Effects of the dual endothelin-receptor antagonist bosentan in patients with pulmonary hypertension: a randomised placebo-controlled study

A new day has come: Sotatercept for the treatment of pulmonary arterial hypertension

Despite increasing therapeutic options and evolving treatment strategies, including targeting 3 therapeutic pathways, in the management of pulmonary arterial hypertension (PAH), morbidity and mortality have remained unacceptably high. Sotatercept is a first-in-class, novel activin signaling inhibitor approved for treating PAH based on evolving efficacy and safety evidence. This state-of-the-art review summarizes the current understanding of the mechanism of action, the impact on outcomes that improve how patients feel, function, and survive, and the safety and adverse event profile to inform readers of this breakthrough novel therapy.

Treatment algorithm for pulmonary arterial hypertension

Pulmonary arterial hypertension leads to significant impairment in haemodynamics, right heart function, exercise capacity, quality of life and survival. Current therapies have mechanisms of action involving signalling via one of four pathways: endothelin-1, nitric oxide, prostacyclin and bone morphogenetic protein/activin signalling. Efficacy has generally been greater with therapeutic combinations and with parenteral therapy compared with monotherapy or nonparenteral therapies, and maximal medical therapy is now four-drug therapy. Lung transplantation remains an option for selected patients with an inadequate response to therapies.

Towards a Better Prognosis in Patients with Systemic Sclerosis-Related Pulmonary Arterial Hypertension: Recent Developments and Perspectives

Precapillary pulmonary hypertension (PH) is a significant complication of systemic sclerosis (SSc). It represents one of the leading causes of morbidity and mortality, correlating with a significantly dismal prognosis and quality of life. Despite advancements in the management of patients with pulmonary arterial hypertension associated with SSc (SSc-PAH), no significant improvement has been reported in survival of patients with precapillary SSc-PH associated with extensive lung parenchyma disease. International expert consensus and guidelines for the management of PH recommend annual screening of SSc patients for early detection of pre-capillary PH. The implementation of screening algorithms capable of identifying patients with a high likelihood of developing PH could help limit unnecessary right-heart catheterization procedures and prevent significant delay in diagnosis. Furthermore, early initiation of up-front combination targeted therapy in patients with PAH has shown increase in survival rates, indicating that timely and aggressive medical therapy is key for stabilizing and even improving functional class, hemodynamic parameters and 6 min walking distance (6MWD) in this population. Further research is warranted into the benefit of PAH-targeted therapies in patients with PH associated with lung disease. Lastly, we discuss the potential role of immunosuppression using biologic agents in the therapeutic management of precapillary PH in SSc patients.

Calcium channel blockers in patients with pulmonary arterial hypertension receiving PAH-specific treatment

BACKGROUND

Calcium channel blockers (CCB) are the first effective therapy for vasoreactive patients with idiopathic pulmonary arterial hypertension (IPAH). However, the advent of modern PAH-specific drugs may undermine the role of vasoreactivity tests and CCB treatment. We aimed to clarify the effect of acute vasoreactivity testing and CCB on patients with IPAH receiving PAH-specific treatment.

METHODS

We retrospectively investigated consecutive patients with IPAH (n = 136) diagnosed between 2000 and 2020 and collected data from patients who underwent acute vasoreactivity testing using inhaled nitric oxide (NO). The effects of vasoreactivity testing and CCB therapy were reviewed. Long-term survival was analysed using the Kaplan-Meier method.

RESULTS

Acute vasoreactivity testing was performed in 49% of patients with IPAH (n = 67), including 23 patients (34%) receiving PAH-specific therapy without vasoreactivity testing. Eight patients (12%), including three patients (4.4%) receiving PAH-specific therapy, presented acute responses at vasoreactivity testing. They received high-dose CCB therapy (CCB monotherapy for five patients [7.5%] and CCB therapy and PAH-specific therapy for three patients [4.4%]). They presented a significant improvement in clinical parameters and near-normalisation of haemodynamics (mean pulmonary arterial pressure decreased from 46 [interquartile range: 40-49] to 19.5 [interquartile range: 18-23] mmHg [P < .001] at 1-year follow-up). All eight vasoreactive responders receiving CCB therapy showed better long-term survival than non-responders treated with PAH-specific therapy (P < .001).

CONCLUSIONS

CCB therapy benefited patients with IPAH who showed acute response to vasoreactivity testing using inhaled NO, even when receiving modern PAH-specific therapy. Acute vasoreactive responders may benefit more from CCB than from PAH-specific therapy.

Removing the FDA's Boxed Hepatotoxicity Warning and Liver Function Testing Requirement for Ambrisentan

Importance

Endothelin receptor antagonists are first-line therapy for pulmonary arterial hypertension (PAH). The first 2 agents approved in the class, bosentan and ambrisentan, initially carried boxed warnings for hepatotoxicity and required monthly liver function tests (LFTs) as part of a risk evaluation and mitigation strategy (REMS); however, in 2011, as further safety data emerged on ambrisentan, the boxed hepatotoxicity warning and LFT requirements were removed.

Objective

To analyze changes in the use of and LFT monitoring for ambrisentan and bosentan after changes to the ambrisentan labeling and REMS.

Design, Setting, and Participants

This serial cross-sectional study used data from 3 longitudinal health care insurance claims databases-Medicaid, Optum's deidentified Clinformatics Data Mart, and Merative Marketscan-to perform an interrupted time series analysis of prescription fills and LFTs for patients taking ambrisentan and bosentan. Participants were patients filling prescriptions for ambrisentan and bosentan from July 1, 2007, to December 31, 2018. Data analysis was performed from April 2021 to August 2023.

Exposure

Removal of the boxed warning for hepatotoxicity and the REMS LFT monitoring requirements on ambrisentan in March 2011.

Main Outcomes and Measures

The primary outcomes were use of ambrisentan (ie, individuals with at least 1 dispensing per 1 000 000 individuals enrolled in the 3 datasets) vs bosentan and LFT monitoring (ie, proportion of initiators with at least 1 ordered test) before initiation and before the first refill.

Results

A total of 10 261 patients received a prescription for ambrisentan during the study period (7442 women [72.5%]; mean [SD] age, 52.6 [17.6] years), and 11 159 patients received a prescription for bosentan (7931 women [71.1%]; mean [SD] age, 47.7 [23.7] years). Removal of the ambrisentan boxed hepatotoxicity warning and LFT monitoring requirement was associated with an immediate increase in the use of ambrisentan (1.50 patients per million enrollees; 95% CI, 1.08 to 1.92 patients per million enrollees) but no significant change in the use of bosentan. There were reductions in recorded LFTs before drug initiation (13.1% absolute decrease; 95% CI, -18.2% to -8.0%) and before the first refill (26.4% absolute decrease; 95% CI, -34.4% to -18.5%) of ambrisentan but not bosentan.

Conclusions and Relevance

In this serial cross-sectional study of ambrisentan, labeling changes and removal of the REMS-related LFT requirement were associated with shifts in prescribing and testing behavior for ambrisentan but not bosentan. Further clinician education may be needed to maximize the benefits of REMS programs and labeling warnings designed to ensure the safe administration of high-risk medications.

Comparison of Different Treatments of Persistent Pulmonary Hypertension of the Newborn: A Systematic Review and Network Meta-Analysis

OBJECTIVES

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening disease. Despite being considered the gold standard treatment scheme, inhaled nitric oxide (iNO) is not readily available in settings with limited resources. Therefore, in recent years, research on related drugs is being actively pursued. Herein, we aimed to use random-effects network meta-analysis to evaluate the efficacy and associated mortality of different PPHN therapies.

DATA SOURCES

We electronically searched the PubMed, Embase, and Cochrane Library for data up to January 27, 2023.

STUDY SELECTION

Randomized controlled trials involving neonates with PPHN assessing efficacy and mortality of various treatments.

DATA EXTRACTION

Details of study population, treatments, and outcomes were extracted.

DATA SYNTHESIS

Direct pairwise comparisons and a network meta-analysis was performed under random effects. The ranking probability was further assessed based on the surface under the cumulative ranking curve (SUCRA). We analyzed 23 randomized clinical trials involving 902 newborns with PPHN. Sixteen different treatment strategies were compared with each other and conventional therapy (CON). A median concentration of 10-20 parts per million (ppm) iNO (MNO) coupled with sildenafil orally administered at a dose of 1-3 mg/kg/dose every 6-8 hours (OSID) demonstrated the best efficacy (MNO + OSID vs. CON: odds ratio [OR] = 27.53, 95% CI, 2.36-321.75; SUCRA = 0.818, ranking first; moderate quality). OSID combined with milrinone administered IV also performed well in terms of efficacy (OSID + milrinone vs. CON: OR = 25.13, 95% CI = 1.67-377.78; SUCRA = 0.811, ranking second; low quality) and mortality reduction (CON vs. OSID + milrinone: OR = 25.13, 95% CI = 1.67-377.78; SUCRA = 0.786, ranking last; low quality).

CONCLUSIONS

MNO + OSID is the most effective PPHN treatment. If iNO is not available, OSID + milrinone is preferred.

A comprehensive analysis of liver safety across zibotentan oncology trials: knowledge of the past offers new perspectives on the present

BACKGROUND

Endothelin receptor antagonists (ERAs) are associated with liver injury. We used data from previous oncology clinical trials to determine the liver safety profile of zibotentan, which is currently in clinical development (in combination with dapagliflozin) for chronic kidney disease and cirrhosis.

RESEARCH DESIGN AND METHODS

Six global, double-blinded, phase 2b and 3 clinical trials from the zibotentan oncology development program were pooled to analyze liver safety. Descriptive statistics, proportion of liver-related adverse events, liver biochemistry parameter elevation, and shifts from baseline were analyzed, with individual case assessment.

RESULTS

A total of 1532 patients received zibotentan for 285 days (mean), and 1486 patients received placebo for 320 days (mean). The frequency of any hepatic disorder preferred term was similar across zibotentan monotherapy (22/947 patients, 2.3%) and placebo monotherapy arms (30/881 patients, 3.4%). A total of 4 (0.4%) patients receiving zibotentan monotherapy experienced ALT elevations >5× ULN versus 8 (0.9%) receiving placebo. Of the seven patients receiving zibotentan who met criteria for potential Hy's Law, there were no cases of drug-induced liver injury.

CONCLUSIONS

We found no evidence of zibotentan-related liver biochemistry changes among cancer-treated patients, suggesting that hepatotoxicity of ERAs is molecule-dependent, and allowing exploration of zibotentan for new indications.

CGRP attenuates pulmonary vascular remodeling by inhibiting the cGAS-STING-NFκB pathway in pulmonary arterial hypertension

BACKGROUND

Hyperproliferation, inflammation, and mitochondrial abnormalities in pulmonary artery smooth muscle cells (PASMCs) underlie the pathological mechanisms of vascular remodeling in pulmonary arterial hypertension (PAH). Cytoplasmic mtDNA activates the cGAS-STING-NFκB pathway and secretes pro-inflammatory cytokines that may be involved in the pathogenesis of PAH. Calcitonin gene-related peptide (CGRP) acts as a vasodilator to regulate patterns of cellular energy metabolism and has vasodilatory and anti-inflammatory effects.

METHODS

The role of the cGAS-STING-NFκB signaling pathway in PAH vascular remodeling and the regulation of CGRP in the cGAS-STING-NFκB signaling pathway were investigated by echocardiography, morphology, histology, enzyme immunoassay, and fluorometry.

RESULTS

Monocrotaline (MCT) could promote right heart hypertrophy, pulmonary artery intima thickening, and inflammatory cell infiltration in rats. Cinnamaldehyde (CA)-induced CGRP release alleviates MCT-induced vascular remodeling in PAH. CGRP reduces PDGF-BB-induced proliferation, and migration, and downregulates smooth muscle cell phenotypic proteins. In vivo and in vitro experiments confirm that the mitochondria of PASMCs were damaged during PAH, and the superoxide and mtDNA produced by injured mitochondria activate the cGAS-STING-NFκB pathway to promote PAH process, while CGRP could play an anti-PAH role by protecting the mitochondria and inhibiting the cGAS-STING-NFκB pathway through PKA.

CONCLUSION

This study identifies that CGRP attenuates cGAS-STING-NFκB axis-mediated vascular remodeling in PAH through PKA.

Pulmonary Hypertension in Underrepresented Minorities: A Narrative Review

Minoritized racial and ethnic groups suffer disproportionately from the incidence and morbidity of pulmonary hypertension (PH), as well as its associated cardiovascular, pulmonary, and systemic conditions. These disparities are largely explained by social determinants of health, including access to care, systemic biases, socioeconomic status, and environment. Despite this undue burden, minority patients remain underrepresented in PH research. Steps should be taken to mitigate these disparities, including initiatives to increase research participation, combat inequities in access to care, and improve the treatment of the conditions associated with PH.

Bosentan attenuates sickle cell disease erythrocyte HbS polymerization and impaired deformability induced by endothelin-1

The effects of endothelin-1 (ET-1) on erythrocytes from sickle cell disease (SCD) patients have been described, but mechanisms of ET-1 regarding primary erythrocyte functions remain unknown. ET-1 is a vasoconstrictor peptide produced by endothelial cells, and the expression of ET-1 is increased in SCD. The present study used ex vivo experiments with sickle cell erythrocytes, ET-1, and bosentan, a dual antagonist of ETA and ETB receptors. We performed a hemoglobin S (HbS) polymerization assay with three concentrations of ET-1 (1, 20, and 50 pg/mL) and bosentan (100 nmol/L). ET-1 increased HbS polymerization at all concentrations, and this effect was suppressed by bosentan. For the deformability assay, red blood cells (RBCs) were incubated on a Sephacryl column with the same concentrations of ET-1 and bosentan. ET-1 decreased deformability, and this effect was reversed by bosentan. To observe erythrocyte adhesion, ET-1 and bosentan were incubated with RBCs in thrombospondin-coated 96-well plate, which demonstrated that ET-1 decreased adhesion but that bosentan enhanced adhesion. We also assessed erythrocyte apoptosis and observed decreased eryptosis induced by ET-1, and these effects were inhibited bosentan. Thus, these findings demonstrated that ET-1 modulates HbS polymerization, erythrocyte deformability, adhesion to thrombospondin, and eryptosis, and these effects were suppressed or enhanced by bosentan.

Long-term safety of macitentan in patients with pulmonary hypertension: A meta-analysis of randomised controlled trials

BACKGROUND

Macitentan has demonstrated its effectiveness in patients with pulmonary hypertension (PH), but its safety, especially for long-term use, needs to be further explored. This systematic review and meta-analysis aimed to determine the safety of long-term use of macitentan in patients with PH.

METHODS

A systematic search was made of PubMed, Embase, Cochrane Library and clinicaltrials.gov, without language restrictions. Randomised controlled trials (RCTs) on treatment of PH with macitentan, compared with placebo, were reviewed. Estimated effects of included studies were pooled as risk ratios (RRs), with 95% confidence intervals (CIs).

RESULTS

Six RCTs (enrolling 1003 participants) met the inclusion criteria. Anaemia (RR 3.86, 95% CI 2.05-7.30), headache (RR 1.52, 95% CI 1.02-2.26) and bronchitis (RR 2.24, 95% CI 1.30-3.87) were more frequent in the macitentan groups. There was no statistically significant difference in the proportion of patients with at least one adverse event (AE) or serious adverse event (SAE), AEs leading to discontinuation of study treatment, all-cause death, right ventricular failure (RVF) and peripheral oedema between the two groups.

CONCLUSIONS

The long-term use of macitentan is safe for patients with PH, although with a higher risk of anaemia, headache and bronchitis.

Impact of Parenteral Prostanoids in Pulmonary Arterial Hypertension: The Relevance of Timing

Parenteral prostanoids are being recommended in pulmonary arterial hypertension (PAH) treatment, but the prognostic relevance of delayed treatment initiation is still debated. This study assessed the impact of the timing of prostacyclin treatment initiation on reducing PVR and achieving a low-risk profile in PAH patients. The study enrolled 151 patients who started on parenteral prostanoids with different treatment strategies. All patients underwent right heart catheterization, clinical evaluation, and risk assessments at baseline and after 1-year follow-up. Patients with an upfront strategy including parenteral prostanoid plus one oral drug had -5.3 ± 6.2 WU (-50 ± 19%) reduction in PVR, patients with an upfront strategy including parenteral prostanoid plus double oral drug had -12.8 ± 5.9 WU (-68 ± 17%) reduction in PVR, while patients with an add-on strategy including parenteral prostanoid after oral drugs had -3.9 ± 3.5 WU (-23 ± 19%) reduction in PVR. An upfront strategy including parenteral prostanoids was independently associated with an increased likelihood of achieving the greater reduction of PVR compared with an add-on strategy. Additionally, the greater the severity of PH at the time of diagnosis, in terms of PVR and RV reverse remodeling, the higher the probability of treatment failure. An upfront strategy including a parenteral prostanoid is associated with the highest likelihood of achieving a low-risk profile and a greater reduction of PVR compared with parenteral prostanoid as an add-on to oral treatment.

Role of prostanoids, nitric oxide and endothelin pathways in pulmonary hypertension due to COPD

Pulmonary hypertension (PH) due to chronic obstructive pulmonary disease (COPD) is classified as Group 3 PH, with no current proven targeted therapies. Studies suggest that cigarette smoke, the most risk factor for COPD can cause vascular remodelling and eventually PH as a result of dysfunction and proliferation of pulmonary artery smooth muscle cells (PASMCs) and pulmonary artery endothelial cells (PAECs). In addition, hypoxia is a known driver of pulmonary vascular remodelling in COPD, and it is also thought that the presence of hypoxia in patients with COPD may further exaggerate cigarette smoke-induced vascular remodelling; however, the underlying cause is not fully understood. Three main pathways (prostanoids, nitric oxide and endothelin) are currently used as a therapeutic target for the treatment of patients with different groups of PH. However, drugs targeting these three pathways are not approved for patients with COPD-associated PH due to lack of evidence. Thus, this review aims to shed light on the role of impaired prostanoids, nitric oxide and endothelin pathways in cigarette smoke- and hypoxia-induced pulmonary vascular remodelling and also discusses the potential of using these pathways as therapeutic target for patients with PH secondary to COPD.

Recent Advances in the Treatment of Pulmonary Arterial Hypertension Associated with Connective Tissue Diseases

Pulmonary hypertension (PH) is a severe vascular complication of connective tissue diseases (CTD). Patients with CTD may develop PH belonging to diverse groups: (1) pulmonary arterial hypertension (PAH), (2) PH due to left heart disease, (3) secondary PH due to lung disease and/or hypoxia and (4) chronic thromboembolic pulmonary hypertension (CTEPH). PAH most often develops in systemic scleroderma (SSc), mostly in its limited variant. PAH-CTD is a progressive disease characterized by poor prognosis. Therefore, early diagnosis should be established. A specific treatment for PAH-CTD is currently available and recommended: prostacyclin derivative (treprostinil, epoprostenol, iloprost, selexipag), nitric oxide and natriuretic pathway: stimulators of soluble guanylate cyclase (sGC: riociguat) and phosphodiesterase-five inhibitors (PDE5i: sildenafil, tadalafil), endothelin receptor antagonists (ERA: bosentan, macitentan, ambrisentan). Moreover, novel drugs, e.g., sotatercept, have been intensively investigated in clinical trials. We aim to review the literature on recent advances in the treatment strategy and prognosis of patients with PAH-CTD. In this manuscript, we discuss the mechanism of action of PAH-specific drugs and new agents and the latest research conducted on PAH-CTD patients.

Pharmacotherapy of refractory pulmonary arterial hypertension

INTRODUCTION

Treatment of refractory pulmonary arterial hypertension (PAH) is challenging and rarely the focus of reviews. The purpose of this review is to discuss current treatment options of refractory PAH, along with the state of research of several new medications.

AREAS COVERED

We conducted a comprehensive PubMed search on the relevant literature on treating PAH, with a focus on approved and investigational interventions for high-risk patients. Our strategy used keywords 'Treatment' AND 'Pulmonary Hypertension,' without date restrictions, ensuring a thorough survey of available literature for our review.

EXPERT OPINION

By utilizing serial risk assessment to identify patients remaining intermediate or high-risk, more patients are likely to survive longer. This is done by earlier use of combination or triple therapy with prostacyclin drugs. Current medications for PAH are all essentially vasodilators that improve physiology, but do not truly modify the disease process. The potential application of new investigational medications is exciting as they work by novel pathways likely to change the landscape of refractory PAH treatment.

Pharmacological management of connective tissue disease-associated pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a severe, progressive pulmonary vasculopathy (Group 1 Pulmonary Hypertension (PH)) that complicates the course of many connective tissue diseases (CTD). Detailed testing is required to differentiate PAH from other types of PH caused by CTD such as left heart disease (Group 2 PH), pulmonary parenchymal disease (Group 3 PH), and chronic thromboembolic pulmonary hypertension (Group 4 PH). PAH is most frequently seen in systemic sclerosis but can also be seen with systemic lupus erythematosus, mixed CTD, and primary Sjogren's syndrome.

AREAS COVERED

This review discusses the epidemiology of CTD-associated PAH, outlines the complex diagnosis approach, and finishes with an in-depth discussion on the current treatment paradigm. Focus is placed on challenges faced in the treatment of CTD-associated PAH, (decreased efficacy and poorer tolerance of pharmacological therapies) and includes a discussion on the future investigational treatments.

EXPERT OPINION

Despite significant advances over the past decades with more aggressive treatment algorithms, CTD-associated PAH patients continue to have poorer survival compared to those with idiopathic PAH. This review highlights factors leading to disparate outcomes compared to other forms of PAH, and discusses on further improvements that may increase quality of life and survival for CTD-associated PAH patients.

Development and pharmacokinetic evaluation of Neusilin® US2-based S-SNEDDS tablets for bosentan: Fasted and fed states bioavailability, IVIS® real-time biodistribution, and ex-vivo imaging

The study reported here aimed to develop and optimize the S-SNEDDS tablet of bosentan (BOS) and to investigate its pharmacokinetic and biodistribution properties. The BOS-loaded SNEDDS have been developed and characterized in a previous study. The BOS-loaded SNEDDS formulation was converted to S-SNEDDS using Neusilin® US2. The S-SNEDDS tablets were obtained using the direct compression technique, and in vitro dissolution, in vitro lipolysis, and ex-vivo permeability studies of the tablets were performed. The S-SNEDDS tablet and reference tablet (Tracleer®) were administered to male Wistar rats at 50 mg/kg dose by oral gavage in fasted and fed state conditions. The biodistribution of the S-SNEDDS tablet was investigated in Balb/c mice using fluorescent dye. The tablets were dispersed in distilled water before administration to animals. The relationship between in vitro dissolution data and in vivo plasma concentration was examined. The S-SNEDDS tablets showed 2.47, 7.49, 3.70, and 4.39 increases in the percentages of cumulative dissolution in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively, when compared to the reference, and increased the Cmax and AUC 2.65 and 1.28-fold and 4.73 and 2.37-fold in fasted and fed states, respectively, when compared to the reference. S-SNEDDS tablets also significantly reduced interindividual variability in both fasted and fed states (p < 0.05). The XenoLight™ DiR and VivoTag® 680XL labeled S-SNEDDS tablet formulation increased the real-time biodistribution in the body by factors of 2.4 and 3.4 and organ uptake and total emission increased by factors of 2.8 and 3.1, respectively. The IVIVR has been successfully established for S-SNEDDS tablets (R2 > 0.9). The present study confirms the potential of the S-SNEDDS tablet to enhance the in vitro and in vivo performance of BOS.

Lung Transplantation for Pulmonary Arterial Hypertension: Optimized Referral and Listing Based on an Evolving Disease Concept

Pulmonary hypertension (PH) was once a devastating and fatal disease entity, the outlook of which has been significantly improved by the continued progress of medical treatment algorithms. However, some patients still ultimately fail to achieve an adequate clinical response despite receiving maximal medical treatment. Historically, lung transplantation (LTx) has been the only effective therapeutic option that could lead to satisfactory outcomes and save these advanced patients' lives. However, patients with PH tend to have the highest mortality rates on the transplant waiting list; especially after comprehensive medical treatment, they continue to deteriorate very rapidly, eventually missing optimal transplantation windows. Balancing optimized medical treatment with the appropriate timing of referral and listing has been highly controversial in LTx for patients with PH. The 2021 consensus document for the selection of lung transplant candidates from the International Society for Heart and Lung Transplantation (ISHLT) updated the specific recommendations for the LTx referral and listing time for patients with PH based on objective risk stratification. Herein, we review the evolving PH-related concepts and highlight the optimization of LTx referral and listing for patients with PH, as well as their management on the waiting list.

Bioinformatics exploration of potential common therapeutic targets for systemic and pulmonary arterial hypertension-induced myocardial hypertrophy

Systemic and pulmonary arterial hypertension (PAH) can induce left and right ventricular hypertrophy, respectively, but common therapeutic targets for both left and right hypertrophy are limited. In this study, we attempt to explore potential common therapeutic targets and screen out potential target drugs for further study. Cardiac mRNA expression profiles in mice with transverse aortic constriction (TAC) and pulmonary arterial constriction (PAC) are obtained from online databases. After bioinformatics analyses, we generate TAC and PAC mouse models to validate the phenotypes of cardiac remodelling as well as the identified hub genes. Bioinformatics analyses show that there are 214 independent differentially expressed genes (DEGs) in GSE136308 (TAC related) and 2607 independent DEGs in GSE30922 (PAC related), while 547 shared DEGs are associated with the function of the extracellular matrix (ECM) or involved in the PI3K-Akt signaling pathway, cytokine-cytokine receptor interactions, and ECM-receptor interactions. We identifyd Fn1, Il6, Col1a1, Igf1, Col1a2, Timp1, Col3a1, Cd44, Ctgf and Postn as hub genes of the shared DEGs, and most of them are associated with myocardial fibrosis. Those hub genes and phenotypes of cardiac remodelling are validated in our TAC and PAC mouse models. Furthermore, we identify dehydroisoandrosterone (DHEA), iloprost and 4,5-dianilinophthalimide (DAPH) as potential therapeutic drugs targeting both left and right ventricular hypertrophy and validate the effect of DHEA. These findings suggest that DHEA could be an effective drug for pressure overload-induced left or right ventricular hypertrophy by regulating the shared hub differentially expressed genes associated with fibrosis.

Novel Drugs for the Treatment of Pulmonary Arterial Hypertension: Where Are We Going?

Pulmonary arterial hypertension (PAH) is a progressive disease that despite advances in therapy is associated with a 7-year survival of approximately 50%. Several risk factors are associated with developing PAH, include methamphetamine use, scleroderma, human immunodeficiency virus, portal hypertension, and genetic predisposition. PAH can also be idiopathic. There are traditional pathways underlying the pathophysiology of PAH involving nitric oxide, prostacyclin, thromboxane A2, and endothelin-1, resulting in impaired vasodilation, enhanced vasoconstriction and proliferation in the pulmonary vasculature. Established PAH medications targets these pathways; however, this paper aims to discuss novel drugs for treating PAH by targeting new and alternative pathways.

Importance of the Mean Rate of Pressure Change of the Pulmonary Artery (dP/dt mean PA) in Patients with Pulmonary Arterial Hypertension

Background  Pulmonary arterial hypertension (PAH) is a rare disease of cardiopulmonary circulation characterized by elevated pressure in the pulmonary artery. The right-heart catheter is the gold standard for diagnosis, but there is interest in identifying additional prognostic indicators. The aim of this study was to examine the importance of the rate of pressure change of the pulmonary artery (dP/dt mean PA) in patients with PAH. Methods  We retrospectively analyzed data from 142 patients with PAH (exclusively clinical group 1) and examined the statistical correlation of dP/dt mean PA with vascular, right ventricular, and clinical parameters. Data was collected mostly from the right heart catheterization and the transthoracal echocardiography at presentation. Results  dP/dt mean PA showed a significant correlation with systolic pressure of the pulmonary artery ( n = 142, R ²  = 56%, p  < 0.001), pulmonary vascular resistance ( n  = 142, R ²  = 51%, p  < 0.001), the rate of pressure change in the right ventricle ( n  = 142, R ²  = 53%, p  < 0.001), and the right ventricular fractional area change ( n  = 110, R ²  = 51%, p  < 0.001). Receiver operating characteristic curve analysis showed that dP/dt mean PA had the highest prognostic value in predicting increase in the 6-minute walk test and decrease in the N-terminal-probrain natriuretic peptide after the initiation of PAH therapy, with an area under the curve of 0.73. Conclusion  Our findings suggest that dP/dt mean PA may be a useful prognostic indicator in the treatment of patients with PAH, and further research is warranted to validate this parameter.

Pharmacotherapy for Pulmonary Hypertension in Infants with Bronchopulmonary Dysplasia: Past, Present, and Future

Approximately 8-42% of premature infants with chronic lung disease of prematurity, bronchopulmonary dysplasia (BPD), develop pulmonary hypertension (PH). Infants with BPD-PH carry alarmingly high mortality rates of up to 47%. Effective PH-targeted pharmacotherapies are desperately needed for these infants. Although many PH-targeted pharmacotherapies are commonly used to treat BPD-PH, all current use is off-label. Moreover, all current recommendations for the use of any PH-targeted therapy in infants with BPD-PH are based on expert opinion and consensus statements. Randomized Control Trials (RCTs) are needed to determine the efficacy of PH-targeted treatments in premature infants with or at risk of BPD-PH. Prior to performing efficacy RCTs, studies need to be conducted to obtain pharmacokinetic, pharmacodynamic, and safety data for any pharmacotherapy used in this understudied and fragile patient population. This review will discuss current and needed treatment strategies, identify knowledge deficits, and delineate both challenges to be overcome and approaches to be taken to develop effective PH-targeted pharmacotherapies that will improve outcomes for premature infants with or at risk of developing BPD-PH.

Metabolomic Signatures Associated With Pulmonary Arterial Hypertension Outcomes

BACKGROUND

Pulmonary arterial hypertension (PAH) is a complex disease characterized by progressive right ventricular (RV) failure leading to significant morbidity and mortality. Investigating metabolic features and pathways associated with RV dilation, mortality, and measures of disease severity can provide insight into molecular mechanisms, identify subphenotypes, and suggest potential therapeutic targets.

METHODS

We collected data from a prospective cohort of PAH participants and performed untargeted metabolomic profiling on 1045 metabolites from circulating blood. Analyses were intended to identify metabolomic differences across a range of common metrics in PAH (eg, dilated versus nondilated RV). Partial least squares discriminant analysis was first applied to assess the distinguishability of relevant outcomes. Significantly altered metabolites were then identified using linear regression, and Cox regression models (as appropriate for the specific outcome) with adjustments for age, sex, body mass index, and PAH cause. Models exploring RV maladaptation were further adjusted for pulmonary vascular resistance. Pathway enrichment analysis was performed to identify significantly dysregulated processes.

RESULTS

A total of 117 participants with PAH were included. Partial least squares discriminant analysis showed cluster differentiation between participants with dilated versus nondilated RVs, survivors versus nonsurvivors, and across a range of NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, REVEAL 2.0 composite scores, and 6-minute-walk distances. Polyamine and histidine pathways were associated with differences in RV dilation, mortality, NT-proBNP, REVEAL score, and 6-minute walk distance. Acylcarnitine pathways were associated with NT-proBNP, REVEAL score, and 6-minute walk distance. Sphingomyelin pathways were associated with RV dilation and NT-proBNP after adjustment for pulmonary vascular resistance.

CONCLUSIONS

Distinct plasma metabolomic profiles are associated with RV dilation, mortality, and measures of disease severity in PAH. Polyamine, histidine, and sphingomyelin metabolic pathways represent promising candidates for identifying patients at high risk for poor outcomes and investigation into their roles as markers or mediators of disease progression and RV adaptation.

No Placebo Effect beyond Regression to the Mean on the Six Minute Walk Test in Pulmonary Arterial Hypertension Trials

In drug studies, patients are often included when the disease activity is high. This will make any treatment appear to lessen disease activity, although the improvement is biased by selection. This effect is known as regression towards the mean (RTM). We aimed at investigating drug trials in Pulmonary Arterial Hypertension (PAH) using the 6-minute walking distance test (6MWD) as a primary outcome for the phenomenon of RTM. An existing registry of 43 open label studies and 23 randomized controlled trials conducted between 1990 and 2009 was used as the data source. Data analysis was carried out for 18 randomized controlled trials (RCTs) and 24 open label studies out of this registry. Data were analyzed for verum and placebo arms of the RCTs separately, as well as for the open label arms. In the verum arms, the overall effect given as 33.2 m (95% CI: 25.7; 40.6]); 6MWD was slightly lower than the effect in the observational studies, with 44.6 m (95% CI: [25.4; 63.8]). After studying and interpreting the data, we found that regression towards the mean plays only a minor role in PAH studies. In particular, placebo effects in the RCTs were negligibly small, with a mean 6MWD of -2.5 m (95% CI: [-9.8; 4.7]) in the placebo arm. Therefore, our analysis indicates that results of non-randomized observational studies can be regarded as valid tools for gaining valid clinical effects in patients with PAH.

The Evolving Management and Treatment Options for Patients with Pulmonary Hypertension: Current Evidence and Challenges

Pulmonary hypertension may develop as a disease process specific to pulmonary arteries with no identifiable cause or may occur in relation to other cardiopulmonary and systemic illnesses. The World Health Organization (WHO) classifies pulmonary hypertensive diseases on the basis of primary mechanisms causing increased pulmonary vascular resistance. Effective management of pulmonary hypertension begins with accurately diagnosing and classifying the disease in order to determine appropriate treatment. Pulmonary arterial hypertension (PAH) is a particularly challenging form of pulmonary hypertension as it involves a progressive, hyperproliferative arterial process that leads to right heart failure and death if untreated. Over the last two decades, our understanding of the pathobiology and genetics behind PAH has evolved and led to the development of several targeted disease modifiers that ameliorate hemodynamics and quality of life. Effective risk management strategies and more aggressive treatment protocols have also allowed better outcomes for patients with PAH. For those patients who experience progressive PAH with medical therapy, lung transplantation remains a life-saving option. More recent work has been directed at developing effective treatment strategies for other forms of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary hypertension due to other lung or heart diseases. The discovery of new disease pathways and modifiers affecting the pulmonary circulation is an ongoing area of intense investigation.

Efficacy and safety of switching from bosentan or ambrisentan to macitentan in pulmonary arterial hypertension: A systematic review and meta-analysis

Background

There is little evidence of the effectiveness of switching from the endothelin receptor antagonists (ERAs) bosentan and ambrisentan to a novel ERA, macitentan, in patients with pulmonary arterial hypertension (PAH). Therefore, a systematic review and meta-analysis was performed to evaluate the efficacy and safety of patients with PAH switching from other ERAs to macitentan.

Methods

We retrieved the relevant literature published before January 2022 for the meta-analysis from the PubMed, EMBASE, and Cochrane Library databases. Efficacy included changes in the 6-min walk distance (6MWD), World Health Organization functional class (WHO-FC), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, hemodynamics, echocardiography and survival.

Results

Nine studies, consisting of 408 PAH patients, that met the inclusion criteria were included. The switch from bosentan or ambrisentan to macitentan effectively increased the 6MWD by 20.71 m (95% CI: 10.35-31.07, P < 0.00001, I ² = 0%). Six months after conversion, the tricuspid annular plane systolic excursion was found to improve from 19.0 ± 4.0 to 21.0 ± 5.0 mm in adults and from 16.00 ± 5.0 to 18.25 ± 4.8 mm in children. Ordinal logistic regression showed that the WHO-FC significantly improved by 0.412 (95% CI: 0.187-0.908, P = 0.028). The switch did not show significant improvement in NT-proBNP levels. In addition, the switch was well tolerated.

Conclusion

The switch from bosentan or ambrisentan to macitentan significantly increased the 6MWD in PAH patients, improved the WHO-FC, and exerted safety benefits. The effects of the switch on NT-proBNP levels, hemodynamics, and echocardiography still need to be further confirmed.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021292554].

The evolving landscape of pulmonary arterial hypertension clinical trials

Although it is a rare disease, the number of available therapeutic options for treating pulmonary arterial hypertension has increased since the late 1990s, with multiple drugs developed that are shown to be effective in phase 3 randomised controlled trials. Despite considerable advancements in pulmonary arterial hypertension treatment, prognosis remains poor. Existing therapies target pulmonary endothelial dysfunction with vasodilation and anti-proliferative effects. Novel therapies that target proliferative vascular remodelling and affect important outcomes are urgently needed. There is need for additional innovations in clinical trial design so that all emerging candidate therapies can be rigorously studied. Pulmonary arterial hypertension trial design has shifted from short-term submaximal exercise capacity as a primary endpoint, to larger clinical event-driven trial outcomes. Event-driven pulmonary arterial hypertension trials could face feasibility and efficiency issues in the future because increasing sample sizes and longer follow-up durations are needed, which would be problematic in such a rare disease. Enrichment strategies, innovative and alternative trial designs, and novel trial endpoints are potential solutions that could improve the efficiency of future pulmonary arterial hypertension trials while maintaining robustness and clinically meaningful evidence.

Recent Advances in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease in which stenosis or obstruction of the pulmonary arteries (PAs) causes an increase in PA pressure, leading to right-sided heart failure and death. Basic research has revealed a decrease in the levels of endogenous vasodilators, such as prostacyclin, and an increase in the levels of endogenous vasoconstrictors, such as endothelin, in patients with PAH, leading to the development of therapeutic agents. Currently, therapeutic agents for PAH target three pathways that are selective for PAs: the prostacyclin, endothelin, and nitric oxide pathways. These treatments improve the prognosis of PAH patients. In this review, we introduce new drug therapies and provide an overview of the current therapeutic agents.

Medications for the treatment of pulmonary arterial hypertension: a systematic review and network meta-analysis

BACKGROUND

There is no consensus on the most effective treatments of pulmonary arterial hypertension (PAH). Our objective was to compare effects of medications for PAH.

METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrials.gov from inception to December 2021. We performed a frequentist random-effects network meta-analysis on all included trials. We rated the certainty of the evidence using the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

We included 53 randomised controlled trials with 10 670 patients. Combination therapy with endothelin receptor antagonist (ERA) plus phosphodiesterase-5 inhibitors (PDE5i) reduced clinical worsening (120.7 fewer events per 1000, 95% CI 136.8-93.4 fewer; high certainty) and was superior to either ERA or PDE5i alone, both of which reduced clinical worsening, as did riociguat monotherapy (all high certainty). PDE5i (24.9 fewer deaths per 1000, 95% CI 35.2 fewer to 2.1 more); intravenous/subcutaneous prostanoids (18.3 fewer deaths per 1000, 95% CI 28.6 fewer deaths to 0) and riociguat (29.1 fewer deaths per 1000, 95% CI 38.6 fewer to 8.7 more) probably reduce mortality as compared to placebo (all moderate certainty). Combination therapy with ERA+PDE5i (49.9 m, 95% CI 25.9-73.8 m) and riociguat (49.5 m, 95% CI 17.3-81.7 m) probably increase 6-min walk distance as compared to placebo (moderate certainty).

CONCLUSION

Current PAH treatments improve clinically important outcomes, although the degree and certainty of benefit vary between treatments.

Involvement of endothelins in neuroprotection of valosin-containing protein modulators against retinal ganglion cell damage

We have previously shown that Kyoto University Substances (KUSs), valosin-containing protein (VCP) modulators, suppress cell death in retinal ganglion cells of glaucoma mouse models through alterations of various genes expressions. In this study, among the genes whose expression in retinal ganglion cells was altered by KUS treatment in the N-methyl-d-aspartic acid (NMDA) injury model, we focused on two genes, endothelin-1 (Edn1) and endothelin receptor type B (Ednrb), whose expression was up-regulated by NMDA and down-regulated by KUS treatment. First, we confirmed that the expression of Edn1 and Ednrb was upregulated by NMDA and suppressed by KUS administration in mice retinae. Next, to clarify the influence of KUSs on cell viability in relation to the endothelin signaling, cell viability was examined with or without antagonists or agonists of endothelin and with or without KUS in 661W retinal cells under stress conditions. KUS showed a significant protective effect under glucose-free conditions and tunicamycin-induced stress. This protective effect was partially attenuated in the presence of an endothelin antagonist or agonist under glucose-free conditions. These results suggest that KUSs protect cells partially by suppressing the upregulated endothelin signaling under stress conditions.

Selexipag-based triple combination therapy improves prognosis in Chinese pulmonary arterial hypertension patients

Aim

Selexipag is an oral selective prostacyclin receptor agonist approved for treatment of patients with pulmonary arterial hypertension (PAH). In the present study, we aim to assess the safety and efficacy of selexipag in triple combination therapy with endothelial receptor antagonists (ERAs) and PDE5is for Chinese PAH patients.

Methods and results

A single center retrospective study was performed on group 1 PAH patients (n = 68) initiating triple combination therapy with selexipag from 1 February 2020 to 31 August 2021 in Qilu Hospital of Shandong University (Shandong, China). Adolescents, children, and PAH patients with unrepaired congenital heart disease were excluded. The French pulmonary hypertension network (FPHN) non-invasive risk assessment, echocardiogram parameters, and clinical data, including tolerability, safety, and death/hospitalization events associated with PAH, were collected. Of the 68 patients, 31 (45.6%) patients had tolerable side effects while only a single patient discontinued selexipag due to severe diarrhea. In the analysis of the efficacy set of 62 patients, the median selexipag treatment time from selexipag initiation to last risk assessment was 27 (21, 33) weeks. Compared to baseline parameters, the percentage of WHO FC III/IV decreased from 77.4% (48) to 24.2% (15) (p = 0.000), median 6-min walk distance (6MWD) increased 82 m [from 398 (318, 450) to 480 (420, 506) m; p = 0.000], and NT-proBNP levels decreased from 1,216 (329, 2,159) to 455 (134, 1,678) pg/mL (p = 0.007). Patients who improved to three low-risk criteria increased from 9.7 to 38.7%. Right ventricular diameter (RV) diameter also decreased and was accompanied by an improved tricuspid annular plane systolic excursion (TAPSE). Patients transitioning from subcutaneous treprostinil to selexipag continued to show improvements in WHO FC, 6MWD (404 ± 94 vs. 383 ± 127 m) and NT-proBNP levels (2,319 ± 2,448 vs. 2,987 ± 3,770 pg/mL). Finally, the 1-year event free survival rate was 96.7% for patients initiating the triple combination therapy within 3 years of PAH diagnosis.

Conclusion

Triple combination therapy with selexipag was safe and effective in Chinese PAH patients, which was confirmed by acceptable tolerability, and improved exercise capacity, right heart function, risk assessment, and prognosis.

Pulmonary pressure recovery in idiopathic, hereditary and drug and toxin-induced pulmonary arterial hypertension: Determinants and clinical impact

BACKGROUND

Over the past two decades randomized controlled trials of combination treatments for Pulmonary Arterial Hypertension (PAH) have demonstrated improvements of clinical status but only modest reductions in mean pulmonary pressure (mPAP). Recent experiences with upfront combination treatments including parenteral prostacyclins have shown more substantial mPAP reductions, and have provided grounds for reconsiderations of treatment.

OBJECTIVES

To evaluate the possibility of achieving mPAP <25 mmHg with current treatments, its determinants and the prognostic impact of mPAP reduction.

METHODS

267 consecutive idiopathic, hereditary and drug and toxin-induced PAH patients treated with targeted therapies from three expert centers were followed with periodic clinical and hemodynamic assessments for survival detection.

RESULTS

Fifty-four (20.2%) patients achieved a mPAP <25 mmHg over 58 months (IQR 27-90) of treatment. Determinants of mPAP <25 mmHg were mPAP at diagnosis (HR 0.96, 95C.I. 0.93-0.98, p = 0.002) and an upfront combination strategy (double oral combination: HR 2.3, 95C.I. 1.10-4.76, p = 0.02; one oral plus parenteral prostanoid: HR 3.6, 95C.I. 1.39-9.37, p = 0.008; triple combination employing parenteral prostanoids: HR 12.9, 95C.I. 4.9-33.2, p = 0.0001). Seventy-three patients (27.3%) died. Survival rates were 90%, 79%, 70%, 55%, and 42% at 1, 3, 5, 10, and 15 years, respectively. Mean PAP during follow-up, days from diagnosis to prostanoid initiation and prostanoid maximum dose emerged as independent predictors of survival (Uno-C-index: 0.85). A mPAP ≤35 mmHg during follow-up was identified as the best cutoff value for prediction of survival.

CONCLUSIONS

Reduction to a mean PAP ≤ 35 mmHg appears to be a meaningful treatment target in idiopathic, hereditary and drug and toxin-induced pulmonary arterial hypertension.

Exploring the pivotal role of endothelin in rheumatoid arthritis

A chronic inflammatory disorder, rheumatoid arthritis (RA) is an autoimmune and systemic disease characterized by progressive and prolonged destruction of joints. This results in increased mortality, physical disability and destruction. Cardiovascular disorders are one of the primary causes of mortality in patients with RA. It is multifactorial in nature and includes genetic, environmental and demographic factors which contribute to the severity of disease. Endothelin-1 (ET-1) is a peptide which acts as a potent vasoconstrictor and is generated through vascular smooth muscle and endothelial cells. Endothelins may be responsible for RA, as under certain circumstances they produce reactive oxygen species which further promote the production of pro-inflammatory cytokines. This enhances the production of superoxide anion, which activates pro-inflammatory cytokines, resulting in RA. The aim of this review is to elucidate the role of endothelin in the progression of RA. This review also summarizes the natural and synthetic anti-inflammatory drugs which have provided remarkable insights in targeting endothelin.

KLF4 recruits SWI/SNF to increase chromatin accessibility and reprogram the endothelial enhancer landscape under laminar shear stress

Physiologic laminar shear stress (LSS) induces an endothelial gene expression profile that is vasculo-protective. In this report, we delineate how LSS mediates changes in the epigenetic landscape to promote this beneficial response. We show that under LSS, KLF4 interacts with the SWI/SNF nucleosome remodeling complex to increase accessibility at enhancer sites that promote the expression of homeostatic endothelial genes. By combining molecular and computational approaches we discover enhancers that loop to promoters of KLF4- and LSS-responsive genes that stabilize endothelial cells and suppress inflammation, such as BMPR2, SMAD5, and DUSP5. By linking enhancers to genes that they regulate under physiologic LSS, our work establishes a foundation for interpreting how non-coding DNA variants in these regions might disrupt protective gene expression to influence vascular disease.

Effects of oral anticoagulant therapy in patients with pulmonary diseases

Background

To evaluate the effect of oral anticoagulants (OACs) therapy, including vitamin K antagonist (VKA) and direct oral anticoagulants (DOAC) in patients with pulmonary diseases.

Methods

Literature from PubMed, MEDLINE, and Cochrane Library were screened until June 2022. Studies assessing OACs for pulmonary hypertension (PH), pulmonary embolism (PE), pulmonary fibrosis (PF), or chronic obstructive pulmonary disease (COPD) were evaluated for inclusion.

Results

Our study indicated that in patients with PH, PE, and COPD, OACs could significantly reduce the mortality risk, and the effects of VKA and DOACs without statistical difference in reducing the risk of recurrent embolism events. In patients with sclerosis-associated pulmonary arterial hypertension (SSc-PAH) or idiopathic pulmonary fibrosis (IPF), vitamin K antagonist (warfarin) significantly increased the mortality risk, while DOACs were not. As for the safety outcome of OACs, existing studies indicate that compared with patients treated with warfarin, the users of DOAC have a lower risk of major bleeding, while there is no statistical significance between them in non-major bleeding events. In current guidelines, the anticoagulation regimen for patients with pulmonary disease has not been defined. The results of our study confirm that DOACs (apixaban, rivaroxaban, dabigatran, and edoxaban) are superior to VKAs in the efficacy and safety outcomes of patients with pulmonary disease.

Conclusions

Oral anticoagulant therapy brings benefits to patients with PH, PE, or COPD, while the anticoagulation regimen for patients with SSc-PAH or IPF requires serious consideration. Compared with VKA, DOAC is a non-inferior option for anticoagulation in pulmonary disease treatment. Further studies are still needed to provide more reliable evidence about the safety outcome of pulmonary disease anticoagulation.

Effects of oral targeted treatments in pulmonary arterial hypertension: A systematic review and meta-analysis

Background

Although pulmonary arterial hypertension (PAH) is a fatal disease, specific drugs have been used to treat PAH. These drugs predominantly target these three pathobiological pathways: Endothelin receptor antagonist (ERA), nitric oxide (NO), and prostanoids pathways. In this review, we aimed to analyze the efficacy and safety of oral targeted treatments for PAH.

Methods

The national library of medicine (MEDLINE), excerpta medica database (EMBASE), and Cochrane Central Register of Controlled Trials databases were searched. Randomized controlled trials that compared the oral targeted drugs with placebos were selected. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) for variables with dichotomous outcomes, and standardized mean differences with continuous outcomes variables. Additionally, the mean of the differences for the 6-min walk distance (6MWD) was analyzed.

Results

In total, 23 studies involving 7,121 patients were included in this study. These studies show that orally PAH-specific drugs could decrease the risk of clinical worsening events, with an OR of 0.55 (p < 0.001). Furthermore, these drugs could improve exercise capacity, showing a 21.74-m increase in 6MWD (95% CI: 17.53–25.95 m) and cause a greater amelioration of functional class (OR = 0.60, 95% CI: 0.47–0.76). Additionally, subgroup analysis indicated that compared with placebo, ERAs, and drugs in the NO pathway were most effective and safe, which are associated with an improvement in exercise capacity, 6MWD, and worsening events-free survival rate.

Conclusion

Nitric oxide exhibited the most prominent clinical effect on exercise tolerance. However, in the subgroup analysis, oral targeted drugs of different pathways show applicability to different populations, which highlights the need for precise treatment in the clinical setting.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=297946], identifier [CRD 42022297946].

An Overview of Circulating Pulmonary Arterial Hypertension Biomarkers

Pulmonary arterial hypertension (PAH), also known as Group 1 Pulmonary Hypertension (PH), is a PH subset characterized by pulmonary vascular remodeling and pulmonary arterial obstruction. PAH has an estimated incidence of 15-50 people per million in the United States and Europe, and is associated with high mortality and morbidity, with patients' survival time after diagnosis being only 2.8 years. According to current guidelines, right heart catheterization is the gold standard for diagnostic and prognostic evaluation of PAH patients. However, this technique is highly invasive, so it is not used in routine clinical practice or patient follow-up. Thereby, it is essential to find new non-invasive strategies for evaluating disease progression. Biomarkers can be an effective solution for determining PAH patient prognosis and response to therapy, and aiding in diagnostic efforts, so long as their detection is non-invasive, easy, and objective. This review aims to clarify and describe some of the potential new candidates as circulating biomarkers of PAH.

Dynamics of 6-Minute Walk Distance as a Predictor of Efficiency Specific Pulmonary Vasodilators

Pulmonary hypertension is a severe and often rapidly progressive disease with a fatal outcome. Approved specific therapy with five classes of drugs – prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, soluble guanylate cyclase stimulators and prostacyclin receptor agonists has significantly improved the prognosis of patients. An accessible and reproducible criterion of exercise tolerance – a distance walked in six-minute walk test (6MXD) – occupies one of the central places among the performance indicators (clinical, echocardiographic and hemodynamic) of specific pulmonary vasodilators. Reflecting the clinical severity of pulmonary hypertension and, according to some data, its long-term prognosis, the dynamics of 6MXD is an integral component of the combined primary endpoints of randomized controlled trials. In the CHEST-2019 recommendations, the dynamics of the 6MXD was used to standardize the randomized controlled trials. The 6MXD is indispensable for dynamic observation and decisionmaking on further treatment tactics 

Nonsurgical treatment of cerebral ischemia associated with ACTA2 cerebral arteriopathy: a case report and literature review

Mutations in ACTA2 gene can lead to multisystemic smooth muscle dysfunction, including cerebrovascular disease. Treatment strategies for this rare entity remain controversial, and patients are at increasing risk of neurological sequelae. We herein present the case of an 11-year-old boy previously diagnosed with an ACTA2 gene mutation who developed repetitive transient ischemic attacks and treated with bosentan, an oral endothelin receptor antagonist. Magnetic resonance imaging revealed bilateral, periventricular white matter T2 hyperintensities, and magnetic resonance angiography identified several abnormalities including fusiform dilatation in the proximal segments of internal cerebral arteries, together with followed by terminal segmental stenosis. The distal branches showed a markedly straightened course with no increase in lenticulostriate collaterals. Magnetic resonance imaging also revealed an increase in the number and size of large periventricular white matter lesions located in the left frontal lobe with the progression of ischemic symptoms. Instead of revascularization surgery, the administration of bosentan was started due to the high risk of perioperative ischemic sequelae. After bosentan initiation, the patient's repetitive episodes of cerebral ischemia ceased, and there has been no increase in the number of white matter lesions for 7 years. Bosentan might be beneficial for treating cerebral ischemia associated with ACTA2 cerebral arteriopathy by maintaining the dilatation of stenotic vessels and adequate systemic blood flow and should be considered before performing revascularization surgery.

A Semi-Automated Term Harmonization Pipeline Applied to Pulmonary Arterial Hypertension Clinical Trials

OBJECTIVE

Data harmonization is essential to integrate individual participant data from multiple sites, time periods, and trials for meta-analysis. The process of mapping terms and phrases to an ontology is complicated by typographic errors, abbreviations, truncation, and plurality. We sought to harmonize medical history (MH) and adverse events (AE) term records across 21 randomized clinical trials in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

METHODS

We developed and applied a semi-automated harmonization pipeline for use with domain-expert annotators to resolve ambiguous term mappings using exact and fuzzy matching. We summarized MH and AE term mapping success, including map quality measures, and imputation of a generalizing term hierarchy as defined by the applied Medical Dictionary for Regulatory Activities (MedDRA) ontology standard.

RESULTS

Over 99.6% of both MH (N = 37,105) and AE (N = 58,170) records were successfully mapped to MedDRA low-level terms. Automated exact matching accounted for 74.9% of MH and 85.5% of AE mappings. Term recommendations from fuzzy matching in the pipeline facilitated annotator mapping of the remaining 24.9% of MH and 13.8% of AE records. Imputation of the generalized MedDRA term hierarchy was unambiguous in 85.2% of high-level terms, 99.4% of high-level group terms, and 99.5% of system organ class in MH, and 75% of high-level terms, 98.3% of high-level group terms, and 98.4% of system organ class in AE.

CONCLUSION

This pipeline dramatically reduced the burden of manual annotation for MH and AE term harmonization and could be adapted to other data integration efforts.

Diagnosis and Treatment of Pulmonary Arterial Hypertension: A Review

IMPORTANCE

Pulmonary arterial hypertension (PAH) is a subtype of pulmonary hypertension (PH), characterized by pulmonary arterial remodeling. The prevalence of PAH is approximately 10.6 cases per 1 million adults in the US. Untreated, PAH progresses to right heart failure and death.

OBSERVATIONS

Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 20 mm Hg and is classified into 5 clinical groups based on etiology, pathophysiology, and treatment. Pulmonary arterial hypertension is 1 of the 5 groups of PH and is hemodynamically defined by right heart catheterization demonstrating a mean pulmonary artery pressure greater than 20 mm Hg, a pulmonary artery wedge pressure of 15 mm Hg or lower, and a pulmonary vascular resistance of 3 Wood units or greater. Pulmonary arterial hypertension is further divided into subgroups based on underlying etiology, consisting of idiopathic PAH, heritable PAH, drug- and toxin-associated PAH, pulmonary veno-occlusive disease, PAH in long-term responders to calcium channel blockers, and persistent PH of the newborn, as well as PAH associated with other medical conditions including connective tissue disease, HIV, and congenital heart disease. Early presenting symptoms are nonspecific and typically consist of dyspnea on exertion and fatigue. Currently approved therapy for PAH consists of drugs that enhance the nitric oxide-cyclic guanosine monophosphate biological pathway (sildenafil, tadalafil, or riociguat), prostacyclin pathway agonists (epoprostenol or treprostinil), and endothelin pathway antagonists (bosentan and ambrisentan). With these PAH-specific therapies, 5-year survival has improved from 34% in 1991 to more than 60% in 2015. Current treatment consists of combination drug therapy that targets more than 1 biological pathway, such as the nitric oxide-cyclic guanosine monophosphate and endothelin pathways (eg, ambrisentan and tadalafil), and has shown demonstrable improvement in morbidity and mortality compared with the previous conventional single-pathway targeted monotherapy.

CONCLUSIONS AND RELEVANCE

Pulmonary arterial hypertension affects an estimated 10.6 per 1 million adults in the US and, without treatment, typically progresses to right heart failure and death. First-line therapy with drug combinations that target multiple biological pathways are associated with improved survival.

Aprocitentan and the endothelin system in resistant hypertension

Endothelin has emerged as a target for therapeutic intervention in systemic hypertension. As a vasoconstrictor, co-mitogenic agent, linking pulse pressure and vascular remodeling, and mediator of aldosterone and catecholamine release, endothelin is a key player in hypertension and end-organ damage. In 10-20% of the hypertensive population, the high blood pressure is resistant to administration of antihypertensive drugs of different classes in combination. Because endothelin is not targeted by the current antihypertensive drugs this may suggest that this resistance is due, in part at least, to a dependence on endothelin. This hypothesis is supported by the observation that this form of hypertension is often salt-sensitive, and that the endothelin system is stimulated by salt. In addition, the endothelin system is activated in subjects at risk of developing resistant hypertension, such as African-Americans or patients with obesity or obstructive sleep apnea. Aprocitentan is a novel, potent, dual endothelin receptor antagonist (ERA) currently in phase 3 development for the treatment of difficult-to-treat hypertension. This article discusses the research which underpinned the discovery of this ERA and the choice of its first clinical indication for patients with forms of hypertension which cannot be well controlled with classical antihypertensive drugs.

The Design of Multi-target Drugs to Treat Cardiovascular Diseases: Two (or more) Birds on one Stone

Cardiovascular diseases (CVDs) comprise a group of diseases and disorders of the heart and blood vessels, which together are the number one cause of death worldwide, being associated with multiple genetic and modifiable risk factors, and that may directly arise from different etiologies. For a long time, the search for cardiovascular drugs was based on the old paradigm "one compound - one target", which aims to obtain a highly potent and selective molecule with only one desired molecular target. Although historically successful in the last decades, this approach ignores the multiple causes and the multifactorial nature of CVD's. Thus, over time, treatment strategies for cardiovascular diseases have changed and, currently, pharmacological therapies for CVD are mainly based on the association of two or more drugs to control symptoms and reduce cardiovascular death. In this context, the development of multitarget drugs, i.e, compounds having the ability to act simultaneously at multiple sites, is an attractive and relevant strategy that can be even more advantageous to achieve predictable pharmacokinetic and pharmacodynamics correlations as well as better patient compliance. In this review, we aim to highlight the efforts and rational pharmacological bases for the design of some promising multitargeted compounds to treat important cardiovascular diseases like heart failure, atherosclerosis, acute myocardial infarction, pulmonary arterial hypertension and arrhythmia.

Old and new therapeutic strategies in systemic sclerosis (Review)

Systemic sclerosis (SSc) is a chronic inflammatory disease with autoimmune determinism having an incompletely known pathogenesis. Although not all links in the pathogenic chain are known, studies have shown that vasculopathy is the initial event and is followed by extensive fibrosis of the skin and internal organs. New therapeutic strategies have been developed in recent years, thanks to innovative research which has increased understanding of the disease mechanisms. No curative treatment for SSc is currently known. Therefore, the therapeutic target in SSc is its symptomatology. Peripheral vasculopathy can be improved by administering vasodilators. Endothelin receptor antagonists and 5-phosphodiesterase inhibitors have a double benefit, both on peripheral and on pulmonary vasculopathy. Several molecules with antifibrotic effects are currently available; however, further studies are needed to confirm their beneficial effects. Immunosuppressants manage to control the cutaneous and visceral fibrotic process, thereby remaining as first-line drugs in the treatment of SSc. Although biological therapy using rituximab and tocilizumab has shown promising results in pulmonary fibrosis, ongoing studies are needed to determine their exact impact. The authors have differing views on the triggering role of glucocorticoids and the benefits of angiotensin-converting enzyme inhibitors in renal scleroderma. Some aspects of this disease such as calcinosis and pruritus, asthenia, or joint and muscle damage, remain difficult to manage.

Update on Medical Management of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a rare disease characterized by pulmonary microvasculature remodeling leading to right ventricular failure and death. Medical management of pulmonary hypertension has grown increasingly complex as more therapeutic agents have been developed. Evolving treatment strategies leveraging the endothelin, nitric oxide, and prostacyclin pathways lead to improved exercise capacity and outcomes in patients; however, significant opportunities for advancement remain.

The prognostic significance of the alterations of pulmonary hemodynamics in patients with pulmonary arterial hypertension: a meta-regression analysis of randomized controlled trials

BACKGROUND

Hemodynamic assessment in patients with pulmonary arterial hypertension (PAH) is essential for risk stratification and pharmacological management. However, the prognostic value of the hemodynamic changes after treatment is less well established.

OBJECTIVES

We investigated the prognostic impacts of the changes in hemodynamic indices, including mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), right atrial pressure (RAP), and cardiac output index (CI). We conducted this systematic review with meta-regression analysis on existing clinical trials.

METHODS

We searched and identified all relevant randomized controlled trials from multiple databases. An analogous R² index was used to quantify the proportion of variance explained by each predictor in the association with PAH patients' prognosis. A total of 21 trials and 3306 individuals were enrolled.

RESULTS

The changes in mPAP, PVR, RAP, and CI were all significantly associated with the change in 6MWD (∆6MWD). The change in mPAP was with the highest explanatory power for ∆6MWD (R² analog = 0.740). Additionally, the changes in mPAP, PVR, and CI were independently predictive of adverse clinical events. The change in mPAP had the highest explanatory power for the clinical events (R² analog = 0.911). Furthermore, the change in PVR was with the highest explanatory power for total mortality of PAH patients (R² analog = 0.612).

CONCLUSION

Hemodynamic changes after treatment, including mPAP, PVR, CI, and RAP, were significantly associated with adverse clinical events or mortality in treated PAH patients. It is recommended that further studies be conducted to evaluate the changes in hemodynamic indices to guide drug titration.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019125157.

Trends in Systemic Sclerosis Mortality Over Forty-Eight Years, 1968-2015: A US Population-Based Study

OBJECTIVE

To identify secular trends associated with systemic sclerosis (SSc) mortality over a 48-year period.

METHODS

Using national mortality data compiled by the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research, and population data from the US Census Bureau, we calculated an age-standardized mortality rate (ASMR) for SSc and non-SSc (all other causes), and we also calculated the ratio of the SSc ASMR to the non-SSc ASMR for each year from 1968 to 2015. We then used a joinpoint regression model to evaluate mortality trends overall and by sex and race.

RESULTS

From 1968 to 2015, there were 46,798 deaths with SSc recorded as the "underlying" cause of death and 106,058,839 non-SSc deaths. There were an additional 9,063 deaths with SSc recorded as a "contributing" cause of death from 1999 to 2015. Whereas the non-SSc ASMR decreased throughout the 48-year time period, the SSc ASMR increased from 1968 to 2000, followed by decreases each year from 2001 to 2015. The SSc ASMR also decreased for deaths where SSc was a contributing cause from 1999 to 2015. Women and Black persons had higher SSc ASMRs and SSc ASMR to non-SSc ASMR ratios than men and White persons, respectively. Additionally, SSc ASMRs and SSc ASMR to non-SSc ASMR ratios increased at higher rates in women and White persons than in men and Black persons, respectively, during the initial three decades.

CONCLUSION

Mortality attributable to SSc increased from 1968 to 2000, followed by a steady decline from 2001 to 2015. However, SSc mortality relative to non-SSc mortality remains high. SSc mortality has disproportionately changed by sex and race over the 48-year period assessed in the present study.