Protective effect of nicotinamide and L-arginine against monocrotaline-induced pulmonary hypertension in rats: gender dependence

Background

The purpose of this paper was to examine the effects of nicotinamide (ND) and l-arginine (l-ARG) on pulmonary vascular and heart changes induced by pulmonary hypertension in rats in a gender-dependent way.

Methods

Experiments were performed on male (M) and female (F) rats. PAH was induced via monocrotaline injection (sc, 60/kg B.W.) on day one of the 23-day observational period. After that, the animals were sacrificed, hearts removed and weighed and the papillary muscles isolated to measure force of contraction (F_c). Morphological changes of pulmonary vessels were also examined.

Results

Mixed diet supplementation with l-ARG + ND prevented highly significant right ventricle enlargement induced by PAH in both, male and female rats. Weight ratios between the right ventricle (RV) on one side and the left ventricle with septum on the other (LV + S) decreased from 0.46 ± 0.016 g to 0.29 ± 0.006 g in males and from 0.63 ± 0.03 g to 0.24 ± 0.008 g in females, n = 6, p < 0.001. Additionally, PAH increased basal contractility in female groups, and each of the diet allocations (l-ARG, ND, and mixed) were found to restore contractility to control values. All diet protocols in male and female restored decreased responsiveness of the myocardium to norepinephrine in hearts obtained from rats with PAH and prevented vascular changes observed in pulmonary hypertension (thickness of blood vessels and cell infiltration).

Conclusion

Our study suggests that l-arginine, nicotinamide or both play a positive role in right ventricle function or the process reducing pulmonary vascular remodeling especially in a gender-independent way.

Portopulmonary hypertension in the current era of pulmonary hypertension management

BACKGROUND & AIMS

Long-term outcomes in portopulmonary hypertension (PoPH) are poorly studied in the current era of pulmonary hypertension management. We analysed the effect of pulmonary arterial hypertension (PAH)-targeted therapies, survival and predictors of death in a large contemporary cohort of patients with PoPH.

METHODS

Data from patients with PoPH consecutively enrolled in the French Pulmonary Hypertension Registry between 2007 and 2017 were collected. The effect of initial treatment strategies on functional class, exercise capacity and cardiopulmonary haemodynamics were analysed. Survival and its association with PAH- and hepatic-related characteristics were also examined.

RESULTS

Six hundred and thirty-seven patients (mean age 55 ± 10 years; 58% male) were included. Fifty-seven percent had mild cirrhosis, i.e. Child-Pugh stage A. The median model for end-stage liver disease (MELD) score was 11 (IQR 9-15). Most patients (n = 474; 74%) were initiated on monotherapy, either with a phosphodiesterase-5 inhibitor (n = 336) or with an endothelin-receptor antagonist (n = 128); 95 (15%) were initiated on double oral combination therapy and 5 (1%) on triple therapy. After a median treatment time of 4.5 months, there were significant improvements in functional class (p <0.001), 6-minute walk distance (6MWD) (p <0.0001) and pulmonary vascular resistance (p <0.0001). Overall survival rates were 84%, 69% and 51% at 1, 3 and 5 years, respectively. Baseline 6MWD, sex, age and MELD score or Child-Pugh stage were identified as independent prognostic factors. Survival from PoPH diagnosis was significantly better in the subgroup of patients who underwent liver transplantation (92%, 83% and 81% at 1, 3 and 5 years, respectively).

CONCLUSION

Survival of patients with PoPH is strongly associated with the severity of liver disease. Patients who underwent liver transplantation had the best long-term outcomes.

LAY SUMMARY

Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension in the context of chronic liver disease and is characterized by progressive shortness of breath and exercise limitation. The presence of severe pulmonary arterial hypertension in liver transplant candidates represents a contraindication for such a surgery; however, treatments targeting pulmonary arterial hypertension are efficacious, allowing for safe transplantation and conferring good survival outcomes in those who undergo liver transplantation.

Specific O-GlcNAc modification at Ser-615 modulates eNOS function

Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and devastating disease characterized by vascular smooth muscle and endothelial cell proliferation leading to a narrowing of the vessels in the lung. The increased resistance in the lung and the higher pressures generated result in right heart failure. Nitric Oxide (NO) deficiency is considered a hallmark of IPAH and altered function of endothelial nitric oxide synthase (eNOS), decreases NO production. We recently demonstrated that glucose dysregulation results in augmented protein serine/threonine hydroxyl-linked N-Acetyl-glucosamine (O-GlcNAc) modification in IPAH. In diabetes, dysregulated glucose metabolism has been shown to regulate eNOS function through inhibition of Ser-1177 phosphorylation. However, the link between O-GlcNAc and eNOS function remains unknown. Here we show that increased protein O-GlcNAc occurs on eNOS in PAH and Ser-615 appears to be a novel site of O-GlcNAc modification resulting in reduced eNOS dimerization. Functional characterization of Ser-615 demonstrated the importance of this residue on the regulation of eNOS activity through control of Ser-1177 phosphorylation. Here we demonstrate a previously unidentified regulatory mechanism of eNOS whereby the O-GlcNAc modification of Ser-615 results in reduced eNOS activity and endothelial dysfunction under conditions of glucose dysregulation.

3-Bromopyruvate ameliorates pulmonary arterial hypertension by improving mitochondrial metabolism

AIMS

Abnormal mitochondrial metabolism is an essential factor for excessive proliferation of pulmonary artery smooth muscle cells (PASMCs), which drives the pathological process of pulmonary arterial hypertension (PAH). 3-Bromopyruvate (3-BrPA) is an effective glycolytic inhibitor that improves mitochondrial metabolism, thereby repressing anomalous cell proliferation.

MAIN METHODS

An experimental PAH model was established by injection of monocrotaline (MCT) in male Sprague Dawley rats, following which rats were assigned to three groups: control, MCT, and 3-BrPA groups. Three days post injection of MCT, rats were treated with 3-BrPA or vehicle for 4 weeks. At the end of the study, hemodynamic data were measured to confirm PAH condition. Indicators of pulmonary arterial and right ventricular (RV) remodeling as well as the proliferative ability of PASMCs were assayed. Additionally, mitochondrial morphology and function, and antiglycolytic and antiproliferative pathways and genes were analyzed.

KEY FINDINGS

Treatment with 3-BrPA effectively improved pulmonary vascular remodeling and right ventricular function, inhibited PASMC proliferation, and preserved mitochondrial morphology and function. Besides, 3-BrPA treatment inhibited the PI3K/AKT/mTOR pathway and regulated the expression of antiproliferative genes in PASMCs. However, bloody ascites, bloating, and cirrhosis of organs were observed in some 3-BrPA treated rats.

SIGNIFICANCE

3-BrPA acts as an important glycolytic inhibitor to improve energy metabolism and reverse the course of PAH. However, 3-BrPA is associated with side effects in MCT-induced rats, indicating that it should be caution in drug delivery dosage, and further studies are needed to evaluate this toxicological mechanism.

Integrative analyses of gene expression profile reveal potential crucial roles of mitotic cell cycle and microtubule cytoskeleton in pulmonary artery hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life-threatening condition. The aim of this study was to explore potential crucial genes and pathways associated with PAH based on integrative analyses of gene expression and to shed light on the identification of biomarker for PAH.

METHODS

Gene expression profile of pulmonary tissues from 27 PAH patients and 22 normal controls were downloaded from public database (GSE53408 and GSE113439). After the identification of differentially expressed genes (DEGs), hub pathways and genes were identified based on the comprehensive evaluation of protein-protein interaction (PPI) network analysis, modular analysis and cytohubba's analysis, and further validated in another PAH transcriptomic dataset (GSE33463). Potentially associated micro-RNAs (miRNAs) were also predicted.

RESULTS

A total of 521 DEGs were found between PAH and normal controls, including 432 up-regulated DEGs and 89 down-regulated DEGs. Functional enrichment analysis showed that these DEGs were mainly enriched in mitotic cell cycle process, mitotic cell cycle and microtubule cytoskeleton organization. Moreover, five key genes (CDK1, SMC2, SMC4, KIF23, and CENPE) were identified and then further validated in another transcriptomic dataset associated with special phenotypes of PAH. Furthermore, these hub genes were mainly enriched in promoting mitotic cell cycle process, which may be closely associated with the pathogenesis of PAH. We also found that the predicted miRNAs targeting these hub genes were found to be enriched in TGF-β and Hippo signaling pathway.

CONCLUSION

These findings are expected to gain a further insight into the development of PAH and provide a promising index for the detection of PAH.

Diagnosis of Pulmonary Arterial Hypertension in Children by Using Cardiac Computed Tomography

OBJECTIVE

To establish diagnostic criteria for pulmonary arterial hypertension (PAH) in children by using parameters obtained through noninvasive cardiac computed tomography (CCT).

MATERIALS AND METHODS

We retrospectively measured parameters from CCT images of children from a single institution in a multiple stepwise process. A total of 208 children with mean age of 10.5 years (range: 4 days-18.9 years) were assessed. The variables were classified into three groups: the great arteries; the ventricular walls; and the bilateral ventricular cavities. The relationship between the parameters obtained from the CCT images and mean pulmonary arterial pressure (mPAP) was tested and adjusted by the children's body size. Reference curves for the pulmonary trunk diameter (PTD) and ratio of diameter of pulmonary trunk to ascending aorta (rPTAo) of children with CCT images of normal hearts, adjusted for height, were plotted. Threshold lines were established on the reference curves.

RESULTS

PTD and rPTAo on the CCT images were significantly positively correlated with mPAP (r > 0.85, p < 0.01). Height was the body size parameter most correlated with PTD (r = 0.91, p < 0.01) and rPTAo (r = -0.69, p < 0.01). On the basis of the threshold lines on the reference curves, PTD and rPTAo both showed 88.9% sensitivity for PAH diagnosis, with negative predictive values of 93.3% and 92.9%, respectively.

CONCLUSION

PTD and rPTAo measured from CCT images were significantly correlated with mPAP in children. Reference curves and the formula of PTD and rPTAo adjusted for height could be practical for diagnosing PAH in children.

MiR-18a-5p contributes to enhanced proliferation and migration of PASMCs via targeting Notch2 in pulmonary arterial hypertension

AIM

This study is undertaken to investigate the role and molecular mechanisms of miR-18a-5p in regulating pulmonary arterial hypertension (PAH) pathogenesis.

METHODS

Gene expression and protein levels were determined by qRT-PCR and western blot, respectively; Cell counting kti-8 and Transwell migration assays were used to determine the biological functions of miR-18a-5p in pulmonary arterial smooth muscle cells (PASMCs); bioinformatics analysis, luciferase reporter assays were used to elucidate the mechanisms of miR-18a-5p.

RESULTS

MiR-18a-5p was up-regulated in the clinical samples from PAH patients. PASMCs treated with hypoxia exhibited enhanced proliferative ability and upregulated miR-18a-5p expression. Knockdown of miR-18a-5p attenuated hypoxia-induced hyper-proliferation and enhanced migratory potential of PASMCs; while miR-18a-5p overexpression promoted PASMC proliferation and migration. Further mechanistic studies showed that Notch2 was a direct target of miR-18a-5p and was repressed by miR-18a-5p overexpression. The rescue studies indicated that Notch2 overexpression counteracted the enhanced proliferation and migration induced by miR-18a-5p mimics in PASMCs. Similarly, Notch2 overexpression also block the effects caused by hypoxia in PASMCs. Moreover, Notch2 expression was down-regulated in the PAH patients and was negatively correlated with miR-18a-5p expression. In vivo animal studies further revealed the up-regulation of miR-18a-5p and the down-regulation of Notch2 in the PAH rats.

CONCLUSIONS

Collectively, this study identified the up-regulated miR-18a-5p in the PAH patients; our data suggest that miR-18a-5p contributes to the enhanced proliferation and migration of PASMCs via repressing Notch2 expression.

Recommendations for the care of patients with heart failure and COVID-19

The COVID-19 pandemic decreed by the World Health Organization (WHO) since March 12, 2020 is wreaking havoc globally and it is a true economic, social and health challenge. Although the clinical manifestations of COVID-19 are respiratory symptoms, some patients also have cardiological symptoms. Among patients with cardiological conditions2 they represent a group of higher risk and, in fact, they are a particularly vulnerable group, due to their higher risk of contagion and greater severity in case of acquiring the disease1 those with heart failure (HF), including heart transplant (CT) and ventricular assists, as well as patients with pulmonary arterial hypertension (PAH). HF is the main chronic cardiovascular disease and patients in this group are the most vulnerable for the development of more serious clinical symptoms after suffering the infection, and to a greater extent cases with advanced HF3. In fact, HF is one of the most frequent complications in patients with COVID-194. Likewise, transplant patients who require immunosuppressants to avoid graft rejection, constitute a population especially susceptible to infection and to develop more serious processes. This situation has made the National Association of Cardiologists of Mexico (ANCAM) and the Mexican Society of Cardiology (SMC) together with their respective chapters, have prepared the following recommendations for medical personnel, who participate in the care of this special group of patients in the different clinical settings, who suffer or not, of COVID-19.

Atrial Septal Defect

Atrial septal defects are common congenital heart defects, characterized by insufficient/absent tissue at the interatrial septum. An unrepaired defect may be associated with right heart volume overload, atrial arrhythmia or pulmonary arterial hypertension. The 3 major types of atrial septal defect are: ostium secundum defect, ostium primum defect, and sinus venosus. Characteristic physical findings include a midsystolic pulmonary flow or ejection murmur, accompanied by a fixed split-second heart sound. Small defects may spontaneously close; larger defects may persist and result in hemodynamic and clinical sequelae requiring percutaneous or surgical intervention. Severe pulmonary arterial hypertension is a contraindication to closure.

Interleukin-32 in systemic sclerosis, a potential new biomarker for pulmonary arterial hypertension

Background

Pulmonary arterial hypertension (PAH) is a severe complication of systemic sclerosis (SSc), associated with a progressive elevation in pulmonary vascular resistance and subsequent right heart failure and death. Due to unspecific symptoms, the diagnosis of PAH is often delayed. On this basis, it is of great value to improve current diagnostic methods and develop new strategies for evaluating patients with suspected PAH. Interleukin-32 (IL-32) is a proinflammatory cytokine expressed in damaged vascular cells, and the present study aimed to assess if this cytokine could be a new biomarker of PAH during SSc.

Methods

The IL-32 expression was evaluated in the sera and skin samples of 18 SSc-PAH patients, 21 SSc patients without PAH, 15 patients with idiopathic PAH (iPAH) and 14 healthy controls (HCs), by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC). Receiver-operating characteristic (ROC) curves were performed to evaluate the cut-off of IL-32 in identifying patients with PAH. Furthermore, in SSc patients, correlation analyses were performed between IL-32 sera levels and mean pulmonary artery pressure (mPAP) evaluated by right heart catheterization (RHC) and systolic pulmonary artery pressure (sPAP), obtained by echocardiography. Additionally, the number of skin IL-32+ cells was correlated with modified Rodnan skin score (mRSS).

Results

In SSc-PAH patients, IL-32 sera levels were significantly higher when compared with SSc patients without PAH and patients affected by iPAH. The analysis of ROC curve showed that IL-32 sera levels above 11.12 pg/ml were able to predict patients with PAH (sensitivity = 90%, specificity = 100%). Furthermore, the IL-32 sera levels of patients with SSc correlated with both mPAP and sPAP. In the skin derived from SSc-PAH patients, the number of IL-32+ cells was significantly increased when compared with the skin derived from SSc patients without PAH, correlating with the mRSS.

Conclusion

Our study suggested that sera determination of IL-32 may be a promising approach to evaluate the presence of PAH in SSc patients and together with longitudinal future studies could help to increase the understanding how these biomarkers mirror the vascular changes and the inflammatory process during SSc.

Long-term treatment of pulmonary arterial hypertension with macitentan in Japanese patients

Objective: Macitentan, a novel dual endothelin receptor antagonist, was approved for the treatment of pulmonary arterial hypertension (PAH) in Japan. However, long-term effects in Japanese patients of macitentan are currently unavailable. This study sought to assess the long-term efficacy and safety of macitentan in Japanese patients with PAH.Methods: In this multicenter, open-label, clinical extension study (JapicCTI-121986), efficacy was evaluated based on the change from baseline at 24, 48, 72, 96 and 120-week in the 6-minute walk distance (6MWD), World Health Organization (WHO) functional class, and serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels. In addition, the time to a hospitalization related to PAH and a morbidity/mortality event was determined. As for safety, the incidence of adverse events and changes in laboratory data and vital signs were assessed.Results: Macitentan was administered at a once-daily dose of 10 mg in 30 PAH patients with a median treatment period of 2.4 years (range, 229-1037 days). The improvements in 6MWD, WHO functional class and NT-pro-BNP at week 24 were maintained throughout the long-term follow-up. Hospitalization related to PAH occurred in 2 patients. Levels of liver enzyme and hemoglobin remained unchanged throughout the study period.Conclusions: This study suggests that the long-term use of macitentan is well tolerated and effective in Japanese patients with PAH. We concluded that macitentan can be a possible approach to reduce morbidity/mortality in Japanese PAH patients.

Highly expressed BMP9/GDF2 in postnatal mouse liver and lungs may account for its pleiotropic effects on stem cell differentiation, angiogenesis, tumor growth and metabolism

Bone morphogenetic protein 9 (BMP9) (or GDF2) was originally identified from fetal mouse liver cDNA libraries. Emerging evidence indicates BMP9 exerts diverse and pleiotropic functions during postnatal development and in maintaining tissue homeostasis. However, the expression landscape of BMP9 signaling during development and/or in adult tissues remains to be analyzed. Here, we conducted a comprehensive analysis of the expression landscape of BMP9 and its signaling mediators in postnatal mice. By analyzing mouse ENCODE transcriptome datasets we found Bmp9 was highly expressed in the liver and detectable in embryonic brain, adult lungs and adult placenta. We next conducted a comprehensive qPCR analysis of RNAs isolated from major mouse tissues/organs at various ages. We found that Bmp9 was highly expressed in the liver and lung tissues of young adult mice, but decreased in older mice. Interestingly, Bmp9 was only expressed at low to modest levels in developing bones. BMP9-associated TGFβ/BMPR type I receptor Alk1 was highly expressed in the adult lungs. Furthermore, the feedback inhibitor Smads Smad6 and Smad7 were widely expressed in mouse postnatal tissues. However, the BMP signaling antagonist noggin was highly expressed in fat and heart in the older age groups, as well as in kidney, liver and lungs in a biphasic fashion. Thus, our findings indicate that the circulating BMP9 produced in liver and lungs may account for its pleiotropic effects on postnatal tissues/organs although possible roles of BMP9 signaling in liver and lungs remain to be fully understood.

Three-dimensional biventricular strains in pulmonary arterial hypertension patients using hyperelastic warping

BACKGROUND AND OBJECTIVE

Evaluation of biventricular function is an essential component of clinical management in pulmonary arterial hypertension (PAH). This study aims to examine the utility of biventricular strains derived from a model-to-image registration technique in PAH patients in comparison to age- and gender-matched normal controls.

METHODS

A three-dimensional (3D) model was reconstructed from cine short- and long-axis cardiac magnetic resonance (CMR) images and subsequently partitioned into right ventricle (RV), left ventricle (LV) and septum. The hyperelastic warping method was used to register the meshed biventricular finite element model throughout the cardiac cycle and obtain the corresponding biventricular circumferential, longitudinal and radial strains.

RESULTS

Intra- and inter-observer reproducibility of biventricular strains was excellent with all intra-class correlation coefficients > 0.84. 3D biventricular longitudinal, circumferential and radial strains for RV, LV and septum were significantly decreased in PAH patients compared with controls. Receiver operating characteristic (ROC) analysis showed that the 3D biventricular strains were better early markers (Area under the ROC curve = 0.96 for RV longitudinal strain) of ventricular dysfunction than conventional parameters such as two-dimensional strains and ejection fraction.

CONCLUSIONS

Our highly reproducible methodology holds potential for extending CMR imaging to characterize 3D biventricular strains, eventually leading to deeper understanding of biventricular mechanics in PAH.

A novel rat model of pulmonary hypertension induced by mono treatment with SU5416

Pulmonary hypertension (PH) is responsible for premature death caused by progressive and severe heart failure. A simple, feasible, and reproducible animal model of PH is essential for the investigation of the pathogenesis and treatment of this condition. Previous studies have demonstrated that the vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitor SU5416 combined with hypoxia could establish an animal model of PH. Here, we investigated whether SU5416 itself could induce PH in rats. The effects of SU5416 treatment followed by 5 weeks of normoxia were examined. Hemodynamic measurements and histological assessments of the pulmonary vasculature and the heart were conducted to evaluate the physiological and pathophysiological characteristics of PH. Compared with the control rats, the SU5416-treated rats showed significantly increased right ventricle systolic pressure, right ventricle mass, total pulmonary vascular resistance, and total pulmonary vascular resistance index, while the cardiac output and cardiac index were substantially decreased. Moreover, the degree of occlusion and the muscularization levels of the distal small pulmonary vessels and the medial wall thickness of larger vessels (OD > 50 μm) simultaneously increased. SU5416 inhibited pulmonary vascular endothelial cell apoptosis in rats, as shown by immunostaining of cleaved caspase-3. Furthermore, changes in the right ventricle, myocardial hypertrophy, myocardial edema, myocardial necrosis, striated muscle cell atrophy, vessel muscularization, neointimal occlusion, and increased collagen deposition were observed in the SU5416 group compared with the control group. Thus, treatment with SU5416 alone plus 5 weeks of normoxia could be sufficient to induce PH in rats, which may provide a good and convenient model for future investigation of PH.

Effects of upper extremity aerobic exercise training on oxygen consumption, exercise capacity, dyspnea and quality of life in patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary and extrapulmonary impairments are prevalent in pulmonary arterial hypertension (PAH) which is a rare, chronic and progressive disease.

OBJECTIVES

To investigate the effects of upper extremity aerobic exercise training on exercise capacity, oxygen consumption, dyspnea and quality of life in patients with PAH.

METHODS

In a prospective, randomized controlled, double-blinded study, eleven patients in training group applied upper extremity aerobic exercise training (50-80% of maximal heart rate), 15-45 min/day, 3 days a week for 6 weeks and 11 patients in control group alternating active upper extremity exercises for the same period. Exercise capacity evaluated using six minute walk test (6MWT), oxygen consumption simultaneously measured during 6MWT using a portable instrument, dyspnea modified Borg scale and Modified Medical Research Council dyspnea scale and quality of life Short Form 36 Health Survey, before and after the exercise training.

RESULTS

Baseline characteristics of groups were similar (p>0.05). Dyspnea (p<0.001) and peak oxygen consumption (p = 0.031) were significantly improved in training group compared the controls. Dyspnea, exercise capacity, peak oxygen consumption, minute ventilation, tidal volume, end tidal carbon-dioxide pressure, and vitality, social functioning and role-physical were significantly improved within training group (p<0.05). Oxygen consumption at anaerobic threshold were significantly decreased within control group (p<0.05).

CONCLUSIONS

Upper extremity aerobic exercise training improves oxygen consumption, and decreases dyspnea perception. It is a safe and effective intervention in patients with PAH. (ClinicalTrials.gov registration: NCT02371733).

Risk stratification and prognostic factors in patients with pulmonary arterial hypertension and comorbidities a cross-sectional cohort study with survival follow-up

BACKGROUND

The objective of this study was to analyze prognostic factors and risk stratification in patients with pulmonary arterial hypertension (PAH) and comorbidities.

METHODS

Patients with invasively diagnosed PAH were included in the analysis. Comorbidities were clinically diagnosed as proposed in the 6th World Symposium of pulmonary hypertension. Uni- and multivariate analysis were employed for identification of factors predicting survival and time to first clinical worsening (TTCW). Risk stratification was based on parameters from ESC/ERS-guidelines 2015.

RESULTS

In total 142 patients were enrolled in the study, 90 of them were diagnosed as PAH without and 52 with comorbidities. All patients received targeted PAH therapy and were followed for 3.3 ± 2.4 years. In PAH patients without comorbidities survival and TTCW were significantly associated with reduced 6-min walking distance (6MWD), elevated N-terminal pro brain natriuretic peptide (NT-proBNP), WHO-functional class (WHO-FC) and right atrial (RA) area. In the multivariate analysis, 6MWD was an independent predictor for survival (p = 0.002) and WHO-FC for TTCW (p = 0.001). In patients with PAH and comorbidities these parameters had no significant association with survival and TTCW. Average risk score was significantly associated with survival (p = 0.001) and TTCW (p = 0.013) in PAH but not in PAH with comorbidities (both p > 0.05; figure 1).

CONCLUSION

Risk stratification based on ESC/ERS-guidelines could only be confirmed in patients without comorbidities, but not in patients with PAH and comorbidities. The data of this study suggest, that a different risk stratification needs to be applied to PAH patients with comorbidities. Further studies are needed to confirm these results.

TRIAL REGISTRATION

Not applicable, retrospective registry.

The therapeutic potential of BRD4 in cardiovascular disease

Bromodomain-containing protein 4 (BRD4) is a member of the bromodomain and extra terminal (BET) protein family that has gained wide attention in the field of cancer due to its role in the formation of super enhancers (SEs) and the regulation of oncogene expression. However, there is increasing evidence that BRD4 also plays a pivotal role in a variety of cardiovascular diseases, suggesting that understanding the mechanisms of BRD4 in these diseases is important to advance studies and clinical treatment. In this article, we summarize the mechanisms of BRD4 in cardiovascular diseases, including pulmonary arterial hypertension, heart failure, atherosclerosis, and hypertension. In addition, we discuss small molecule inhibitors of BRD4 as novel therapeutic strategies for cardiovascular diseases.

Pulmonary artery denervation for pulmonary arterial hypertension

Pulmonary arterial hypertension remains a progressive, life-limiting disease despite optimal medical therapy. Pulmonary artery denervation has arisen as a novel intervention in the treatment of pulmonary arterial hypertension, and other forms of pulmonary hypertension, with the aim of reducing the sympathetic activity of the pulmonary circulation. Pre-clinical studies and initial clinical trials have demonstrated that the technique can be performed safely with some positive effects on clinical, haemodynamic and echocardiographic markers of disease. The scope of the technique in current practice remains limited given the absence of well-designed, large-scale, international randomised controlled clinical trials. This review provides an overview of this exciting new treatment modality, including pathophysiology, technical innovations and recent trial results.

Risk assessment in PAH using quantitative CMR tricuspid regurgitation: relation to heart catheterization

Aims

Improved risk stratification is of value for decision making in pulmonary arterial hypertension (PAH). Right heart catheterization combined with quantitative tricuspid regurgitation (TR) by cardiovascular magnetic resonance (CMR) may provide this. The aims were to study: (i) to what extent quantitative TR is associated with event‐free survival; (ii) how quantitative TR is related to known prognostic markers in PAH; and (iii) to what extent quantitative TR and right atrial pressure determine right atrial dilation.

Methods and results

Fifty patients (63 ± 17 years) with PAH referred for CMR were included. Volumes and pulmonary artery flow by CMR and pressure and vascular resistance by right heart catheterization were obtained. Composite outcome was lung transplantation or death. Four transplantations and 27 deaths occurred over a median of 2.7 years. A trend towards higher hazard ratio was shown for TR volume (TRV; 2.1, 95% CI 1.0–4.4) and TR fraction (TR%; 1.6, 95% CI 0.8–3.3) above median. TRV and TR% correlated with right ventricular (RV) end‐diastolic (TRV r = 0.50; TR% r = 0.39) and end‐systolic (TRV r = 0.35; TR% r = 0.30) volumes, pulmonary vascular resistance (TRV r = 0.28; TR% r = 0.43), N terminal pro brain natriuretic peptide (TRV r = 0.65; TR% r = 0.68), cardiac index (TRV r = −0.32; TR% r = −0.54), pulmonary artery stroke volume (TRV r = −0.32; TR% r = −0.58) and effective RV ejection fraction by pulmonary artery quantitative flow (TRV r = −0.56; TR% r = −0.69), but not RVEF. Both TR% and right atrial pressure determined right atrial volumes (r² = 0.38; r² = 0.48).

Conclusions

A clear trend towards worse outcome with larger TRV or TR% was shown; however, the number of events was insufficient for significant outcome differences. Prognostic value of quantitative TR should be investigated in a larger multicentre cohort. Effective RV ejection fraction may be considered an improved measure of RV function in PAH.

Transition protocol from subcutaneous treprostinil to intravenous epoprostenol in deteriorating patients with pulmonary arterial hypertension

BACKGROUND

Despite advantages in the treatment options of pulmonary arterial hypertension, continuous parenteral prostanoid administration, although often complicated by serious side effects, remains the treatment of choice for patients with advanced disease. The need of transitioning from one parenteral prostanoid agent to the other is often faced in the daily clinical practise. Up to today, there is no established transition protocol from subcutaneous treprostinil to intravenous epoprostenol.

METHODS

A staggered approach to subcutaneous treprostinil down-titration with simultaneous epoprostenol up-titration is described. Subcutaneous treprostinil is down-titrated by 5 ng/kg/min every 5 h while intravenous epoprostenol is up-titrated by 2 ng/kg/min every 2 h.

RESULTS

The designed protocol was implemented in 4 patients with pulmonary arterial hypertension (3 women, median age 70.5 (range 38-79) years). Median starting subcutaneous treprostinil dose was 44.5 (range 37-100) ng/kg/min and median treprostinil down-titration time was 32.5 (range 25-85) hours. The median maximal epoprostenol dose was 36 (range 28-90) ng/kg/min, achieved in 36 (range 30-90) hours. Only mild prostanoid-related side effects were reported.

CONCLUSIONS

The proposed staggered transition protocol from subcutaneous treprostinil to intravenous epoprostenol was safe in a limited number of patients with pulmonary arterial hypertension.

Pulmonary Arterial Hypertension in a Patient with a Portosystemic Shunt: Diagnostic Challenge

•

Pediatric pulmonary arterial hypertension (PAH) is a rare condition.

•

The diagnostic algorithm in PAH is key to address rare pathology and make a diagnosis.

•

Portosystemic shunt is a rare anomaly of the mesenteric vasculature.

•

PAH is diagnosed by echocardiography and portocaval shunt is diagnosed using image.

•

Infrequent case of reversible PAH after surgical repair of Abernethy malformation.

Reduction of the serotonin 5-HT1B and 5-HT2A receptor-mediated contraction of human pulmonary artery by the combined 5-HT1B receptor antagonist and serotonin transporter inhibitor LY393558

Background

LY393558 is a combined antagonist of serotonin (5-HT) 5-HT_1B receptors and inhibitor of serotonin transporter (SERT). LY393558 reduces 5-HT-induced vasoconstriction and remodelling of rat and/or mouse pulmonary arteries. The aim of our study was to examine the effect of LY393558 on the 5-HT-stimulated vasoconstriction of human pulmonary arteries (hPAs) and to determine the underlying mechanism(s).

Methods

Vascular effects of 5-HT receptor agonists, antagonists and a SERT inhibitor were examined in organ bath studies on intralobar hPAs obtained from patients during resection of lung carcinoma.

Results

Serotonin and agonists of the 5-HT_1B receptor (5-carboxamidotryptamine, 5-CT) and 5-HT_2A receptor (α-methyl-5-HT) contracted endothelium-intact hPAs in a concentration-dependent fashion. The 5-HT_1B antagonists SB224289 and GR55562 reduced responses induced by 5-HT and 5-CT and the 5-HT_2A antagonist ketanserin inhibited the effects of 5-HT and α-methyl-5-HT. Administration of the SERT inhibitor citalopram (at a concentration that failed to modify the 5-HT-induced vasoconstriction) in combination with SB224289 or GR55562 was more effective in inhibiting the response to 5-HT than the 5-HT_1B antagonists alone. LY393558 showed the greatest antagonistic effect against the vasoconstriction elicited by 5-HT, 5-CT and α-methyl-5-HT.

Conclusions

LY393558 reduces the 5-HT-induced contraction antagonizing 5-HT_1B and 5-HT_2A receptors probably due to synergic interaction between SERT inhibition and 5-HT_1B receptor antagonism. Thus, it might represent a valuable future option in the pulmonary arterial hypertension therapy.

Image diagnosis: Eisenmenger's syndrome in patients with simple congenital heart disease

BACKGROUND

Early identification of congenital heart disease (CHD) allows detection of the pulmonary arteriopathy in an early stage, and timely shunt closure can permanently reverse pulmonary arterial hypertension (PAH). However, surgical correction is not recommended in patients with irreversible PAH. Herein we report our experience about Eisenmenger's syndrome in simple CHD.

CASE PRESENTATION

From January 2017 to November 2018, a total of 8 CHD patients (3 ventricular septal defects (VSD), 2 atrial septal defects (ASD), and 3 patent ductus arteriosus (PDA), median age, 15.5 years [range, 3-18 years]) with PAH were detected by chest X-ray, electrocardiogram, transthoracic echocardiography (TTE), computed tomographic angiography (CTA) and cardiac catheterization. The median defect diameter, pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR) were 16.5 mm (range, 3-30 mm), 75 mmHg (range, 60-86 mmHg), and 16 Woods units (range, 12-19 Woods units), respectively. Here, we report the representative cases of three types of simple CHD with irreversible PAH. The surgical correction was not performed in all patients who had fixed PAH and were referred to medical treatment.

CONCLUSIONS

PAH in CHD can be reversed by early shunt closure, but this potential is lost beyond a certain point of no return. This article highlights the essence of enhancing the level of healthcare and services in Chinese rural areas. Failure to accurately and timely assess PAH will delay effective treatment past optimal treatment time, and even lead to death.

Short-term results of interventional therapy for infants (7-36 months old) with patent ductus arteriosus and moderate-to-severe pulmonary hypertension: a retrospective study

BACKGROUND

Patent ductus arteriosus (PDA) is a common congenital heart disease. Interventional therapy is an important treatment for PDA. Nevertheless, few studies have investigated the safety and effectiveness of interventional therapy for infants (age, 0-36 months) with PDA and moderate-to-severe pulmonary hypertension. Therefore, this study aimed to analyze the short-term (6 months) results and interventional therapy experience for infants with PDA and moderate-to-severe pulmonary hypertension.

METHODS

Clinical records, echocardiographic data, and angiocardiography data of 28 infants (age, 7-36 months) who underwent interventional therapy for PDA and moderate-to-severe pulmonary hypertension between December 2011 and January 2017 at our hospital were retrospectively analyzed. All infants were treated using an Amplatzer occluder with local and deep sedation anesthesia under radiographic guidance.

RESULTS

Infants with PDA and moderate-to-severe pulmonary hypertension had poor growth. Trace residual shunts were found in two infants immediately after procedure; both had disappeared by 6 months after procedure. No significant interventional therapy-related complications occurred in the other cases. Pulmonary systolic pressure, left atrial dimension, and left ventricular end-diastolic dimension immediately after interventional therapy and 6 months later were lower than the preoperative levels (P < 0.05). The left atrial and left ventricular end-diastolic dimensions at 6 months after interventional therapy were smaller than those immediately after interventional therapy (P < 0.05). Pulmonary systolic pressure rates immediately after interventional therapy and 6 months later were not significantly different (P = 0.505). Moreover, there were no significant differences in the left ventricular ejection fraction before, immediately after, and at 6 months after interventional therapy (P = 0.628).

CONCLUSIONS

For infants (age, 7-36 months) with PDA and moderate-to-severe pulmonary hypertension, interventional therapy can achieve excellent immediate and short-term (6 months) results with careful preoperative evaluations, strict operative procedures, and careful follow-up.

Assessment of lung glucose uptake in patients with systemic lupus erythematosus pulmonary arterial hypertension: a quantitative FDG-PET imaging study

PURPOSE

Pulmonary arterial hypertension (PAH) is a recognized complication of systemic lupus erythematosus (SLE-PAH) patients and its lung pathology shares similarity to idiopathic PAH (IPAH) with distinctive inflammatory feature. FDG-PET reports glucose metabolism from both hyperproliferative and inflammatory cellular elements of vascular pathology in PAH. We explored the application of FDG-PET in reporting SLE-PAH pulmonary vascular pathology.

METHODS

Sixty-minute dynamic FDG-PET imaging was applied in 14 SLE-PAH patients, 20 IPAH patients and 10 healthy volunteers. Patlak analysis was used to quantify lung FDG uptake (influx rate Ki).

RESULTS

Mean lung FDG uptake in SLE-PAH (Ki 0.00714 ± 0.000602 mL/g/min) was significantly higher than that of the healthy volunteers (Ki 0.000262 ± 0.000168 mL/g/min) (p < 0.05). SLE-PAH patients with SLE disease activity score SLEDAI ≥ 5 demonstrated significantly increased lung FDG uptake (Ki 0.001075 ± 0.00055 mL/g/min) than those with SLEDAI < 5 (Ki 0.000233 ± 0.00017 mL/g/min) (p = 0.0038) and IPAH (Ki 0.000524 ± 0.000314 mL/g/min) (p = 0.0025). Lung FDG uptake in SLE-PAH correlated with SLEDAI score and plasma complement C3 and C4 levels (Ki vs SLEDAI, r = 0.607, p = 0.021; Ki vs C3, r = - 0.568, p = 0.034; Ki vs C4, r = - 0.661, p = 0.010). There were no significantly correlations between lung FDG uptake and pulmonary vascular haemodynamics and 6 min walking distance in both IPAH and SLE-PAH patients.

CONCLUSIONS

Our data indicated that increased lung FDG uptake in SLE-PAH patients correlates with SLE disease activity (SLEDAI) and immune/inflammatory status (C3 and C4). FDG-PET imaging may be developed as a potential intrapulmonary disease activity marker in SLE-PAH patients.