Treatment and Clinical Management of Chronic Thromboembolic Pulmonary Hypertension:An Update of Literature Review

Chronic thromboembolic pulmonary hypertension(CTEPH)is a chronic,progressive,debilitating,and life-threa-tening complication of pulmonary embolism(PE).Recent technological advances have permitted various treat-ment options for the treatment of CTEPH,including surgery,angioplasty,and medical treatment,depending on the location and characteristics of lesions.Pulmonary endarterectomy(PEA)is the treatment of choice for CTEPH,as it offers excellent long-term outcomes and a high probability of recovery.Moreover,various medical and interventional therapies are currently being developed for patients with inoperable CTEPH.This review mainly summarizes the current treatment approaches of CTEPH,offering more options for specialist physicians to,thus,better manage chronic thromboembolic syndromes.

Development of pulmonary hypertension remains a major hurdle to corrective surgery in Down syndrome

Down syndrome is the most common chromosomal abnormality encountered in clinical practice with 50%of them having associated congenital heart disease(CHD).Shunt lesions account for around 75%of all CHDs in Down syndrome.Down syndrome patients,especially with large shunts are particularly predisposed to early development of severe pulmonary hypertension(PH)compared with shunt lesions in general population.This necessitates timely surgical correction which remains the only viable option to prevent long term morbidity and mortality.However,despite clear recommendations,there is wide gap between actual practice and fear of underlying PH which often leads to surgical refusals in Down syndrome even when the shunt is reversible.Another peculiarity is that Down syndrome patients can develop PH even after successful correction of shunt.It is not uncommon to come across Down syndrome patients with uncorrected shunts in adulthood with irreversible PH at which stage intracardiac repair is contraindicated and the only option available is a combined heartlung transplant.However,despite the guidelines laid by authorities,the rates of cardiac transplant in adult Down syndrome remain dismal largely attributable to the high prevalence of intellectual disability in them.The index case presents a real-world scenario highlighting the impact of severe PH on treatment strategies and discrimination driven by the fear of worse outcomes in these patients.

Effects of combined aerobic,resistance and inspiratory training in patients with pulmonary hypertension:A systematic review

BACKGROUND Pulmonary hypertension(PH)is a serious progressive disorder of the modern world,characterized by endothelial dysfunction and impaired vasoreactivity.Patients with PH usually present exercise intolerance from the very early stages and reduced exercise capacity.Exercise training has been shown to have beneficial effects in patients with cardiovascular comorbidities.However,data regarding the effects of combined exercise training programs in patients with PH still remains limited.AIM To investigate the effects of combined exercise training programs on exercise capacity and quality of life in patients with PH.METHODS Our search included all available randomized controlled trials(RCTs)regarding combined aerobic,resistance and inspiratory training programs in patients with PH in 4 databases(Pubmed,PEDro,Embase,CINAHL)from 2012 to 2022.Five RCTs were included in the final analysis.Functional capacity,assessed by peak VO_(2)or 6-min walking test(6MWT),as well as quality of life,assessed by the SF-36 questionnaire,were set as the primary outcomes in our study.RESULTS Peak VO_(2)was measured in 4 out of the 5 RCTs while 6MWT was measured in all RCTs.Both indices of functional capacity were significantly increased in patients with PH who underwent combined exercise training compared to the controls in all of the included RCTs(P<0.05).Quality of life was measured in 4 out of 5 RCTs.Although patients improved their quality of life in each group,however,only 2 RCTs demonstrated further improvement in patients performing combined training compared to controls.CONCLUSION By this systematic review,we have demonstrated that combined aerobic,resistance and inspiratory exercise training is safe and has beneficial effects on aerobic capacity and quality of life in patients with PH.Such exercise training regimen may be part of the therapeutic strategy of the syndrome.

Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review

Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope.

Pulmonary hypertension,nephrotic syndrome,and polymyositis due to hepatitis C virus infection:A case report

BACKGROUND Hepatitis C infection not only damages the liver but also often accompanies many extrahepatic manifestations.Incidences of pulmonary hypertension(PH)caused by hepatitis C are rare,and incidences of concurrent nephrotic syndrome and polymyositis are even rarer.CASE SUMMARY Herein we describe the case of a 57-year-old woman who was admitted to our department for intermittent chest tightness upon exertion for 5 years,aggravated with dyspnea for 10 d.After relevant examinations she was diagnosed with PH,nephrotic syndrome,and polymyositis due to chronic hepatitis C infection.A multi-disciplinary recommendation was that the patient should be treated with sildenafil and macitentan in combination and methylprednisolone.During treatment autoimmune symptoms,liver function,hepatitis C RNA levels,and cardiac parameters of right heart catheterization were monitored closely.The patient showed significant improvement in 6-min walking distance from 100 to 300 m at 3-mo follow-up and pulmonary artery pressure drops to 50 mmHg.Long-term follow-up is needed to confirm further efficacy and safety.CONCLUSION Increasing evidence supports a relationship between hepatitis C infection and diverse extrahepatic manifestations,but it is very rare to have PH,nephrotic syndrome,and polymyositis in a single patient.We conducted a literature review on the management of several specific extrahepatic manifestations of hepatitis C.

Pulmonary Hypertension Crisis in Patient with Tetralogy of Fallot and Mixed Total Anomalous Pulmonary Vein Connection after the Primary Correction:A Rare Case Report

Tetralogy of Fallot(TOF)with total anomalous pulmonary vein connections(TAPVC)is a rare type of complex congenital heart disease among all TOF cases.Co-presentation of major aortopulmonary collateral arteries(MAPCAs)compensates for the lack of central pulmonary bloodflow and decreases the severity of right-to-left shunting in TOF.We present a case of a 2-year-old child with complex diagnoses of TOF,TAPVC,a large secun-dum atrial septal defect(ASD),and intraoperatively identified MAPCAs.She underwent surgery to repair the TAPVC,valve-sparing reconstruction of the right ventricular outflow tract,interventricular defect closure,and the creation of patent foramen ovale(PFO).After the operation,hemodynamic instability happened along with sudden blood pressure drop,desaturation,and increased central venous pressure,which subsided after adminis-tering inhalational nitric oxide(NO).A postoperative pulmonary hypertension crisis was suggested when the patient experienced recurrent symptoms after the termination of NO.Echocardiographicfindings of a D-shaped left ventricle(LV),right-to-left PFO shunt and high tricuspid valve gradientfirmly established the diagnosis.It was subsequently managed with continuous NO inhalation and sildenafil,which rendered a satisfactory outcome.Repaired TOF and TAPVC could be at particular risk of developing pulmonary hypertension crisis,especially in the presence of MAPCAs due to possible remodeling of the pulmonary vasculature.Furthermore,a relatively non-compliant LV function and small left atrial size may exacerbate the risk of developing postcapillary pulmonary hypertension after TAPVC repair.A successful postoperative outcome calls for a meticulous preoperative analysis of the anatomical lesions,as well as careful monitoring.

Twin pregnancy with sudden heart failure and pulmonary hypertension after atrial septal defect repair: A case report

BACKGROUND Pulmonary arterial hypertension(PAH)in pregnancy is one of the major obstetric complications and is considered a contraindication to pregnancy as it is classified as a class IV risk in the revised risk classification of pregnancy by the World Health Organisation.Pregnancy,with its adaptive and expectant mechanical and hormonal changes,negatively affects the cardiopulmonary circulation in pregnant women.Do patients with repaired simple congenital heart disease(CHD)develop other pulmonary and cardiac complications during pregnancy?Can pregnant women with sudden pulmonary hypertension be treated and managed in time?In this paper,we present a case of a 39-year-old woman who underwent cesarean section at 33 wk'gestation and developed PAH secondary to repaired simple CHD.Our research began by a PubMed search for"pulmonary hypertension"and"pregnancy"and"CHD"case reports.Three cases were selected to review PAH in pregnancy after correction of CHD defects.These studies were reviewed,coupled with our own clinical experience.CASE SUMMARY Herein,a case involving a woman who underwent atrial septal defect repair at the age of 34,became pregnant five years later,and had a sudden onset of PAH and right heart failure secondary to symptoms of acute peripheral edema in the third trimester of her pregnancy.As a result,the patient underwent a cesarean section and gave birth to healthy twins.Within three days after cesarean delivery,her cardiac function deteriorated as the pulmonary artery pressure increased.Effec-tive postpartum management,including diuresis,significant oxygen uptake,vasodilators,capacity and anticoagulants management,led to improvements in cardiac function and oxygenation.The patient was discharged from hospital with a stable recovery and transferred to local hospitals for further PAH treatment.CONCLUSION This case served as a reminder to obstetricians of the importance of pregnancy after repair of CHD.It is crucial for patients with CHD to receive early correction.It suggests doctors should not ignore edema of twin pregnancy.Also,it provides a reference for the further standardization of antenatal,in-trapartum and postpartum management for patients with CHD worldwide.

Chronic thromboembolic pulmonary hypertension is associated with a loss of total lung volume on computed tomography

BACKGROUND Although lung volumes are usually normal in individuals with chronic thromboembolic pulmonary hypertension(CTEPH),approximately 20%-29%of patients exhibit a restrictive pattern on pulmonary function testing.AIM To quantify longitudinal changes in lung volume and cardiac cross-sectional area(CSA)in patients with CTEPH.METHODS In a retrospective cohort study of patients seen in our hospital between January 2012 and December 2019,we evaluated 15 patients with CTEPH who had chest computed tomography(CT)performed at baseline and after at least 6 mo of therapy.We matched the CTEPH cohort with 45 control patients by age,sex,and observation period.CT-based lung volumes and maximum cardiac CSAs were measured and compared using the Wilcoxon signed-rank test and the Mann-Whitney u test.RESULTS Total,right lung,and right lower lobe volumes were significantly reduced in the CTEPH cohort at follow-up vs baseline(total,P=0.004;right lung,P=0.003;right lower lobe;P=0.01).In the CTEPH group,the reduction in lung volume and cardiac CSA was significantly greater than the corresponding changes in the control group(total,P=0.01;right lung,P=0.007;right lower lobe,P=0.01;CSA,P=0.0002).There was a negative correlation between lung volume change and cardiac CSA change in the control group but not in the CTEPH cohort.CONCLUSION After at least 6 mo of treatment,CT showed an unexpected loss of total lung volume in patients with CTEPH that may reflect continued parenchymal remodeling.

Research progress in the etiology of pulmonary hypertension

Pulmonary hypertension(PH)is a progressive disorder affecting the pulmonary circulation,characterized by a grim prognosis that often culminates in right heart failure and mortality.Pulmonary vascular remodeling stands out as the predominant feature in the pathogenesis and pathological alterations of PH.Whereas,the pathogenic factors of PH are intricate,involving multiple interacting elements,and the mechanism behind pulmonary vascular remodeling remains not entirely comprehended.In this context,inflammation,chemokines,and gut microbiota may make a intricate and interrelated difference during the process of pulmonary vascular remodeling.

“Treat-Repair-Treat”:Management of Left Main Coronary Compression by a Pulmonary Artery Aneurysm in a Patient with Atrial Septal Defect and Significant Pulmonary Hypertension

Left main coronary compression syndrome(LMCS)may complicate pulmonary artery aneurysms(PAA),usually developed in the context of pulmonary arterial hypertension(PAH).We report the case of a 51-year-old female patient with an atrial septal defect(unsuitable for device closure)complicated by a PAA generating a 90%left main stenosis.The significant PAH held us back from immediate surgery.After specific dual PAH-targeted therapy(sildenafil and bosentan),the atrial septal defect could be closed with a unidirectional valved patch;the PAAinduced LMCS was treated by reductive arterioplasty.The postoperative course was uneventful.Follow-up showed clinical improvement,but PAH treatment was still needed.After three months,coronary angiography showed only an insignificant residual left main stenosis,proving that reductive pulmonary arterioplasty was effective in treating LMCS.Any PAA requires further evaluation for LMCS,a dangerous but treatable complication.The“treat-repair-treat”strategy and shunt-closure with a unidirectional valved patch can both improve surgical prospects of LMCS with shunt-related PAH.

Bosentan Is Associated with a Reduction in Right Ventricular Systolic Pressure N-Terminal Pro-Hormone B-Type Natriuretic Peptide Levels in Young Patients with Pulmonary Hypertension

Pulmonary hypertension is a rare and potentially fatal disease in children if left untreated. Emerging therapies, including Bosentan, a dual endothelin receptor antagonist, have shown significant benefits in the adult pulmonary hypertension population;however, few studies have assessed the efficacy and safety of endothelin receptor antagonists in infants and young children. Our study was a single-center retrospective analysis of patients less than two years of age with a confirmed diagnosis of pulmonary hypertension and initiated on Bosentan therapy between 2017 and 2020. Twelve cases met eligibility criteria. Demographic data, laboratory data, echocardiographic, and cardiac catheterization data were analyzed. With treatment, there was a statistically significant decrease in mean right ventricular systolic pressure estimated by the tricuspid regurgitation jet (79 ± 23 mmHg reduced to 52 ± 25 mmHg;p < 0.001) N-terminal pro-hormone B-type natriuretic peptide levels (21,071 reduced to 2,037;p < 0.001). Additionally, improvement and eventual normalization of right ventricular function and septal geometry was seen within the first four months of therapy. Patients who underwent cardiac catheterization after therapy initiation (n = 4) demonstrated hemodynamic improvements;however, only the decrease in diastolic pulmonary artery pressure was statistically significant (p = 0.018). No significant differences in hemoglobin, platelet count, or liver function tests were observed between groups. In conclusion, these data suggest that Bosentan may be an effective and relatively safe treatment option for children less than two years of age with pulmonary hypertension. Further long-term randomized control studies are necessary to validate the potential clinical benefit of utilizing this drug therapy in young children.

Prevalence of pulmonary hypertension among children with Down syndrome:A systematic review and meta-analysis

BACKGROUND Pulmonary hypertension(PH)has serious short-and long-term consequences.PH is gaining increasing importance in high risk groups such as Down syndrome(DS)as it influences their overall survival and prognosis.Hence,there is a dire need to collate the prevalence rates of PH in order to undertake definitive measures for early diagnosis and management.AIM To determine the prevalence of PH in children with DS.METHODS The authors individually conducted a search of electronic databases manually(Cochrane library,PubMed,EMBASE,Scopus,Web of Science).Data extraction and quality control were independently performed by two reviewers and a third reviewer resolved any conflicts of opinion.The words used in the literature search were“pulmonary hypertension”and“pulmonary arterial hypertension”;“Down syndrome”and“trisomy 21”and“prevalence”.The data were analyzed by Comprehensive Meta-Analysis Software Version 2.Risk of bias assessment and STROBE checklist were used for quality assessment.RESULTS Of 1578 articles identified,17 were selected for final analysis.The pooled prevalence of PH in these studies was 25.5%.Subgroup analysis was carried out for age,gender,region,year of publication,risk of bias and etiology of PH.CONCLUSION This review highlights the increasing prevalence of PH in children with DS.It is crucial for pediatricians to be aware of this morbid disease and channel their efforts towards earlier diagnosis and successful management.Community-based studies with a larger sample size of children with DS should be carried out to better characterize the epidemiology and underlying etiology of PH in DS.

Pachymic Acid Ameliorates Pulmonary Hypertension by Regulating Nrf2-Keap1-ARE Pathway

Objective:Pulmonary hypertension(PH)is a severe pulmonary vascular disease that eventually leads to right ventricular failure and death.The purpose of this study was to investigate the mechanism by which pachymic acid(PA)pretreatment affects PH and pulmonary vascular remodeling in rats.Methods:PH was induced via hypoxia exposure and administration of PA(5 mg/kg per day)in male Sprague-Dawley rats.Hemodynamic parameters were measured using a right ventricular floating catheter and pulmonary vascular morphometry was measured by hematoxylin-eosin(HE),a-SMA and Masson staining.MTT assays and EdU staining were used to detect cell proliferation,and apoptosis was analyzed by TUNEL staining.Western blotting and immunohistochemistry were used to detect the expression of proteins related to the Nrf2-Keapl-ARE pathway.

Mesenchymal Stem Cells Attenuate Vascular Remodeling in Monocrotaline-induced Pulmonary Hypertension Rats

Intravenous and intratracheal implantation of mesenchymal stem cells (MSCs) may offer ameliorating effects on pulmonary hypertension (PH) induced by monocrotaline (MCT) in rats. The aim of this study was to examine the anti-remodeling effect of intravenous MSCs (VMSCs) and intratracheal MSCs (TMSCs) in rats with PH, and the underlying mechanisms. MSCs were isolated from rat bone marrow and cultured. PH was induced in rats by intraperitoneal injection of MCT. One week after MCT administration, the rats were divided into 3 groups in terms of different treatments: VMSCs group (intravenous injection of MSCs), TMSCs group (intratracheal injection of MSCs), PH group (no treatment given). Those receiving saline instead of MCT served as negative control (control group). Pulmonary arterial structure was pathologically observed, pulmonary arterial dynamics measured, and remodeling-associated cytokines Smad2 and Smad3 detected in the lungs, three weeks after MCT injection. The results showed that PH group versus control group had higher pulmonary arterial pressure (PAP) and wall thickness index (WTI) 21 days after MCT treatment. The expression of phosphorylated (p)-Smad2 and the ratio of p-Smad2/Smad2 were much higher in PH group than in control group. Fluorescence-labeled MSCs were extensively distributed in rats’ lungs in VMSCs and TMSCs groups 3 and 14 days after transplantation, but not found in the media of the pulmonary artery. WTI and PAP were significantly lower in both VMSCs and TMSCs groups than in PH group three weeks after MCT injection. The p-Smad2 expression and the ratio of p-Smad2/Smad2 were obviously reduced in VMSCs and TMSCs groups as compared with those in PH group. In conclusion, both intravenous and intratracheal transplantation of MSCs can attenuate PAP and pulmonary artery remodeling in MCT-induced PH rats, which may be associated with the early suppression of Smad2 phosphorylation via paracrine pathways.

The Role of Endogenous Carbon Monoxide in the Hypoxic Vascular Remodeling of Rat Model of Hypoxic Pulmonary Hypertension

We investigated the expression of heme oxygenase 1 (HO 1) gene and production of endogenous carbon monoxide (CO) in the rat lung tissue at different time points of chronic hypoxic pulmonary hypertension and the effect of hemin on the expression of HO 1 gene and pulmonary hypertension. A rat model of hypoxic pulmonary hypertension was recreated by exposure to intermittent normobaric hypoxic environment (10 % O 2). Reverse transcriptase polymerase chain reaction (RT PCR) was performed to determine the level of HO 1 mRNA in the rat lung tissue and double wave length spectrophotometry was used to evaluate the quantity of COHb in arterial blood. Cardiac catheterization was employed to measure the right ventricular systolic pressure (RVSP) and HE staining was performed in dissected lung tissue to observe the pathological changes of the intra acinar pulmonary arteries (IAPA). It was found that (1) There was a low level of HO 1 mRNA in normal rat lung tissue, but the level of HO 1 mRNA increased by 2-4 times in the lung tissue of hypoxic rats ( P <0.01). The quantity of COHb was 2-3 times those of control group ( P <0.01 or P <0.05). These were accompanied by the increased of RVSP and the thickened IAPA; (2) Hemin could keep the HO 1 mRNA and COHb in the hypoxic rat lung tissue at a high level, and partially suppressed the increase of rat RVSP, thereby ameliorating the pathological changes of IAPA. In conclusion, the upregulation of the expression of HO 1 gene and production of CO in the rat lung of hypoxic pulmonary hypertension plays a role of inhibition in the development of hypoxic pulmonary hypertension. Hemin has a therapeutic effect on hypoxic pulmonary hypertension.

Left atrial diameter and atrial fibrillation,but not elevated NT-proBNP,predict the development of pulmonary hypertension in patients with HFpEF

Background The determinants of pulmonary hypertension(PH)due to heart failure with preserved ejection fraction(HFpEF)have been poorly investigated in patients with cardiovascular diseases(CVD).Methods From July 12017 to March 312019,a total of 149 consecutive HFp EF patients hospitalized with CVD were enrolled in this prospective cross-sectional study.A systolic pulmonary artery pressure(PASP)>35 mm Hg estimated by echocardiography was defined as PH-HFp EF.Logistic regression was performed to establish predictors of PH in HFpEF patients.Results Overall,the mean age of participants was 72±11 years,and 74(49.7%)patients were females.A total of 59(39.6%)patients were diagnosed with PH-HFpEF by echocardiography.The left atrial diameter(LAD)was related to the ratio of the transmitral flow velocities/mitral annulus tissue velocities in early diastole(E/E’)and the left ventricular diameter in systole(LVDs).N-Terminal pro B-type natriuretic peptide(NT-proBNP)was not found to be associated with LAD and impaired diastolic or systolic function of the left ventricle.Multivariable logistic regression showed that atrial fibrillation(AF)increased the risk of PH-HFpEF incidence 3.46-fold with a 95%confidence interval(CI)of 1.44–8.32,P=0.005.Meanwhile,LAD≥45 mm resulted in a 3.43-fold increased risk,95%CI:1.51–7.75,P=0.003.However,the significance levels of NT-proBNP,age and LVEF were underpowered in the regression model.Two variables,AF and LAD≥45 mm,predicted the PH-HFpEF incidence(C-statistic=0.773,95%CI:0.695–0.852,P<0.001).Conclusions Two parameters associated with electrical and anatomical remodelling of the left atrium were related to the incidence of PH in HFpEF patients with CVD.

Terlipressin improves pulmonary pressures in cirrhotic patients with pulmonary hypertension and variceal bleeding or hepatorenal syndrome

Terlipressin has been shown to improve both pulmonary and systemic hemodynamics in stable cirrhotic patients with pulmonary hypertension,whereas other vasoconstrictors may cause pulmonary pressures to deteriorate We investigated the pulmonary and systemic hemodynamic effects of the first terlipressin dose(2 mg) in 7 cirrhotic patients with PH presenting with variceal bleeding(n=4) or hepatorenal syndrome(n=3).Terlipressin decreased pulmonary vascular resistance(158.8±8.9 vs 186.5±13.9 dynes sec cm-5 ;P=0.003) together with an increase in systemic vascular resistance(2143± 126 vs 1643±126 dynes sec cm-5 ;P<0.001).Terlipressin should be the vasoconstrictor treatment of choice when patients present with variceal bleeding or HRS.

Circular RNAs in pulmonary hypertension:Emerging biological concepts and potential mechanism

Circular RNAs(circRNAs)are endogenous RNAs with a covalently closed single-stranded transcript.They are a novel class of genomic regulators that are linked to many important development and disease processes and are being pursued as clinical and therapeutic targets.Using the most powerful RNA sequencing and bioinformatics techniques,a large number of circRNAs have been identified and further functional studies have been performed.It is known that circRNAs act as potential biomarkers,sponges for microRNAs(miRNAs)and RNA-binding proteins(RBPs),and regulators of mRNA transcription.They also participate in the translation of peptides or proteins.Many types of circRNAs are dysregulated in plasma or lung tissues,and they may be involved in regulating the proliferation and apoptosis of pulmonary artery endothelial cells(PAECs)and pulmonary artery smooth muscle cells(PASMCs),leading to pulmonary vascular remodeling in pulmonary hypertension(PH).One possible mechanism is that circRNAs can regulate the function of PAECs and PASMCs by acting as miRNA sponge.However,other potential mechanisms of action of circRNAs are still being actively explored in PH.This paper presents a systematic review of the biogenesis,biological characterization,relevant underlying functions,and future perspectives for studies of circRNAs in the pathogenesis of PH.

Experimental animal models of pulmonary hypertension:Development and challenges

Pulmonary hypertension(PH) is clinically divided into 5 major types, characterized by elevation in pulmonary arterial pressure(PAP) and pulmonary vascular resistance(PVR), finally leading to right heart failure and death. The pathogenesis of this arteriopathy remains unclear, leaving it impossible to target pulmonary vascular remodeling and reverse the deterioration of right ventricular(RV) function. Different animal models have been designed to reflect the complex mechanistic origins and pathology of PH, roughly divided into 4 categories according to the modeling methods: noninvasive models in vivo, invasive models in vivo, gene editing models, and multi-means joint modeling. Though each model shares some molecular and pathological changes with different classes of human PH, in most cases the molecular etiology of human PH is poorly known. The appropriate use of classic and novel PH animal models is essential for the hunt of molecular targets to reverse severe phenotypes.

Vascular Metabolic Mechanisms of Pulmonary Hypertension

Pulmonary hypertension(PH)is a severe and progressive disease characterized by increased pulmonary vascular resistance leading to right heart failure and death.In PH,the cellular metabolisms including those of the three major nutrients(carbohydrate,lipid and protein)are aberrant in pulmonary vascular cells.Glucose uptake,glycolysis,insulin resistance,sphingolipid S1P,PGE2,TXA2,leukotrienes and glutaminolysis are upregulated,and phospholipid-prostacyclin and L-arginine-nitric oxide pathway are compromised in lung vascular cells.Fatty acid metabolism is disordered in lung endothelial cells and smooth muscle cells.These molecular mechanisms are integrated to promote PH-specific abnormal vascular cell proliferation and vascular remodeling.This review summarizes the recent advances in the metabolic reprogramming of glucose,fatty acid,and amino acid metabolism in pulmonary vascular remodeling in PH and the mechanisms for how these alterations affect vascular cell fate and impact the course of PH.