrations in KKS components have been linked to HF risk. The elevation of vasodilatory bradykinin (BK) due to kallikrein activity reduces preload and afterload, while concurrently fostering sodium reabsorption inhibition. However, kallikrein's conversion of prorenin to renin leads to angiotensinsII upregulation, resulting in vasoconstriction and fluid retention, alongside increased immune cell activity that fuels inflammation and cardiac remodeling. Importantly, prolonged KKS activation resulting from volume overload and tissue stretch contributes to cardiac collagen loss. The conventional renin-angiotensin-aldosterone system (RAAS) inhibitors used in HF management may inadvertently intensify KKS activity, exacerbating collagen depletion and cardiac remodeling. It is crucial to balance the KKS's role in acute cardiac damage, which may temporarily enhance function and metabolic parameters against its detrimental long-term effects. Thus, KKS blockade emerges as a promising strategy to impede HF progression. By attenuating the link between immune system function and tissue damage, KKS inhibition can potentially reduce cardiac remodeling and alleviate HF symptoms. However, the nuanced roles of BK in various acute conditions necessitate further investigation into the sustained benefits of kallikrein inhibitors in patients with chronic HF.

Mast Cells in Cardiac Remodeling: Focus on the Right Ventricle

In response to various stressors, cardiac chambers undergo structural remodeling. Long-term exposure of the right ventricle (RV) to pressure or volume overload leads to its maladaptive remodeling, associated with RV failure and increased mortality. While left ventricular adverse remodeling is well understood and therapeutic options are available or emerging, RV remodeling remains underexplored, and no specific therapies are currently available. Accumulating evidence implicates the role of mast cells in RV remodeling. Mast cells produce and release numerous inflammatory mediators, growth factors and proteases that can adversely affect cardiac cells, thus contributing to cardiac remodeling. Recent experimental findings suggest that mast cells might represent a potential therapeutic target. This review examines the role of mast cells in cardiac remodeling, with a specific focus on RV remodeling, and explores the potential efficacy of therapeutic interventions targeting mast cells to mitigate adverse RV remodeling.

Tetralogy of Fallot Across the Lifespan: A Focus on the Right Ventricle

Tetralogy of Fallot is a cyanotic congenital heart disease, for which various surgical techniques allow patients to survive to adulthood. Currently, the natural history of corrected tetralogy of Fallot is underlined by progressive right ventricular (RV) failure due to pulmonic regurgitation and other residual lesions. The underlying cellular mechanisms that lead to RV failure from chronic volume overload are characterized by microvascular and mitochondrial dysfunction through various regulatory molecules. On a clinical level, these cardiac alterations are commonly manifested as exercise intolerance. The degree of exercise intolerance can be objectified and aid in prognostication through cardiopulmonary exercise testing. The timing for reintervention on residual lesions contributing to RV volume overload remains controversial; however, interval assessment of cardiac function and volumes by echocardiography and magnetic resonance imaging may be helpful. In patients who develop clinically important RV failure, clinicians should aim to maintain a euvolemic state through the use of diuretics while paying particular attention to preload and kidney function. In patients who develop signs of cardiogenic shock from right heart failure, stabilization through the use of inotropes and pressor is indicated. In special circumstances, the use of mechanical support may be appropriate. However, cardiologists should pay particular attention to residual lesions that may impact the efficacy of the selected device.

Right ventricular failure in pulmonary hypertension: recent insights from experimental models

Right ventricular (RV) function is a critical determinant of the prognosis of patients with pulmonary hypertension (PH). Upon establishment of PH, RV dysfunction develops, leading to a gradual worsening of the condition over time, culminating in RV failure and premature mortality. Despite this understanding, the underlying mechanisms of RV failure remain obscure. As a result, there are currently no approved therapies specifically targeting the right ventricle. One contributing factor to the lack of RV-directed therapies is the complexity of the pathogenesis of RV failure as observed in animal models and clinical studies. In recent years, various research groups have begun utilizing multiple models, including both afterload-dependent and afterload-independent models, to investigate specific targets and pharmacological agents in RV failure. In this review, we examine various animal models of RV failure and the recent advancements made utilizing these models to study the mechanisms of RV failure and the potential efficacy of therapeutic interventions, with the ultimate goal of translating these findings into clinical practice to enhance the management of individuals with PH.

Eleutheroside E from pre-treatment of Acanthopanax senticosus (Rupr.etMaxim.) Harms ameliorates high-altitude-induced heart injury by regulating NLRP3 inflammasome-mediated pyroptosis via NLRP3/caspase-1 pathway

Eleutheroside E, a major natural bioactive compound in Acanthopanax senticosus (Rupr.etMaxim.) Harms, possesses anti-oxidative, anti-fatigue, anti-inflammatory, anti-bacterial and immunoregulatory effects. High-altitude hypobaric hypoxia affects blood flow and oxygen utilisation, resulting in severe heart injury that cannot be reversed, thereby eventually causing or exacerbating high-altitude heart disease and heart failure. The purpose of this study was to determine the cardioprotective effects of eleutheroside E against high-altitude-induced heart injury (HAHI), and to study the mechanisms by which this happens. A hypobaric hypoxia chamber was used in the study to simulate hypobaric hypoxia at the high altitude of 6000 m. 42 male rats were randomly assigned to 6 equal groups and pre-treated with saline, eleutheroside E 100 mg/kg, eleutheroside E 50 mg/kg, or nigericin 4 mg/kg. Eleutheroside E exhibited significant dose-dependent effects on a rat model of HAHI by suppressing inflammation and pyroptosis. Eleutheroside E downregulated the expressions of brain natriuretic peptide (BNP), creatine kinase isoenzymes (CK-MB) and lactic dehydrogenase (LDH). Moreover, The ECG also showed eleutheroside E improved the changes in QT interval, corrected QT interval, QRS interval and heart rate. Eleutheroside E remarkably suppressed the expressions of NLRP3/caspase-1-related proteins and pro-inflammatory factors in heart tissue of the model rats. Nigericin, known as an agonist of NLRP3 inflammasome-mediated pyroptosis, reversed the effects of eleutheroside E. Eleutheroside E prevented HAHI and inhibited inflammation and pyroptosis via the NLRP3/caspase-1 signalling pathway. Taken together, eleutheroside E is a prospective, effective, safe and inexpensive agent that can be used to treat HAHI.

Characterizing the Spatiotemporal Transcriptomic Response of the Right Ventricle to Acute Pressure Overload

This study analyzed microarray data of right ventricular (RV) tissue from rats exposed to pulmonary embolism to understand the initial dynamic transcriptional response to mechanical stress and compare it with experimental pulmonary hypertension (PH) models. The dataset included samples harvested from 55 rats at 11 different time points or RV locations. We performed principal component analysis (PCA) to explore clusters based on spatiotemporal gene expression. Relevant pathways were identified from fast gene set enrichment analysis using PCA coefficients. The RV transcriptomic signature was measured over several time points, ranging from hours to weeks after an acute increase in mechanical stress, and was found to be highly dependent on the severity of the initial insult. Pathways enriched in the RV outflow tracts of rats at 6 weeks after severe PE share many commonalities with experimental PH models, but the transcriptomic signature at the RV apex resembles control tissue. The severity of the initial pressure overload determines the trajectory of the transcriptomic response independent of the final afterload, but this depends on the location where the tissue is biopsied. Chronic RV pressure overload due to PH appears to progress toward similar transcriptomic endpoints.

Therapeutic targeting of mineralocorticoid receptors in pulmonary hypertension: Insights from basic research

Pulmonary hypertension (PH) is characterized by pulmonary vascular remodeling and associated with adverse outcomes. In patients with PH, plasma aldosterone levels are elevated, suggesting that aldosterone and its receptor, the mineralocorticoid receptor (MR), play an important role in the pathophysiology of PH. The MR plays a crucial role in adverse cardiac remodeling in left heart failure. A series of experimental studies from the past few years indicate that MR activation promotes adverse cellular processes that lead to pulmonary vascular remodeling, including endothelial cell apoptosis, smooth muscle cell (SMC) proliferation, pulmonary vascular fibrosis, and inflammation. Accordingly, in vivo studies have demonstrated that pharmacological inhibition or cell-specific deletion of the MR can prevent disease progression and partially reverse established PH phenotypes. In this review, we summarize recent advances in MR signaling in pulmonary vascular remodeling based on preclinical research and discuss the potential, but also the challenges, in bringing MR antagonists (MRAs) into clinical application.

Thoracic Involvement in Systemic Autoimmune Rheumatic Diseases: Pathogenesis and Management

Thoracic involvement is one of the main determinants of morbidity and mortality in patients with autoimmune rheumatic diseases (ARDs), with different prevalence and manifestations according to the underlying disease. Interstitial lung disease (ILD) is the most common pulmonary complication, particularly in patients with systemic sclerosis (SSc), idiopathic inflammatory myopathies (IIMs) and rheumatoid arthritis (RA). Other thoracic manifestations include pulmonary arterial hypertension (PAH), mostly in patients with SSc, airway disease, mainly in RA, and pleural involvement, which is common in systemic lupus erythematosus and RA, but rare in other ARDs.In this review, we summarize and critically discuss the current knowledge on thoracic involvement in ARDs, with emphasis on disease pathogenesis and management. Immunosuppression is the mainstay of therapy, particularly for ARDs-ILD, but it should be reserved to patients with clinically significant disease or at risk of progressive disease. Therefore, a thorough, multidisciplinary assessment to determine disease activity and degree of impairment is required to optimize patient management. Nevertheless, the management of thoracic involvement-particularly ILD-is challenging due to the heterogeneity of disease pathogenesis, the variety of patterns of interstitial pneumonia and the paucity of randomized controlled clinical trials of pharmacological intervention. Further studies are needed to better understand the pathogenesis of these conditions, which in turn is instrumental to the development of more efficacious therapies.

An integrated proteomic and transcriptomic signature of the failing right ventricle in monocrotaline induced pulmonary arterial hypertension in male rats

Aim: Pulmonary arterial hypertension (PAH) is an obstructive pulmonary vasculopathy that results in death from right ventricular failure (RVF). There is limited understanding of the molecular mechanisms of RVF in PAH. Methods: In a PAH-RVF model induced by injection of adult male rats with monocrotaline (MCT; 60 mg/kg), we performed mass spectrometry to identify proteins that change in the RV as a consequence of PAH induced RVF. Bioinformatic analysis was used to integrate our previously published RNA sequencing data from an independent cohort of PAH rats. Results: We identified 1,277 differentially regulated proteins in the RV of MCT rats compared to controls. Integration of MCT RV transcriptome and proteome data sets identified 410 targets that are concordantly regulated at the mRNA and protein levels. Functional analysis of these data revealed enriched functions, including mitochondrial metabolism, cellular respiration, and purine metabolism. We also prioritized 15 highly enriched protein:transcript pairs and confirmed their biological plausibility as contributors to RVF. We demonstrated an overlap of these differentially expressed pairs with data published by independent investigators using multiple PAH models, including the male SU5416-hypoxia model and several male rat strains. Conclusion: Multiomic integration provides a novel view of the molecular phenotype of RVF in PAH which includes dysregulation of pathways involving purine metabolism, mitochondrial function, inflammation, and fibrosis.

Clinical and Molecular Implications of Osteopontin in Heart Failure

The matricellular protein osteopontin modulates cell-matrix interactions during tissue injury and healing. A complex multidomain structure of osteopontin enables it not only to bind diverse cell receptors but also to interact with various partners, including other extracellular matrix proteins, cytokines, and growth factors. Numerous studies have implicated osteopontin in the development and progression of myocardial remodeling in diverse cardiac diseases. Osteopontin influences myocardial remodeling by regulating extracellular matrix production, the activity of matrix metalloproteinases and various growth factors, inflammatory cell recruitment, myofibroblast differentiation, cardiomyocyte apoptosis, and myocardial vascularization. The exploitation of osteopontin loss- and gain-of-function approaches in rodent models provided an opportunity for assessment of the cell- and disease-specific contribution of osteopontin to myocardial remodeling. In this review, we summarize the recent knowledge on osteopontin regulation and its impact on various cardiac diseases, as well as delineate complex disease- and cell-specific roles of osteopontin in cardiac pathologies. We also discuss the current progress of therapeutics targeting osteopontin that may facilitate the development of a novel strategy for heart failure treatment.

Liquiritin inhibits H2 O2 -induced oxidative stress injury in H9c2 cells via the AMPK/SIRT1/NF-κB signaling pathway

Heart failure (HF) is a serious disease with high mortality. Oxidative stress plays a vital role in its occurrence and development. Licorice is commonly used to treat HF in traditional Chinese medicine. Liquiritin, the main ingredient of licorice, has antioxidant and anti-inflammatory properties, but the mechanism against oxidative stress in cardiomyocytes has not been reported. Establishment of oxidative damage model in H9c2 cells by hydrogen peroxide (H₂ O₂ ). Liquiritin (5, 10, 20 μmol/L) could significantly prevent the loss of cell viability and decrease the apoptosis rate. It can reduce the levels of reactive oxygen species (ROS), malonedialdehyde (MDA), lactate dehydrogenase (LDH), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and increase the activity of ATP, superoxidedismutase (SOD), glutathione peroxide (GSH-px), glutathione reductase (GR) and catalase (CAT) to alleviate oxidative stress and inflammation in a dose-dependent manner. Liquiritin was found to be related to AMP-Activated Protein Kinase (AMPK) pathway by molecular docking. Western blotting (WB) and quantitative reverse transcription PCR (RT-qPCR) confirmed that liquiritin could promote AMPKα phosphorylation and sirtuin 1 (SIRT1) protein expression, and inhibit phosphorylation of nuclear factor kappa B p65 (NF-κB p65). Compound C, EX 527, and PDTC can reverse the effects of liquiritin, indicating that its antioxidant effect is achieved by regulating AMPK/SIRT1/NF-κB signaling pathway. PRACTICAL APPLICATIONS: Heart failure is one of the most common cardiovascular diseases, and its treatment remains a worldwide problem. Licorice is a food and dietary supplement that has been used widely in traditional Chinese medicine (TCM). Liquiritin is one of the main active components of licorice, which has antioxidant and anti-inflammatory pharmacological effects. This study revealed the mechanism of licorice against oxidative damage of H9c2 cardiomyocytes, and provided a scientific basis for liquiritin as an antioxidant in the treatment of heart failure.

Proteomic and Metabolomic Analyses of Right Ventricular Failure due to Pulmonary Arterial Hypertension

Right ventricular failure (RVF) is the independent and strongest predictor of mortality in pulmonary arterial hypertension (PAH), but, at present, there are no preventive and therapeutic strategies directly targeting the failing right ventricle (RV). The underlying mechanism of RV hypertrophy (RVH) and dysfunction needs to be explored in depth. In this study, we used myocardial proteomics combined with metabolomics to elucidate potential pathophysiological changes of RV remodeling in a monocrotaline (MCT)-induced PAH rat model. The proteins and metabolites extracted from the RV myocardium were identified using label-free liquid chromatography–tandem mass spectrometry (LC-MS/MS). The bioinformatic analysis indicated that elevated intracellular Ca²⁺ concentrations and inflammation may contribute to myocardial proliferation and contraction, which may be beneficial for maintaining the compensated state of the RV. In the RVF stage, ferroptosis, mitochondrial metabolic shift, and insulin resistance are significantly involved. Dysregulated iron homeostasis, glutathione metabolism, and lipid peroxidation related to ferroptosis may contribute to RV decompensation. In conclusion, we depicted a proteomic and metabolomic profile of the RV myocardium during the progression of MCT-induced PAH, and also provided the insights for potential therapeutic targets facilitating the retardation or reversal of RV dysfunction in PAH.

Procyanidins and Their Therapeutic Potential against Oral Diseases

Procyanidins, as a kind of dietary flavonoid, have excellent pharmacological properties, such as antioxidant, antibacterial, anti-inflammatory and anti-tumor properties, and so they can be used to treat various diseases, including Alzheimer’s disease, diabetes, rheumatoid arthritis, tumors, and obesity. Given the low bioavailability of procyanidins, great efforts have been made in drug delivery systems to address their limited use. Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients’ quality of life indicate a strong need for developing effective therapies. Recent years, plenty of efforts are being made to develop more effective treatments. Therefore, this review summarized the latest researches on versatile effects and enhanced bioavailability of procyanidins resulting from innovative drug delivery systems, particularly focused on its potential against oral diseases.

Effect of the number of parity on right heart chamber quantification

INTRODUCTION

Pregnancy is a process that can cause several physiologic changes to the cardiovascular system such as ventricular hypertrophy and dilation of cardiac chambers. Although there are studies about pregnancy-related changes in echocardiographic examination; there is no data about the long-term effects of parity on these alterations. Therefore, we evaluated the long-term effect of pregnancy on right ventricular (RV) dilation and RV hypertrophy and their relation to the parity number.

METHODS

This prospective study included a total of 600 women (200 consecutive women who had no parity, 200 women who had a parity number of 1 to 4 and 200 women who had a parity number of more than 4). Right chambers' measurements were compared between the groups.

RESULTS

In echocardiographic analysis, RV and right atrial dimensions and areas and RV wall thickness were higher in parous women. On the other hand, RV systolic function parameters were significantly lower in parous women. These significant changes showed a gradual increase or decrease by increasing parity number. By multivariate hierarchical logistic regression analysis, the four independent factors that increased the risk of RV dilation were age (OR: 1.16 CI: 1.10-1.20), body mass index (OR: 1.05, CI: 1.02-1.08), smoking (OR: 1.87, CI: 1.28-4.02), and giving a birth (OR: 3.94 CI: 1.82-8.81). There was also independent relationship between the number of parity and RV hypertrophy even after adjustment for several confounders.

CONCLUSION

Pregnancy-related physiological changes mostly resolve after delivery. This study about long-term effects of pregnancy on RV has demonstrated that there is a significant relation between the number of parity and either RV dilation or RV hypertrophy. Each parity had also additive effect on these changes.

Clinical and radiological characteristics of acute pulmonary embolus in relation to 28-day and 6-month mortality

Background

Patients with acute pulmonary embolism (PE) exhibit a wide spectrum of clinical and laboratory features when presenting to hospital and pathophysiologic mechanisms differentiating low-risk and high-risk PE are poorly understood.

Objectives

To investigate the prognostic value of clinical, laboratory and radiological information that is available within routine tests undertaken for patients with acute PE.

Methods

Electronic patient records (EPR) of patients who underwent Computed Tomography Pulmonary Angiogram (CTPA) scan for the investigation of acute PE during 6-month period (01.01.2016–30.06.2016) were examined. Data was gathered from EPR for patients that met inclusion criteria and all CTPA scans were re-evaluated. Biochemical thresholds of low-grade and high-grade inflammation, serum CRP >10mg/L and >150mg/L and serum albumin concentrations <35g/L and <25 g/L, were combined in the Glasgow Prognostic Score (GPS) and peri-operative Glasgow Prognostic Score (poGPS) respectively. Neutrophil Lymphocyte ratio (NLR) was also calculated. Pulmonary Embolus Severity Index score was calculated.

Results

Of the total CTPA reports (n = 2129) examined, 245 patients were eligible for inclusion. Of these, 20 (8%) patients had died at 28-days and 43 (18%) at 6-months. Of the 197 non-cancer related presentations, 28-day and 6-month mortality were 3% and 8% respectively. Of the 48 cancer related presentations, 28-day and 6-month mortality were 29% and 58% respectively. On univariate analysis, age ≥65 years (p<0.01), PESI score ≥100(p = <0.001), NLR ≥3(p<0.001) and Coronary Artery Calcification (CAC) score ≥ 6 (p<0.001) were associated with higher 28-day and 6-month mortality. PESI score ≥100 (OR 5.2, 95% CI: 1.1, 24.2, P <0.05), poGPS ≥1 (OR 2.5, 95% CI: 1.2–5.0, P = 0.01) and NLR ≥3 (OR 3.7, 95% CI: 1.0–3.4, P <0.05) remained independently associated with 28-day mortality. On multivariate binary logistic regression analysis of factors associated with 6-month mortality, PESI score ≥100 (OR 6.2, 95% CI: 2.3–17.0, p<0.001) and coronary artery calcification score ≥6 (OR 2.3, 95% CI: 1.1–4.8, p = 0.030) remained independently associated with death at 6-months. When patients who had an underlying cancer diagnosis were excluded from the analysis only GPS≥1 remained independently associated with 6-month mortality (OR 5.0, 95% CI 1.2–22.0, p<0.05).

Conclusion

PESI score >100, poGPS≥1, NLR ≥3 and CAC score ≥6 were associated with 28-day and 6-month mortality. PESI score ≥100, poGPS≥1 and NLR ≥3 remained independently associated with 28-day mortality. PESI score ≥100 and CAC score ≥6 remained independently associated with 6-month mortality. When patients with underlying cancer were excluded from the analysis, GPS≥1 remained independently associated with 6-month mortality. The role of the systemic inflammatory response (SIR) in determining treatment and prognosis requires further study. Routine reporting of CAC scores in CTPA scans for acute PE may have a role in aiding clinical decision-making regarding treatment and prognosis.

Novel Therapeutic Targets for the Treatment of Right Ventricular Remodeling: Insights from the Pulmonary Artery Banding Model

Right ventricular (RV) function is the main determinant of the outcome of patients with pulmonary hypertension (PH). RV dysfunction develops gradually and worsens progressively over the course of PH, resulting in RV failure and premature death. Currently, approved therapies for the treatment of left ventricular failure are not established for the RV. Furthermore, the direct effects of specific vasoactive drugs for treatment of pulmonary arterial hypertension (PAH, Group 1 of PH) on RV are not fully investigated. Pulmonary artery banding (PAB) allows to study the pathogenesis of RV failure solely, thereby testing potential therapies independently of pulmonary vascular changes. This review aims to discuss recent studies of the mechanisms of RV remodeling and RV-directed therapies based on the PAB model.

Interventricular Differences of Signaling Pathways-Mediated Regulation of Cardiomyocyte Function in Response to High Oxidative Stress in the Post-Ischemic Failing Rat Heart

Standard heart failure (HF) therapies have failed to improve cardiac function or survival in HF patients with right ventricular (RV) dysfunction suggesting a divergence in the molecular mechanisms of RV vs. left ventricular (LV) failure. Here we aimed to investigate interventricular differences in sarcomeric regulation and function in experimental myocardial infarction (MI)-induced HF with reduced LV ejection fraction (HFrEF). MI was induced by LAD ligation in Sprague-Dawley male rats. Sham-operated animals served as controls. Eight weeks after intervention, post-ischemic HFrEF and Sham animals were euthanized. Heart tissue samples were deep-frozen stored (n = 3-5 heart/group) for ELISA, kinase activity assays, passive stiffness and Ca²⁺-sensitivity measurements on isolated cardiomyocytes, phospho-specific Western blot, and PAGE of contractile proteins, as well as for collagen gene expressions. Markers of oxidative stress and inflammation showed interventricular differences in post-ischemic rats: TGF-β1, lipid peroxidation, and 3-nitrotyrosine levels were higher in the LV than RV, while hydrogen peroxide, VCAM-1, TNFα, and TGF-β1 were increased in both ventricles. In addition, nitric oxide (NO) level was significantly decreased, while FN-1 level was significantly increased only in the LV, but both were unchanged in RV. CaMKII activity showed an 81.6% increase in the LV, in contrast to a 38.6% decrease in the RV of HFrEF rats. Cardiomyocyte passive stiffness was higher in the HFrEF compared to the Sham group as evident from significantly steeper F_passive vs. sarcomere length relationships. In vitro treatment with CaMKIIδ, however, restored cardiomyocyte passive stiffness only in the HFrEF RV, but had no effect in the HFrEF LV. PKG activity was lower in both ventricles in the HFrEF compared to the Sham group. In vitro PKG administration decreased HFrEF cardiomyocyte passive stiffness; however, the effect was more pronounced in the HFrEF LV than HFrEF RV. In line with this, we observed distinct changes of titin site-specific phosphorylation in the RV vs. LV of post-ischemic rats, which may explain divergent cardiomyocyte stiffness modulation observed. Finally, Ca²⁺-sensitivity of RV cardiomyocytes was unchanged, while LV cardiomyocytes showed increased Ca²⁺-sensitivity in the HFrEF group. This could be explained by decreased Ser-282 phosphorylation of cMyBP-C by 44.5% in the RV, but without any alteration in the LV, while Ser-23/24 phosphorylation of cTnI was decreased in both ventricles in the HFrEF vs. the Sham group. Our data pointed to distinct signaling pathways-mediated phosphorylations of sarcomeric proteins for the RV and LV of the post-ischemic failing rat heart. These results implicate divergent responses for oxidative stress and open a new avenue in targeting the RV independently of the LV.

Targeted proteomics of right heart adaptation to pulmonary arterial hypertension

No prior proteomic screening study has centred on the right ventricle (RV) in pulmonary arterial hypertension (PAH). This study investigates the circulating proteomic profile associated with right heart maladaptive phenotype (RHMP) in PAH.Plasma proteomic profiling was performed using multiplex immunoassay in 121 (discovery cohort) and 76 (validation cohort) PAH patients. The association between proteomic markers and RHMP, defined by the Mayo right heart score (combining RV strain, New York Heart Association (NYHA) class and N-terminal pro-brain natriuretic peptide (NT-proBNP)) and Stanford score (RV end-systolic remodelling index, NYHA class and NT-proBNP), was assessed by partial least squares regression. Biomarker expression was measured in RV samples from PAH patients and controls, and pulmonary artery banding (PAB) mice.High levels of hepatocyte growth factor (HGF), stem cell growth factor-β, nerve growth factor and stromal derived factor-1 were associated with worse Mayo and Stanford scores independently from pulmonary resistance or pressure in both cohorts (the validation cohort had more severe disease features: lower cardiac index and higher NT-proBNP). In both cohorts, HGF added value to the REVEAL score in the prediction of death, transplant or hospitalisation at 3 years. RV expression levels of HGF and its receptor c-Met were higher in end-stage PAH patients than controls, and in PAB mice than shams.High plasma HGF levels are associated with RHMP and predictive of 3-year clinical worsening. Both HGF and c-Met RV expression levels are increased in PAH. Assessing plasma HGF levels might identify patients at risk of heart failure who warrant closer follow-up and intensified therapy.

Sildenafil improves right ventricular remodelling in monocrotaline-induced rats by decreasing myocardial apoptosis and activating peroxisome proliferator-activated receptors

OBJECTIVES

To assess the effect of sildenafil on monocrotaline-induced right ventricular (RV) remodeling and investigate the possible mechanism.

METHODS

Rats were subcutaneously injected with monocrotaline to establish an RV remodeling model and then administered sildenafil (25 mg/kg) from days 1 to 28. After 28 days of administration, the RV systolic pressure and the RV hypertrophy index (RVHI) were measured. The morphology of the right ventricle was observed by H&E staining. The ultrastructure of the right ventricle was observed using a transmission electron microscope. The myocardial apoptosis of the right ventricle was evaluated by TUNEL staining. The protein expression of apoptosis-related proteins and PPARs were examined by western blotting.

KEY FINDINGS

The results indicated that sildenafil decreased the RV systolic pressure and RVHI, and improved the microstructure and ultrastructure of the right ventricle in monocrotaline-induced rats. In addition, sildenafil suppressed myocardial apoptosis and promoted the protein expression of PPARs of the right ventricle in monocrotaline-induced rats.

CONCLUSION

Sildenafil inhibits RV remodeling in monocrotaline-induced rats, which might be partially mediated by reducing myocardial apoptosis and activating PPARs.

Transcriptomic Analysis of Right Ventricular Remodeling in Two Rat Models of Pulmonary Hypertension: Identification and Validation of Epithelial-to-Mesenchymal Transition in Human Right Ventricular Failure

BACKGROUND

Right ventricular (RV) dysfunction is a significant prognostic determinant of morbidity and mortality in pulmonary arterial hypertension (PAH). Despite the importance of RV function in PAH, the underlying molecular mechanisms of RV dysfunction secondary to PAH remain unclear. We aim to identify and compare molecular determinants of RV failure using RNA sequencing of RV tissue from 2 clinically relevant animal models of PAH.

METHODS

We performed RNA sequencing on RV from rats treated with monocrotaline or Sugen with hypoxia/normoxia. PAH and RV failure were confirmed by catheterization and echocardiography. We validated the RV transcriptome results using quantitative real-time polymerase chain reaction, immunofluorescence, and Western blot. Immunohistochemistry and immunofluorescence were performed on human RV tissue from control (n=3) and PAH-induced RV failure patients (n=5).

RESULTS

We identified similar transcriptomic profiles of RV from monocrotaline- and Sugen with hypoxia-induced RV failure. Pathway analysis showed genes enriched in epithelial-to-mesenchymal transition, inflammation, and metabolism. Histological staining of human RV tissue from patients with RV failure secondary to PAH revealed significant RV fibrosis and endothelial-to-mesenchymal transition, as well as elevated cellular communication network factor 2 (top gene implicated in epithelial-to-mesenchymal transition/endothelial-to-mesenchymal transition) expression in perivascular areas compared with normal RV.

CONCLUSIONS

Transcriptomic signature of RV failure in monocrotaline and Sugen with hypoxia models showed similar gene expressions and biological pathways. We provide translational relevance of this transcriptomic signature using RV from patients with PAH to demonstrate evidence of epithelial-to-mesenchymal transition/endothelial-to-mesenchymal transition and protein expression of cellular communication network factor 2 (CTGF [connective tissue growth factor]). Targeting specific molecular mechanisms responsible for RV failure in monocrotaline and Sugen with hypoxia models may identify novel therapeutic strategies for PAH-associated RV failure.

Inflammation in Heart Failure: JACC State-of-the-Art Review

It has long been observed that heart failure (HF) is associated with measures of systemic inflammation. In recent years, there have been significant advancements in our understanding of how inflammation contributes to the pathogenesis and progression of HF. However, although numerous studies have validated the association between measures of inflammation and HF severity and prognosis, clinical trials of anti-inflammatory therapies have proven mostly unsuccessful. On this backdrop emerges the yet unmet goal of targeting precise phenotypes within the syndrome of HF; if such precise definitions can be realized, and with better understanding of the roles played by specific inflammatory mediators, the expectation is that targeted anti-inflammatory therapies may improve prognosis in patients whose HF is driven by inflammatory pathobiology. Here, the authors describe mechanistic links between inflammation and HF, discuss traditional and novel inflammatory biomarkers, and summarize the latest evidence from clinical trials of anti-inflammatory therapies.

Hypoxia and its preconditioning on cardiac and vascular remodelling in experimental animals

Since oxygen (O₂) is indispensable for mammalian life, every cell in the body is endowed with mechanisms to detect and to respond to changes in the O₂ levels in the microenvironment. The heart and the brain are the two most vital, life-supporting organs requiring a continuous supply of O₂ to sustain their high metabolic rate. On being challenged with hypoxia, maintenance of O₂ supply to these organs even at the cost of others becomes a priority. This review describes the cardiovascular, skeletal muscle vascular, pulmonary vascular and cerebrovascular remodelling in face of chronic mild hypoxia exposure and the underlying mechanisms, with special reference to the role of oxidative stress, hypoxia signalling, autonomic nervous mechanisms. The significance of the normalized wall index (NWI) in assessing the remodelling of the vessels particularly of the intramyocardial coronary artery has been underscored. The review also highlights the basic concepts of hypoxic preconditioning and the subsequent protection of the brain against an acute ischemic insult in preclinical studies hinting towards its possible therapeutic potential in the management of ischemic stroke.

Treatment Targets for Right Ventricular Dysfunction in Pulmonary Arterial Hypertension

Right ventricle (RV) dysfunction is the strongest predictor of mortality in pulmonary arterial hypertension (PAH), but, at present, there are no therapies directly targeting the failing RV. Although there are shared molecular mechanisms in both RV and left ventricle (LV) dysfunction, there are important differences between the 2 ventricles that may allow for the development of RV-enhancing or RV-directed therapies. In this review, we discuss the current understandings of the dysregulated pathways that promote RV dysfunction, highlight RV-enriched or RV-specific pathways that may be of particular therapeutic value, and summarize recent and ongoing clinical trials that are investigating RV function in PAH. It is hoped that development of RV-targeted therapies will improve quality of life and enhance survival for this deadly disease.

Genetic Deficiency and Pharmacological Stabilization of Mast Cells Ameliorate Pressure Overload-Induced Maladaptive Right Ventricular Remodeling in Mice

Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (Kit^W/Kit^W-v) mice and their mast cell-sufficient littermate controls (MC^+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC^+/+ mice. In PAB Kit^W/Kit^W-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart.

Gamut of cardiac manifestations and complications of COVID-19: a contemporary review

COVID-19 has posed an extraordinary burden on health and the economy worldwide. Patients with cardiovascular diseases are more likely to have severe illness due to COVID-19 and are at increased risk for complications and mortality. We performed a narrative literature review to assess the burden of COVID-19 and cardiovascular morbidity and mortality. Myocardial injury has been reported in 20%-30% of patients hospitalized due to COVID-19 and is associated with a worse prognosis and high mortality (~50%-60%). Proposed mechanisms of myocardial injury include inflammation within the myocardium (due to direct viral infection or cytokine storm), endotheliitis, coronary vasculitis, myocarditis, demand ischemia, plaque destabilization and right ventricular failure. The right ventricle is particularly vulnerable to injury and failure in COVID-19-infected patients, given the hypoxic pulmonary vasoconstriction, pulmonary microthrombi or pulmonary embolism. Echocardiography is an effective and accessible tool to evaluate left and right ventricular functions and risk stratify patients with COVID-19 infection. Cardiac MRI has detected and characterized myocardial injury, with changes compatible with other inflammatory cardiomyopathies. The long-term consequences of these inflammatory changes are unknown, but accumulating data will provide insight regarding the longitudinal impact of COVID-19 infection on cardiovascular morbidity and mortality.

Emerging therapies for right ventricular dysfunction and failure

Therapeutic options for right ventricular (RV) dysfunction and failure are strongly limited. Right heart failure (RHF) has been mostly addressed in the context of pulmonary arterial hypertension (PAH), where it is not possible to discern pulmonary vascular- and RV-directed effects of therapeutic approaches. In part, opposing pathomechanisms in RV and pulmonary vasculature, i.e., regarding apoptosis, angiogenesis and proliferation, complicate addressing RHF in PAH. Therapy effective for left heart failure is not applicable to RHF, e.g., inhibition of adrenoceptor signaling and of the renin-angiotensin system had no or only limited success. A number of experimental studies employing animal models for PAH or RV dysfunction or failure have identified beneficial effects of novel pharmacological agents, with most promising results obtained with modulators of metabolism and reactive oxygen species or inflammation, respectively. In addition, established PAH agents, in particular phosphodiesterase-5 inhibitors and soluble guanylate cyclase stimulators, may directly address RV integrity. Promising results are furthermore derived with microRNA (miRNA) and long non-coding RNA (lncRNA) blocking or mimetic strategies, which can target microvascular rarefaction, inflammation, metabolism or fibrotic and hypertrophic remodeling in the dysfunctional RV. Likewise, pre-clinical data demonstrate that cell-based therapies using stem or progenitor cells have beneficial effects on the RV, mainly by improving the microvascular system, however clinical success will largely depend on delivery routes. A particular option for PAH is targeted denervation of the pulmonary vasculature, given the sympathetic overdrive in PAH patients. Finally, acute and durable mechanical circulatory support are available for the right heart, which however has been tested mostly in RHF with concomitant left heart disease. Here, we aim to review current pharmacological, RNA- and cell-based therapeutic options and their potential to directly target the RV and to review available data for pulmonary artery denervation and mechanical circulatory support.

Oxidative Stress, Kinase Activity and Inflammatory Implications in Right Ventricular Hypertrophy and Heart Failure under Hypobaric Hypoxia

High altitude (hypobaric hypoxia) triggers several mechanisms to compensate for the decrease in oxygen bioavailability. One of them is pulmonary artery vasoconstriction and its subsequent pulmonary arterial remodeling. These changes can lead to pulmonary hypertension and the development of right ventricular hypertrophy (RVH), right heart failure (RHF) and, ultimately to death. The aim of this review is to describe the most recent molecular pathways involved in the above conditions under this type of hypobaric hypoxia, including oxidative stress, inflammation, protein kinases activation and fibrosis, and the current therapeutic approaches for these conditions. This review also includes the current knowledge of long-term chronic intermittent hypobaric hypoxia. Furthermore, this review highlights the signaling pathways related to oxidative stress (Nox-derived O₂^.- and H₂O₂), protein kinase (ERK5, p38α and PKCα) activation, inflammatory molecules (IL-1β, IL-6, TNF-α and NF-kB) and hypoxia condition (HIF-1α). On the other hand, recent therapeutic approaches have focused on abolishing hypoxia-induced RVH and RHF via attenuation of oxidative stress and inflammatory (IL-1β, MCP-1, SDF-1 and CXCR-4) pathways through phytotherapy and pharmacological trials. Nevertheless, further studies are necessary.

Adaptive and innate immune mechanisms in cardiac fibrosis complicating pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a syndrome diagnosed by increased mean pulmonary artery (PA) pressure and resistance and normal pulmonary capillary wedge pressure. PAH is characterized pathologically by distal pulmonary artery remodeling, increased pulmonary vascular resistance, and plexiform lesions (PLs). Right ventricular fibrosis and hypertrophy, leading to right ventricular failure, are the main determinants of mortality in PAH. Recent work suggests that right ventricular fibrosis results from resident cardiac fibroblast activation and conversion to myofibroblasts, leading to replacement of contractile cardiomyocytes with nondistensible tissue incapable of conductivity or contractility. However, the origins, triggers, and consequences of myofibroblast expansion and its pathophysiological relationship with PAH are unclear. Recent advances indicate that signals generated by adaptive and innate immune cells may play a role in right ventricular fibrosis and remodeling. This review summarizes recent insights into the mechanisms by which adaptive and innate immune signals participate in the transition of cardiac fibroblasts to activated myofibroblasts and highlights the existing gaps of knowledge as relates to the development of right ventricular fibrosis.

In the eye of the storm: the right ventricle in COVID-19

The corona virus disease of 2019 pandemic caused by the SARS-CoV-2 virus continues to inflict significant morbidity and mortality around the globe. A variety of cardiovascular presentations of SARS-CoV-2 infection have been described so far. However, the impact of SARS-CoV-2 on the right ventricle is largely unknown. Due to its pathophysiologic relevance, the right ventricle finds itself in the eye of the storm of corona virus disease of 2019, placing it at higher risk of failure. Increased afterload from acute respiratory distress syndrome and pulmonary embolism, negative inotropic effects of cytokines, and direct angiotensin converting enzyme 2-mediated cardiac injury from SARS-CoV-2 are potential mechanisms of right ventricle dysfunction in corona virus disease of 2019. Early detection and treatment of right ventricle dysfunction may lead to decreased mortality and improved patient outcomes in corona virus disease of 2019.

β3 adrenergic receptor antagonist SR59230A exerts beneficial effects on right ventricular performance in monocrotaline-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease with a high mortality rate. Previous studies have revealed the important function of the β3 adrenergic receptor (β3-AR) in cardiovascular diseases, and the potential beneficial effects of numerous β3-AR agonists on pulmonary vasodilation. Conversely, a number of studies have proposed that the antagonism of β3-AR may prevent heart failure. The present study aimed to investigate the functional involvement of β3-AR and the effects of the β3-AR antagonist, SR59230A, in PAH and subsequent heart failure. A rat PAH model was established by the subcutaneous injection of monocrotaline (MCT), and the rats were randomly assigned to groups receiving four weeks of SR59230A treatment or the vehicle control. SR59230A treatment significantly improved right ventricular function in PAH in vivo compared with the vehicle control (P<0.001). Additionally, the expression level of β3-AR was significantly upregulated in the lung and heart tissues of PAH rats compared with the sham group (P<0.01), and SR59230A treatment inhibited this increase in the lung (P<0.05), but not the heart. Specifically, SR59230A suppressed the elevated expression of endothelial nitric oxide and alleviated inflammatory infiltration to the lung under PAH conditions. These results are, to the best of our knowledge, the first to reveal that SR59230A exerts beneficial effects on right ventricular performance in rats with MCT-induced PAH. Furthermore, blocking β3-AR with SR59230A may alleviate the structural changes and inflammatory infiltration to the lung as a result of reduced oxidative stress.

Associations between IL-6 and Echo-Parameters in Patients with Early Onset Coronary Artery Disease

BACKGROUND

Over the last two decades, many studies have investigated the association between interleukin 6 (IL-6) and pathogenesis and progression of coronary artery disease (CAD). Patients with CAD manifested at a young age are a particularly interesting group. They differ from older patients, not only in terms of the severity of coronary artery atherosclerosis, but also risk factor profiles, short- and long-term prognosis after myocardial infarction (MI). The role of IL-6 in younger patients with CAD is less well-known. Therefore, our study aimed to analyze the relationship between IL-6 level and other inflammations, atherosclerosis, and cardiac function parameters in early onset CAD patients.

METHODS

The study covered 100 patients with early onset CAD and a group of 50 healthy participants. Plasma levels of IL-6 and basic biochemical parameters, anthropometric, echocardiographic, and arteries Doppler ultrasound measurements were performed.

RESULTS

We did not observe a significant difference in IL-6 concentration in plasma between patients with early onset CAD and a control group, but IL-6 level was negatively correlated with echocardiographic measurements of ascending aorta diameter, left ventricular shortening fraction, and right ventricular end-diastolic diameter in our patients.

CONCLUSIONS

In patients with early onset CAD, plasma IL-6 level is associated with other inflammation parameters and with cardiac function, potentially contributing to right ventricular remodeling and left ventricular systolic dysfunction. This suggests possible prognostic benefits of long-time observation of IL-6 level after the acute coronary syndrome.

The role of chemokines and chemokine receptors in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by progressive pulmonary artery remodelling leading to increased right ventricular pressure overload, which results in right heart failure and premature death. Inflammation plays a central role in the development of PAH, and the recruitment and function of immune cells are tightly regulated by chemotactic cytokines called chemokines. A number of studies have shown that the development and progression of PAH are associated with the dysregulated expression of several chemokines and chemokine receptors in the pulmonary vasculature. Moreover, some chemokines are differentially regulated in the pressure-overloaded right ventricle. Recent studies have tested the efficacy of pharmacological agents targeting several chemokines and chemokine receptors for their effects on the development of PAH, suggesting that these receptors could serve as useful therapeutic targets. In this review, we provide recent insights into the role of chemokines and chemokine receptors in PAH and RV remodelling and the opportunities and roadblocks in targeting them. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Lipocalin-2 Predicts Long-Term Outcome of Normotensive Patients with Acute Pulmonary Embolism

Normotensive patients with acute pulmonary embolism (APE) are accompanied by heterogeneously adverse events. Responding to tissue injury, lipocalin-2 (LCN-2) is elevated in experimental APE model and associated with short-term prognosis. However, the prognostic value of LCN-2 in normotensive patients with APE for long-term major adverse events (MAEs) remains unknown. We evaluated the association of plasma LCN-2 levels with the median 467-day outcome in 170 normotensive patients with APE. We also assessed whether LCN-2 could improve risk stratification. MAEs consisted of mortality or recurrence of venous thromboembolism. During follow-up, 17 (10%) patients suffered from MAEs. These patients had higher LCN-2 levels compared with patients without MAEs (median: 13.97 vs. 8.55 ng/ml, P = 0.01). The proportion of MAEs in the intermediate-low-risk group (14.0%) was higher than that in the intermediate-high-risk group (5.3%). LCN-2 levels independently had prognostic value for MAEs in overall (HR = 3.40, 95% CI 1.46-7.90) and intermediate-risk group (HR = 3.88, 95% CI 1.63-9.23). LCN-2 also showed incremental value in overall (ΔC-index: 0.13, 95% CI 0.02-0.24; category-based NRI = 0.25, 95% CI 0.07-0.42) and intermediate-risk patients (ΔC-index: 0.13, 95% CI 0.05-0.31; category-based NRI = 0.44, 95% CI 0.24-0.65). Adding LCN-2 (cut-off value = 11 ng/ml) to the current risk algorithm improved MAEs of intermediate-risk reclassification (intermediate-high vs. intermediate-low = 25.6% vs. 6.0%, P = 0.002). Elevated plasma LCN-2 levels predict long-term MAEs among normotensive patients with APE. LCN-2 might be a useful biomarker for risk stratification in the intermediate-risk group.

Pulmonary arterial hypertension in connective tissue disorders: Pathophysiology and treatment

IMPACT STATEMENT

Our article focuses on the pathogenesis and treatment of CTD-PAH. In the latest ESC/ESR guidelines for PAH, the authors underline that although CTD-PAH should follow the same treatment protocol as idiopathic PAH, the therapeutic approach is more complex and difficult in the former. This review throws light on several peculiar aspects of CTD-PAH and the latest findings in the pathogenesis, namely, the role of inflammation in the maladaptive right ventricle remodeling in SSc-PAH where immunosuppressants are classically believed to be ineffective. Furthermore, we discuss the major critical points in the therapy of CTD-PAH which is one of the strengths of our article. To the best of our knowledge, there are no other reviews that exclusively focus on the pathogenesis and treatment of CTD-PAH patients, with an emphasis on the more critical issues. Thus, it is our contention that our work would be of interest to the readers.

The Role of G Protein-Coupled Receptors in the Right Ventricle in Pulmonary Hypertension

Pressure overload of the right ventricle (RV) in pulmonary arterial hypertension (PAH) leads to RV remodeling and failure, an important determinant of outcome in patients with PAH. Several G protein-coupled receptors (GPCRs) are differentially regulated in the RV myocardium, contributing to the pathogenesis of RV adverse remodeling and dysfunction. Many pharmacological agents that target GPCRs have been demonstrated to result in beneficial effects on left ventricular (LV) failure, such as beta-adrenergic receptor and angiotensin receptor antagonists. However, the role of such drugs on RV remodeling and performance is not known at this time. Moreover, many of these same receptors are also expressed in the pulmonary vasculature, which could result in complex effects in PAH. This manuscript reviews the role of GPCRs in the RV remodeling and dysfunction and discusses activating and blocking GPCR signaling to potentially attenuate remodeling while promoting improvements of RV function in PAH.

Transcriptomic Signature of Right Ventricular Failure in Experimental Pulmonary Arterial Hypertension: Deep Sequencing Demonstrates Mitochondrial, Fibrotic, Inflammatory and Angiogenic Abnormalities

Right ventricular failure (RVF) remains the leading cause of death in pulmonary arterial hypertension (PAH). We investigated the transcriptomic signature of RVF in hemodynamically well-phenotyped monocrotaline (MCT)-treated, male, Sprague-Dawley rats with severe PAH and decompensated RVF (increased right ventricular (RV) end diastolic volume (EDV), decreased cardiac output (CO), tricuspid annular plane systolic excursion (TAPSE) and ventricular-arterial decoupling). RNA sequencing revealed 2547 differentially regulated transcripts in MCT-RVF RVs. Multiple enriched gene ontology (GO) terms converged on mitochondria/metabolism, fibrosis, inflammation, and angiogenesis. The mitochondrial transcriptomic pathway is the most affected in RVF, with 413 dysregulated genes. Downregulated genes included TFAM (−0.45-fold), suggesting impaired mitochondrial biogenesis, CYP2E1 (−3.8-fold), a monooxygenase which when downregulated increases oxidative stress, dehydrogenase/reductase 7C (DHRS7C) (−2.8-fold), consistent with excessive autonomic activation, and polypeptide N-acetyl-galactose-aminyl-transferase 13 (GALNT13), a known pulmonary hypertension (PH) biomarker (−2.7-fold). The most up-regulated gene encodes Periostin (POSTN; 4.5-fold), a matricellular protein relevant to fibrosis. Other dysregulated genes relevant to fibrosis include latent-transforming growth factor beta-binding protein 2 (LTBP2), thrombospondin4 (THBS4). We also identified one dysregulated gene relevant to all disordered transcriptomic pathways, ANNEXIN A1. This anti-inflammatory, phospholipid-binding mediator, is a putative target for therapy in RVF-PAH. Comparison of expression profiles in the MCT-RV with published microarray data from the RV of pulmonary artery-banded mice and humans with bone morphogenetic protein receptor type 2 (BMPR2)-mutations PAH reveals substantial conservation of gene dysregulation, which may facilitate clinical translation of preclinical therapeutic and biomarkers studies. Transcriptomics reveals the molecular fingerprint of RVF to be heavily characterized by mitochondrial dysfunction, fibrosis and inflammation.

Smooth muscle cell-specific FoxM1 controls hypoxia-induced pulmonary hypertension

RATIONALE

Forkhead box M1 (FoxM1) is a transcription factor that promotes cell proliferation by regulating a broad spectrum of genes that participate in cell cycle regulation, such as Cyclin B, CDC25B, and Aurora B Kinase. We have shown that hypoxia, a well-known stimulus for pulmonary hypertension (PH), induces FoxM1 in pulmonary artery smooth muscle cells (PASMC) in a HIF-dependent pathway, resulting in PASMC proliferation, while the suppression of FoxM1 prevents hypoxia-induced PASMC proliferation. However, the implications of FoxM1 in the development of PH remain less known.

METHODS

We determined FoxM1 levels in the lung samples of idiopathic PAH (pulmonary arterial hypertension) (IPAH) patients and hypoxia-induced PH mice. We generated constitutive and inducible smooth muscle cell (SMC)-specific FoxM1 knockdown or knockout mice as well as FoxM1 transgenic mice which overexpress FoxM1, and exposed them to hypoxia (10% O₂, 90% N₂) or normoxia (Room air, 21% oxygen) for four weeks, and measured PH indices. We also isolated mouse PASMC (mPASMC) and mouse embryonic fibroblasts (MEF) from these mice to examine the cell proliferation and expression levels of SMC contractile proteins.

RESULTS

We showed that in hypertensive human lungs or mouse lungs, FoxM1 levels were elevated. Constitutive knockout of FoxM1 in mouse SMC caused early lethality, whereas constitutive knockdown of FoxM1 in mouse SMC prevented hypoxia-induced PH and PASMC proliferation. Inducible knockout of FoxM1 in SMC reversed hypoxia-induced pulmonary artery wall remodeling in existing PH. Overexpression of FoxM1 enhanced hypoxia-induced pulmonary artery wall remodeling and right ventricular hypertrophy in mice. Alteration of FoxM1 status did not affect hypoxia-induced hypoxia-inducible factor (HIF) activity in mice. Knockout of FoxM1 decreased PASMC proliferation and induced expression of SMC contractile proteins and TGF-β/Smad3 signaling.

CONCLUSIONS

Our studies provide clear evidence that altered FoxM1 expression in PASMC contributes to PH and uncover a correlation between Smad3-dependent signaling in FoxM1-mediated proliferation and de-differentiation of PASMC.