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Predisposing factors for the development of a pre-capillary component in pulmonary hypertension associated with left heart disease remain elusive. We report the case of a patient with persistent combined post-capillary and pre-capillary pulmonary hypertension after cardiac transplantation, in whom a rare BMPR2 variant was found.

In the context of pulmonary arterial hypertension (PAH), echocardiographic assessment of right ventricular (RV) function is key to determining disease severity and prognosis. Using Doppler echocardiography (ECHO) there are numerous ways that RV function can be measured, either directly or indirectly, to capture the triad of changes in RV geometry, right-to-left interaction, and RV systolic dysfunction in response to high pulmonary vascular resistance states, such as PAH. To fully evaluate and characterize the nature and extent of the impact of PAH on the RV in an individual patient, it is critical to assess a combination of these direct and indirect measures of RV function. In order to predict changes in status and have prognostic significance, the variables used must be easy to measure, reproducible, and clinically relevant. This review assesses the relative value of different ECHO parameters and looks at what the future holds for ECHO imaging of the right heart in PAH. [ABSTRACT FROM AUTHOR]

Background: Invasive exercise right heart catheterization is a gold standard in diagnosing heart failure with preserved ejection fraction (HFpEF). Body positions during the test influence hemodynamics. However, the discrepancy in HFpEF diagnosis between exercise testing in supine versus upright position is unknown., Methods: We conducted a 2-center prospective study enrolling patients referred for exercise right heart catheterization for HFpEF. We performed a Supright protocol integrating submaximal supine bicycle ergometry (20 W) followed by maximal upright bicycle ergometry with a breath-by-breath oxygen analyzer. HFpEF hemodynamic criteria specific to testing positions were applied. Patients were considered to have concordant HFpEF if they met criteria in both positions or discordant HFpEF if they met criteria only in the supine position., Results: Of 36 patients who met HFpEF criteria in supine position, 18 (50%) did not meet criteria in upright position (discordant HFpEF). Discordant HFpEF had less atrial fibrillation (0% versus 55%; P <0.001), lower left atrial volume (60±14 versus 77±21 mL; P =0.010), and lower H 2 FPEF score (2.1±1.3 versus 5.1±2.3; P <0.001). In supine position, pulmonary arterial wedge pressure was lower in discordant HFpEF at rest (15±4 versus 19±7 mm Hg; P =0.040). In upright position, pulmonary arterial wedge pressure was lower in discordant HFpEF both at rest (8±4 versus 14±6 mm Hg; P =0.002) and at peak exercise (14±4 versus 27±7 mm Hg; P <0.001). Pulmonary arterial wedge pressure/cardiac output slope was lower in discordant HFpEF (1.6±1.7 versus 3.6±2.9; P <0.001). Maximal workload (46±18 versus 49±24 W; P =0.59) or peak oxygen consumption (11.4±2.8 versus 12.9±3.4 mL/[kg·min]; P =0.15) was similar between groups., Conclusions: Half of patients who met HFpEF criteria in the supine position did not meet the criteria in the upright position. Patients with a discordant HFpEF phenotype had less structural and hemodynamic abnormalities compared with those with concordant HFpEF. A Supright exercise right heart catheterization approach is feasible and merits further investigation to determine the clinical implications of discordant exercise hemodynamic findings in supine and upright positions.

Left heart disease (LHD) is the most common cause of pulmonary hypertension (PH), which may be classified further as isolated post-capillary (ipcPH) or combined post- and pre-capillary PH (cpcPH). The 7th World Symposium on Pulmonary Hypertension PH-LHD task force reviewed newly reported randomised clinical trials and contemplated novel opportunities for improving outcome. Results from major randomised clinical trials reinforced prior recommendations against the use of pulmonary arterial hypertension therapy in PH-LHD outside of clinical trials, and suggested possible harm. Greater focus on phenotyping was viewed as one general strategy by which to ultimately improve clinical outcomes. This is potentially achievable by individualising ipcPH versus cpcPH diagnosis for patients with pulmonary arterial wedge pressure within a diagnostic grey zone (12-18 mmHg), and through a newly developed PH-LHD staging system. In this model, PH accompanies LHD across four stages (A=at risk, B=structural heart disease, C=symptomatic heart disease, D=advanced), with each stage characterised by progression in clinical characteristics, haemodynamics and potential therapeutic strategies. Along these lines, the task force proposed disaggregating PH-LHD to emphasise specific subtypes for which PH prevalence, pathophysiology and treatment are unique. This includes re-interpreting mitral and aortic valve stenosis through a contemporary lens, and focusing on PH within the hypertrophic cardiomyopathy and amyloid cardiomyopathy clinical spectra. Furthermore, appreciating LHD in the profile of PH patients with chronic lung disease and chronic thromboembolic pulmonary disease is essential. However, engaging LHD patients in clinical research more broadly is likely to require novel methodologies such as pragmatic trials and may benefit from next-generation analytics to interpret results., Competing Interests: Conflict of interest: B.A. Maron reports grants from NIH/NHLBI and Deerfield Company, consultancy fees from Actelion and Tenax Therapeutics, and the following unlicensed patents: PCT/US2019/059890, #9,605,047 and PCT/US2020/066886. G. Bortman reports payment or honoraria for lectures, presentations, manuscript writing or educational events from Bago, Tuteur, Raffo, Aerovate, Novartis, United, Biosidus, Sandoz, Glaxo, Gador and MKD, support for attending meetings from Tuteur, Bago, Biosidus, Raffo, Sandoz, Boehringer, Gador, Glaxo and MKD, participation on a data safety monitoring board or advisory board with Aerovate and MKD, and is a member of the Argentina Heart Society, Argentina Transplant Society and LHL. T. De Marco reports grants from CareDx and Acceleron Pharm, consultancy fees from Aerovate, Boston Scientific, Atara, Kamada, Kerios, Merck, Natera, Pulnovo, Tectonic and United Therapeutics, payment or honoraria for lectures, presentations, manuscript writing or educational events from Simply Speaking PAH CME lecture, support for attending meetings from CareDx, Atara, Kamada and United Therapeutics, and participation on a data safety monitoring board or advisory board with Merck, Keros Therapeutics, Tectonic and BIAL. J.H. Huston has no potential conflicts of interest to disclose. I.M. Lang reports grants from AOP-Health, consultancy fees from Pulnovo, Janssen, MSD, Novo Norrdisk, Daiichi and Amarin, payment or honoraria for lectures, presentations, manuscript writing or educational events from MSD, Sanofi, Janssen and Daiichi, and support for attending meetings from Medtronic. S.H. Rosenkranz reports grants from Actelion, AstraZeneca, Bayer, Janssen, Lempo and MSD, consultancy fees from Abbott, Acceleron, Actelion, Aerovate, Altavant, AOP, AstraZeneca, Bayer, Ferrer, Gossamer, Janssen, Liquidia, MSD and UT, support for attending meetings from Bayer, participation on a data safety monitoring board or advisory board with Acceleron, Actelion, Aerovate, Altavant, AOP, Gossamer, Janssen, Liquidia, MSD and UT, and was ESC task force chair for the 2022 ESC/ERS guidelines on pulmonary hypertension. J-L. Vachiery reports consultancy fees from Merck, payment or honoraria for lectures, presentations, manuscript writing or educational events from Janssen, Merck, Boehringer Ingelheim and Novartis, support for attending meetings from Merck, participation on a data safety monitoring board or advisory board with Moderna, and has leadership roles with ISHLT and ESC. R.J. Tedford reports consultancy fees from Abbott, Acorai, Aria CV Inc., Acceleron/Merck, Alleviant, Boston Scientific, Cytokinetics, Edwards LifeSciences, Endotronix, Gradient, Medtronic, Morphic Therapeutics, Restore Medical and United Therapeutics, support for attending meetings from Abiomed, participation on a data safety monitoring board or advisory board with Restore Medical, stock (or stock options) with Aria CV, and is deputy editor for JHLT, and co-chair of the PH-LHD task force for WSPH., (Copyright ©The authors 2024.)

Pulmonary arterial hypertension (PAH) is a rare disease affecting the small pulmonary vessels, ultimately leading to right ventricular failure and death. Current treatment options target three different pathways (endothelin, nitric oxide/cGMP and prostacyclin pathways). Despite their demonstrated efficacy, these therapies (commonly used in combination) do not cure the disease which is why novel pathways beyond the traditional 'big three' are being developed. Sotatercept is a ligand trap for multiple proteins within the TGF-β superfamily that was recently approved in the US for the treatment of PAH. Unlike currently available therapies, sotatercept has the potential to act as an anti-remodelling agent rather than a vasodilator. The safety and efficacy of subcutaneous (SC) sotatercept have been established in two multicentre, placebo-controlled randomised-controlled trials. The compound has been shown to consistently improve a variety of measurable endpoints, including exercise capacity, haemodynamics, quality of life and delay of clinical worsening. The drug appears to have an acceptable safety profile, although it is associated with an increased risk in developing telangiectasia and biological changes affecting platelet counts and haemoglobin. This study reviews the current evidence on SC sotatercept and provides a Belgian perspective on its place in the future treatment strategy for PAH.

Background: Morbidity and mortality in pulmonary arterial hypertension (PAH) remain high. Activation of platelet-derived growth factor receptor, colony stimulating factor 1 receptor, and mast or stem cell growth factor receptor kinases stimulates inflammatory, proliferative, and fibrotic pathways driving pulmonary vascular remodelling in PAH. Seralutinib, an inhaled kinase inhibitor, targets these pathways. We aimed to evaluate the efficacy and safety of seralutinib in patients with PAH receiving standard background therapy., Methods: The TORREY trial was a phase 2, randomised, multicentre, multinational, double-blind, placebo-controlled study. Patients with PAH from 40 hospital and community sites were randomly assigned 1:1 via interactive response technologies to receive seralutinib (60 mg twice daily for 2 weeks, then increased to 90 mg twice daily as tolerated) or placebo by dry powder inhaler twice daily for 24 weeks. Randomisation was stratified by baseline pulmonary vascular resistance (PVR; <800 dyne·s/cm 5 and ≥800 dyne·s/cm 5 ). Patients were eligible if classified as WHO Group 1 PH (PAH), WHO Functional Class II or III, with a PVR of 400 dyne·s/cm 5 or more, and a 6 min walk distance of between 150 m and 550 m. The primary endpoint was change in PVR from baseline to 24 weeks. Analyses for efficacy endpoints were conducted in randomly assigned patients (intention-to-treat population). Safety analyses included all patients who received the study drug. TORREY was registered with ClinicalTrials.gov (NCT04456998) and EudraCT (2019-002669-37) and is completed., Findings: From Nov 12, 2020, to April 20, 2022, 151 patients were screened for eligibility, and following exclusions, 86 adults receiving PAH background therapy were randomly assigned to seralutinib (n=44; four male, 40 female) or placebo (n=42; four male, 38 female), and comprised the intention-to-treat population. At baseline, treatment groups were balanced except for a higher representation of WHO Functional Class II patients in the seralutinib group. The least squares mean change from baseline to week 24 in PVR was 21·2 dyne·s/cm 5 (95% CI -37·4 to 79·8) for the placebo group and -74·9 dyne·s/cm 5 (-139·7 to -10·2) for the seralutinib group. The least squares mean difference between the seralutinib and placebo groups for change in PVR was -96·1 dyne·s/cm 5 (95% CI -183·5 to -8·8; p=0·03). The most common treatment-emergent adverse event in both treatment groups was cough: 16 (38%) of 42 patients in the placebo group; 19 (43%) of 44 patients in the seralutinib group., Interpretation: Treatment with inhaled seralutinib significantly decreased PVR, meeting the primary endpoint of the study among patients receiving background therapy for PAH., Funding: Gossamer Bio., Competing Interests: Declaration of interests ARH reports having received consulting fees from United Therapeutics, Tenax Therapeutics, Merck, and Janssen; having served as an advisory committee member for Gossamer Bio; and having held stock from Tenax Therapeutics. CT, DM, EE, EP, J-MB, LSZ, MC, RA, RFR, and RO report stocks or stock options from Gossamer Bio; and employment at Gossamer Bio. LSZ also reported patents related to seralutinib (assigned to Gossamer Bio or Pulmokine); stocks or stock options from Pulmokine. RFR also reported previous consulting fees from Gossamer Bio. H-AG reports having received consulting fees from Gossamer Bio, Aerovate, Altavant, Bayer AG, Attgeno, Janssen and Actelion, MSD and Acceleron, and Pfizer; payment or honoraria for lectures, presentations, speaker bureaus, or educational events from Bayer AG, Janssen and Actelion, and MSD and Acceleron; participated as an advisory committee member for Aerovate, Altavant, Bayer AG, Attgeno, Janssen and Actelion, MSD and Acceleron, and Pfizer; and as a member of a data and safety monitoring board for Insmed. J-LV reports having received consulting fees from Gossamer Bio, ShouTi, Janssen, Enzyvant, Bayer HealthCare, Merck, Liquidia, Aerami, and Insmed; received payment or honoraria (payment to their institution) for lectures, presentations, or educational events from Janssen, Merck, Novartis, and Boehringer Ingelheim; received payment for expert testimony from Actelion Pharmaceuticals; received either support for attending meetings or travel (payment to their institution) from Merck; participated on a data safety monitoring board (payment to their institution) from Janssen, GSK, and Moderna; membership on steering committees for Gossamer Bio, Insmed, Merck, and United Therapeutics. KMC reports having received grants or contracts (payment made to their institution) for clinical studies overseen by her from Gossamer Bio, Janssen, United Therapeutics, Merck, Acceleron, and Altavant; received consulting fees from Acceleron; received fees for participating on an advisory board for Merck; received fees for work as an advisory committee member for Gossamer Bio; received fees for work as a steering committee member for Janssen; received fees for work on an adjudication committee for Arena and United Therapeutics; and received fees for an editorial role with the American Heart Association. LSH reported having received payment or honoraria for speaker bureau membership from Janssen; participated as an advisory board member for Janssen, MSD, Altavant, and United Therapeutics, and as an advisory committee member for Gossamer Bio; and having stock or stock options at ATXA Therapeutics, iOWNA, and Circular. OS reports having received grants or contracts for research (payment made to their institution) from Janssen, MSD, and AOP Orphan; payment or honoraria for lectures or an educational event from AOP Orphan, Ferrer, Janssen, and MSD; support for attending meetings or travel from MSD and Janssen; and participated on an advisory committee for Gossamer Bio, AOP Orphan, Enzyvant, Ferrer, Janssen, and MSD. PES reports having received payment or honoraria for lectures, presentations, speaker bureaus, manuscript writing, or educational events from Janssen, MSD, Ferrer, and AOT; support for either attending meetings or travel from Janssen and MSD; participated in a data safety monitoring board or advisory board for Janssen, MSD, Ferrer, Gossamer Bio, and AOT; and receipt of equipment, materials, drugs, medical writing, gifts, or other services from Gossamer Bio. RLB reports having received consulting fees from Merck, United Therapeutics, KEROS, Aerovate, Insmed, and Cereno; served as an advisory committee member for Gossamer Bio; served as an advisory board member for Altavant, Merck, Janssen, and Insmed; served on a data safety monitoring board for Janssen; and served on a scientific advisory board for Cereno. RLZ reports having received consulting fees from Johnson & Johnson, United Therapeutics, Bayer, and Alnylam. RNC reports having received consulting fees from Gossamer Bio, Janssen, Bayer, United Therapeutics, and Third Pole; payment or honoraria for lectures from Janssen and Bayer; and participated on an advisory committee for Gossamer Bio, Janssen, and Bayer. RPF reports having royalties or licenses from UpToDate; receiving consulting fees from Janssen and Liquidia; participated on a data safety monitoring board or advisory board from Gossamer Bio (as an advisory committee member); participated on an advisory board for Janssen, Liquidia, Tenax Therapeutics, ShouTi, Insmed, and Merck; and participated on a data safety monitoring board for Aerovate. RTZ reports having received grants or contracts for industry-supported research from United Therapeutics, Janssen, Tenax Therapeutics, and Gossamer Bio; consulting fees from Janssen, Vivus, Morphogen-IX, Merck, and Gossamer Bio; and stock or stock options from Selten. SS reports having received a research grant from United Therapeutics; speaker honoraria (received by his institute) from Janssen and United Therapeutics; served as an advisor to Janssen, Bayer, United Therapeutics, Gossamer Bio, Altavant Sciences, and Merck; served as a steering committee member for Bayer, Keros, and Liquidia Technologies; and served as a data safety monitoring board committee member for the National Institutes of Health K23 grant. VVM reports having received grant support from Aerovate, Enzyvant, Gossamer Bio, Janssen, Merck, and Sonovie; consulting fees from Aerami, Aerovate, Caremark, Corvista, Enzyvant, Gossamer Bio, Janssen, Merck, United Therapeutics, and Vertex; and participated as an advisory committee member for Gossamer Bio. All authors report receiving medical writing and editorial support for the present manuscript funded by Gossamer Bio., (Copyright © 2024 Elsevier Ltd. 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Background: Pulmonary hypertension and right ventricular (RV) dysfunction are major prognostic determinants in patients with heart failure with preserved ejection fraction (HFpEF). The underlying pathomechanisms remain unknown. In this context, we sought to study the pathogenesis of pulmonary hypertension and RV dysfunction in a rat model of obesity-associated HFpEF., Methods and Results: HFpEF was induced in obesity-prone rats fed a high-fat diet (n=13) and compared with obesity-resistant rats fed with standard chow (n=9). After 12 months, the animals underwent echocardiographic and hemodynamic evaluation followed by tissue sampling for pathobiological assessment. HFpEF rats presented mild RV pressure overload (with increased RV systolic pressure and pulmonary vascular resistance). No changes in pulmonary artery medial thickness and ex vivo vasoreactivity (to acetylcholine and endothelin-1) were observed and RNA sequencing analysis failed to identify gene clustering in HFpEF lungs. However, released nitric oxide levels were decreased in HFpEF pulmonary artery, while lung expression of preproendothelin-1 was increased. In HFpEF rats, RV structure and function were altered, with RV enlargement, decreased RV fractional area change and free wall longitudinal fractional shortening, together with altered right ventricle-pulmonary artery coupling (estimated by tricuspid annular plane systolic excursion/systolic pulmonary artery pressure). Hypertrophy and apoptosis (evaluated by transferase biotin- dUTP nick-end labeling staining) were increased in right and left ventricles of HFpEF rats. There was an inverse correlation between tricuspid annular plane systolic excursion/systolic pulmonary artery pressure and RV apoptotic rate. Plasma levels of soluble suppression of tumorigenicity-2, interleukin-1β, -6 and -17A were increased in HFpEF rats., Conclusions: Obesity-associated HFpEF in rats spontaneously evolves to pulmonary hypertension-HFpEF associated with impaired right ventricle-pulmonary artery coupling that appears disproportionate to a slight increase in RV afterload.

Pulmonary hypertension (PH) is a common complication of diseases affecting the left heart, mostly found in patients suffering from heart failure, with or without preserved left ventricular ejection fraction. Initially driven by a passive increase in left atrial pressure (postcapillary PH), several mechanisms may lead in a subset of patient to significant structural changes of the pulmonary vessels or a precapillary component. In addition, the right ventricle may be independently affected, which results in right ventricular to pulmonary artery uncoupling and right ventricular failure, all being associated with a worse outcome. The differential diagnosis of PH associated with left heart disease versus pulmonary arterial hypertension (PAH) is especially challenging in patients with cardiovascular comorbidities and/or heart failure with preserved ejection fraction (HFpEF). A stepwise approach to diagnosis is proposed, starting with a proper clinical multidimensional phenotyping to identify patients in whom hemodynamic confirmation is deemed necessary. Provocative testing (exercise testing, fluid loading, or simple leg raising) is useful in the cath laboratory to identify patients with abnormal response who are more likely to suffer from HFpEF. In contrast with group 1 PH, management of PH associated with left heart disease must focus on the treatment of the underlying condition. Some PAH-approved targets have been unsuccessfully tried in clinical studies in a heterogeneous group of patients, some even leading to an increase in adverse events. There is currently no approved therapy for PH associated with left heart disease., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Among patients with heart failure with preserved ejection fraction (HFpEF), a distinct hemodynamic phenotype has been recently described, ie, latent pulmonary vascular disease (HFpEF-latentPVD), defined by exercise pulmonary vascular resistance (PVR) >1.74 WU., Objectives: This study aims to explore the pathophysiological significance of HFpEF-latentPVD., Methods: The authors analyzed a cohort of patients who had undergone supine exercise right heart catheterization with cardiac output (CO) measured by direct Fick method, between 2016 and 2021. HFpEF-latentPVD patients were compared with HFpEF control patients., Results: Out of 86 HFpEF patients, 21% qualified as having HFpEF-latentPVD, 78% of whom had PVR >2 WU at rest. Patients with HFpEF-latentPVD were older, with a higher pretest probability of HFpEF, and more frequently experienced atrial fibrillation and at least moderate tricuspid regurgitation (P < 0.05). PVR trajectories differed between HFpEF-latentPVD patients and HFpEF control patients (P interaction  = 0.008), slightly increasing in the former and reducing in the latter. HFpEF-latentPVD patients displayed more frequent hemodynamically significant tricuspid regurgitation during exercise (P = 0.002) and had more impaired CO and stroke volume reserve (P < 0.05). Exercise PVR was correlated with mixed venous O 2 tension (R 2  = 0.33) and stroke volume (R 2  = 0.31) in HFpEF-latentPVD patients. The HFpEF-latentPVD patients had had higher dead space ventilation during exercise and higher PaCO 2 (P < 0.05), which correlated with resting PVR (R 2  = 0.21). Event-free survival was reduced in HFpEF-latentPVD patients (P < 0.05)., Conclusions: The results suggest that when CO is measured by direct Fick, few HFpEF patients have isolated latent PVD (ie, normal PVR at rest, becoming abnormal during exercise). HFpEF-latentPVD patients present with CO limitation to exercise, associated with dynamic tricuspid regurgitation, altered ventilatory control, and pulmonary vascular hyperreactivity, portending a poor prognosis., Competing Interests: Funding Support and Author Disclosures This study was funded by the Italian Ministry of Health 5 x 1000. Dr Baratto is the recipient of a research grant from the European Society of Cardiology. Dr Vachiéry is the holder of the Actelion Research Chair on Pulmonary Hypertension in his department. Dr Fudim was supported by the National Heart, Lung, and Blood Institute (K23HL151744), the American Heart Association (20IPA35310955), Doris Duke, Bayer, Bodyport, and Verily; and has been the recipient of consulting fees from Abbott, Alio Health, Alleviant, Audicor, AxonTherapies, Bayer, Bodyguide, Bodyport, Boston Scientific, Cadence, Coridea, CVRx, Daxor, Deerfield Catalyst, Edwards LifeSciences, EKO, Feldschuh Foundation, Fire1, Gradient, Impulse Dynamics, Intershunt, Medtronic, NIMedical, NXT Biomedical, Pharmacosmos, PreHealth, ReCor, Shifamed, Splendo, Sumacor, SyMap, Verily, Vironix, Viscardia, and Zoll. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary artery wedge pressure (PAWP) during exercise, as a surrogate for left ventricular (LV) end-diastolic pressure (EDP), is used to diagnose heart failure with preserved ejection fraction (HFpEF). However, LVEDP is the gold standard to assess LV filling, end-diastolic PAWP (PAWP ED ) is supposed to coincide with LVEDP and mean PAWP throughout the cardiac cycle (PAWP M ) better reflects the haemodynamic load imposed on the pulmonary circulation. The objective of the present study was to determine precision and accuracy of PAWP estimates for LVEDP during exercise, as well as the rate of agreement between these measures., Methods: 46 individuals underwent simultaneous right and left heart catheterisation, at rest and during exercise, to confirm/exclude HFpEF. We evaluated: linear regression between LVEDP and PAWP, Bland-Altman graphs, and the rate of concordance of dichotomised LVEDP and PAWP ≥ or < diagnostic thresholds for HFpEF., Results: At peak exercise, PAWP M and LVEDP, as well as PAWP ED and LVEDP, were fairly correlated (R 2 >0.69, p<0.01), with minimal bias (+2 and 0 mmHg respectively) but large limits of agreement (±11 mmHg). 89% of individuals had concordant PAWP and LVEDP ≥ or <25 mmHg (Cohen's κ=0.64). Individuals with either LVEDP or PAWP M ≥25 mmHg showed a PAWP M increase relative to cardiac output (CO) changes (PAWP M /CO slope) >2 mmHg·L -1 ·min -1 ., Conclusions: During exercise, PAWP is accurate but not precise for the estimation of LVEDP. Despite a good rate of concordance, these two measures might occasionally disagree., Competing Interests: Conflict of interest: None declared., (Copyright ©The authors 2023.)

Background: Right heart failure (RHF) is associated with a dismal prognosis in patients with pulmonary hypertension (PH). Exercise right heart catheterization may unmask right heart maladaptation as a sign of RHF. We sought to (1) define the normal limits of right atrial pressure (RAP) increase during exercise; (2) describe the right heart adaptation to exercise in PH owing to heart failure with preserved ejection fraction (PH-HFpEF) and in pulmonary arterial hypertension (PAH); and (3) identify the factors associated with right heart maladaptation during exercise., Methods and Results: We analyzed rest and exercise right heart catheterization from patients with PH-HFpEF and PAH. Right heart adaptation was described by absolute or cardiac output (CO)-normalized changes of RAP during exercise. Individuals with noncardiac dyspnea (NCD) served to define abnormal RAP responses (>97.5th percentile). Thirty patients with PH-HFpEF, 30 patients with PAH, and 21 patients with NCD were included. PH-HFpEF were older than PAH, with more cardiovascular comorbidities, and a higher prevalence of severe tricuspid regurgitation (P < .05). The upper limit of normal for peak RAP and RAP/CO slope in NCD were >12 mm Hg and ≥1.30 mm Hg/L/min, respectively. PH-HFpEF had higher peak RAP and RAP/CO slope than PAH (20 mm Hg [16-24 mm Hg] vs 12 mm Hg [9-19 mm Hg] and 3.47 mm Hg/L/min [2.02-6.19 mm Hg/L/min] vs 1.90 mm Hg/L/min [1.01-4.29 mm Hg/L/min], P < .05). A higher proportion of PH-HFpEF had RAP/CO slope and peak RAP above normal (P < .001). Estimated stressed blood volume at peak exercise was higher in PH-HFpEF than PAH (P < .05). In the whole PH cohort, the RAP/CO slope was associated with age, the rate of increase in estimated stressed blood volume during exercise, severe tricuspid regurgitation, and right atrial dilation., Conclusions: Patients with PH-HFpEF display a steeper increase of RAP during exercise than those with PAH. Preload-mediated mechanisms may play a role in the development of exercise-induced RHF., Competing Interests: Declaration of Competing Interest None, (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aims: The HFA-PEFF algorithm (Heart Failure Association-Pre-test assessment, Echocardiography and natriuretic peptide score, Functional testing in cases of uncertainty, Final aetiology) is a three-step algorithm to diagnose heart failure with preserved ejection fraction (HFpEF). It provides a three-level likelihood of HFpEF: low (score < 2), intermediate (score 2-4), or high (score > 4). HFpEF may be confirmed in individuals with a score > 4 (rule-in approach). The second step of the algorithm is based on echocardiographic features and natriuretic peptide levels. The third step implements diastolic stress echocardiography (DSE) for controversial diagnostic cases. We sought to validate the three-step HFA-PEFF algorithm against a haemodynamic diagnosis of HFpEF based on rest and exercise right heart catheterization (RHC)., Methods and Results: Seventy-three individuals with exertional dyspnoea underwent a full diagnostic work-up following the HFA-PEFF algorithm, including DSE and rest/exercise RHC. The association between the HFA-PEFF score and a haemodynamic diagnosis of HFpEF, as well as the diagnostic performance of the HFA-PEFF algorithm vs. RHC, was assessed. The diagnostic performance of left atrial (LA) strain < 24.5% and LA strain/E/E' < 3% was also assessed. The probability of HFpEF was low/intermediate/high in 8%/52%/40% of individuals at the second step of the HFA-PEFF algorithm and 8%/49%/43% at the third step. After RHC, 89% of patients were diagnosed as HFpEF and 11% as non-cardiac dyspnoea. The HFA-PEFF score resulted associated with the invasive haemodynamic diagnosis of HFpEF (P < 0.001). Sensitivity and specificity of the HFA-PEFF score for the invasive haemodynamic diagnosis of HFpEF were 45% and 100% for the second step of the algorithm and 46% and 88% for the third step of the algorithm. Neither age, sex, body mass index, obesity, chronic obstructive pulmonary disease, or paroxysmal atrial fibrillation influenced the performance of the HFA-PEFF algorithm, as these characteristics were similarly distributed over the true positive, true negative, false positive, and false negative cases. Sensitivity of the second step of the HFA-PEFF score was non-significantly improved to 60% (P = 0.08) by lowering the rule-in threshold to >3. LA strain alone had a sensitivity and specificity of 39% and 14% for haemodynamic HFpEF, increasing to 55% and 22% when corrected for E/E'., Conclusions: As compared with rest/exercise RHC, the HFA-PEFF score lacks sensitivity: Half of the patients were wrongly classified as non-cardiac dyspnoea after non-invasive tests, with a minimal impact of DSE in modifying HFpEF likelihood., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Aims: Diffusing capacity of the lung for carbon monoxide (DL CO ) reduction is common in heart failure (HF) and is associated with a worse prognosis. Correlations between DL CO and pulmonary hypertension (PH) are unclear, and published data are conflicting; it has been shown that DL CO impairment may persist or even worsen after normalization of pulmonary pressures following left ventricle assist device (LVAD) implantation, maybe reflecting persistent pulmonary damage. We aimed to investigate the impact of pre-implant DL CO and central haemodynamics on outcome in patients with advanced HF implanted with a LVAD., Methods and Results: We retrospectively analysed pre-implant and post-implant data from 42 patients implanted with a LVAD at our institution. Out of 42 patients, 35 had post-capillary PH before implantation, including 17 with combined post- and pre-capillary PH (Cpc-PH). Median DL CO was 59% (IQR 47-68%), and it inversely correlated with pulmonary vascular resistance (PVR) (P 0.037) and diastolic pulmonary gradient (DPG) (P 0.042). Compared with baseline, LVAD resulted in improvement in LV diameter (LVDd, P < 0.001), mitral regurgitation (P 0.022), and PH (mPAP 24 vs. 36 mmHg, P < 0.001; PAWP 12 vs. 23 mmHg, P 0.001; pulmonary artery compliance, C PA 3.1 vs. 1.9 mL/mmHg, P 0.021). Lower DL CO and Cpc-PH at baseline were associated with a better LV reverse remodelling post-implantation (P 0.027 for LVDd) but also with a smaller gain in C PA (P 0.049)., Conclusions: Before LVAD implantation, DL CO impairment is associated with higher PVR and DPG, suggesting that it might be an expression of persistent pulmonary damage occurring in Cpc-PH. After LVAD implantation, both LV dimension and haemodynamics improve. Lower pre-implant DL CO is associated with better LV reverse remodelling., (© 2022 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background: Both secondary tricuspid regurgitation (STR) and heart failure with preserved ejection fraction (HFpEF) are relevant public health problems in the elderly population, presenting with potential overlaps and sharing similar risk factors. However, the impact of severe STR on hemodynamics and cardiorespiratory adaptation to exercise in HFpEF remains to be clarified., Aim: To explore the impact of STR on exercise hemodynamics and cardiorespiratory adaptation in HFpEF., Methods: We analyzed invasive hemodynamics and gas-exchange data obtained at rest and during exercise from HFpEF patients with severe STR (HFpEF-STR), compared with 1:1 age-, sex-, and body mass index (BMI)- matched HFpEF patients with mild or no STR (HFpEF-controls)., Results: Twelve HFpEF with atrial-STR (mean age 72 years, 92% females, BMI 28 Kg/m 2 ) and 12 HFpEF-controls patients were analyzed. HFpEF-STR had higher ( p < 0.01) right atrial pressure than HFpEF-controls both at rest (10 ± 1 vs. 5 ± 1 mmHg) and during exercise (23 ± 2 vs. 14 ± 2 mmHg). Despite higher pulmonary artery wedge pressure (PAWP) at rest in HFpEF-STR than in HFpEF-controls (17 ± 2 vs. 11 ± 2, p = 0.04), PAWP at peak exercise was no more different (28 ± 2 vs. 29 ± 2). Left ventricular transmural pressure and cardiac output (CO) increased less in HFpEF-STR than in HFpEF-controls (interaction p -value < 0.05). This latter was due to lower stroke volume (SV) values both at rest (48 ± 9 vs. 77 ± 9 mL, p < 0.05) and at peak exercise (54 ± 10 vs. 93 ± 10 mL, p < 0.05). Despite these differences, the two groups of patients laid on the same oxygen consumption isophlets because of the increased peripheral oxygen extraction in HFpEF-STR ( p < 0.01). We found an inverse relationship between pulmonary vascular resistance and SV, both at rest and at peak exercise ( R 2 = 0.12 and 0.19, respectively)., Conclusions: Severe STR complicating HFpEF impairs SV and CO reserve, leading to pulmonary vascular de-recruitment and relative left heart underfilling, undermining the typical HFpEF pathophysiology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer GI declared a shared parent affiliation with the authors CB, SC, GC, DS, AZ, MG, FH, MT, NR, FP, GPe, GPa, LB, and DM to the handling editor at the time of the review., (Copyright © 2023 Baratto, Caravita, Corbetta, Soranna, Zambon, Dewachter, Gavazzoni, Heilbron, Tomaselli, Radu, Perelli, Perego, Vachiéry, Parati, Badano and Muraru.)

Background: Right Heart Failure (RHF) is a severe complication that can occur after left ventricular assist device (LVAD) implantation, increasing early and late mortality. Although numerous RHF predictive scores have been developed, limited data exist on the external validation of these models. We therefore aimed at comparing existent risk score models and identifying predictors of severe RHF at our center., Methods: In this retrospective, single-center analysis, clinical, biological and functional data were collected in patients implanted with a LVAD between 2011 and 2020. Early severe RHF was defined as the use of inotropes for ≥ 14 days, nitric oxide use for ≥ 48 h or unplanned right-sided circulatory support. Risk models were evaluated for the primary outcome of RHF or RVAD implantation by means of logistic regression and receiver operating characteristic curves., Results: Among 92 patients implanted, 24 (26%) developed early severe RHF. The EUROMACS-RHF risk score performed the best in predicting RHF (C = 0.82-95% CI: 0.68-0.90), compared with the other scores (Michigan, CRITT). In addition, we developed a new model, based on four variables selected for the best reduced logistic model: the INTERMACS level, the number of inotropes used, the ratio of right atrial/pulmonary capillary wedge pressure and the ratio of right ventricle/left ventricle diameters by echocardiography. This model demonstrated significant discrimination of RHF (C = 0.9-95% CI: 0.76-0.96)., Conclusion: Amongst available risk scores, EUROMACS-RHF performs best to predict the occurrence of RHF after LVAD implantation. Our model's performance compares well to the EUROMACS-RHF score, adding a more objective parameter to RV function evaluation., (© 2022. The Japanese Society for Artificial Organs.)

Pulmonary hypertension (PH) is associated with a poor prognosis in left heart disease (LHD). We sought to provide an updated analysis on the association of hemodynamic variables, such as pulmonary vascular resistance (PVR), pulmonary artery compliance (PAC), and diastolic pressure gradient (DPG), with prognosis in PH-LHD, through a systematic literature review. Sixteen articles were identified, including 9600 patients with LHD, heterogeneous in terms of age, sex, and etiology of cardiac disease. In this large population, PVR (hazard ratio [HR], 1.07; 95% confidence interval [CI]: 1.05-1.0), DPG (HR, 1.02; 95% CI: 1.01-1.02) and PAC (HR, 0.76; 95% CI: 0.69-0.84) were associated with an increased risk of adverse outcome, albeit with a less solid performance of DPG. Similar results were found when hemodynamic variables were analyzed according to the thresholds commonly applied in clinical practice, or subdividing cohorts according to the underlying LHD. Furthermore, cumulative metanalysis indicated that these results are consistently stable since 2018. Thus, PVR, DPG and PAC have an established prognostic value in PH-LHD. These results are consistent through the years and unlikely to change with further studies., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Aims: Exercise right heart catheterization (RHC) is considered the gold-standard test to diagnose heart failure with preserved ejection fraction (HFpEF). However, exercise RHC is an insufficiently standardized technique, and current haemodynamic thresholds to define HFpEF are not universally accepted. We sought to describe the exercise haemodynamics profile of HFpEF cohorts reported in literature, as compared with control subjects., Methods and Results: We performed a systematic literature review until December 2020. Studies reporting pulmonary artery wedge pressure (PAWP) at rest and peak exercise were extracted. Summary estimates of all haemodynamic variables were evaluated, stratified according to body position (supine/upright exercise). The PAWP/cardiac output (CO) slope during exercise was extrapolated. Twenty-seven studies were identified, providing data for 2180 HFpEF patients and 682 controls. At peak exercise, patients with HFpEF achieved higher PAWP (30 [29-31] vs. 16 [15-17] mmHg, P < 0.001) and mean right atrial pressure (P < 0.001) than controls. These differences persisted after adjustment for age, sex, body mass index, and body position. However, peak PAWP values were highly heterogeneous among the cohorts (I 2  = 93%), with a relative overlap with controls. PAWP/CO slope was steeper in HFpEF than in controls (3.75 [3.20-4.28] vs. 0.95 [0.30-1.59] mmHg/L/min, P value < 0.0001), even after adjustment for covariates (P = 0.007)., Conclusions: Despite methodological heterogeneity, as well as heterogeneity of pooled haemodynamic estimates, the exercise haemodynamic profile of HFpEF patients is consistent across studies and characterized by a steep PAWP rise during exercise. More standardization of exercise haemodynamics may be advisable for a wider application in clinical practice., (© 2022 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

The outbreak of novel coronavirus-19 disease (COVID-19) was classified as a global pandemic thanks to the rapid viral spread, and restrictive policy measures of infection containment, including "lockdown" periods and self-isolation, were first instituted in Belgium from March to June 2020. The consequent reduction in physical activity could have a negative impact on exercise capacity, especially in frail patients with pre-existing chronic diseases, such as pulmonary arterial hypertension (PAH). With the aim to define the impact of COVID-19 lockdown on functional status, we included in our observational analysis clinically stable PAH patients, who had performed at least four consecutive 6-min walking tests (6MWT) during 2019-2020, to compare their exercise performance before and after the lockdown. In the 63 patients included, a comparison between the distance covered at 6MWT after the lockdown period and the pooled mean of the previous three 6MWTs showed a mean reduction of 14 m after the lockdown ( p  = 0.004). Moreover, the mean distance covered at 6MWT went from 447 m in March 2020 to 434 m in June 2020, with a significant average loss of 13 m ( p  = 0.024). Our results showed that PAH patients were less performing at 6MWT after 3 months of reduced physical activity, despite constant clinical stability and the absence of signs of disease progression, suggesting that this confounding factor should be kept in mind when evaluating changes in 6MWT during or after COVID-19 pandemic., Competing Interests: The need for written informed consent was waived due to the retrospective nature of the study., (© 2022 The Authors. Pulmonary Circulation published by Wiley Periodicals LLC on behalf of the Pulmonary Vascular Research Institute.)

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure and frequently is associated with pulmonary hypertension (PH). HFpEF associated with PH may be difficult to distinguish from precapillary forms of PH, although this distinction is crucial because therapeutic pathways are divergent for the two conditions. A comprehensive and systematic approach using history, clinical examination, and noninvasive and invasive evaluation with and without provocative testing may be necessary for accurate diagnosis and phenotyping. After diagnosis, HFpEF associated with PH can be subdivided into isolated postcapillary pulmonary hypertension (IpcPH) and combined postcapillary and precapillary pulmonary hypertension (CpcPH) based on the presence or absence of elevated pulmonary vascular resistance. CpcPH portends a worse prognosis than IpcPH. Despite its association with reduced functional capacity and quality of life, heart failure hospitalizations, and higher mortality, therapeutic options focused on PH for HFpEF associated with PH remain limited. In this review, we aim to provide an updated overview on clinical definitions and hemodynamically characterized phenotypes of PH, pathophysiologic features, therapeutic strategies, and ongoing challenges in this patient population., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Aims: Pulmonary hypertension (PH) is a common complication of left heart disease (LHD, Group 2 PH) leading to right ventricular (RV) failure and death. Several loss-of-function (LOF) mutations in KCNK3 were identified in pulmonary arterial hypertension (PAH, Group 1 PH). Additionally, we found that KCNK3 dysfunction is a hallmark of PAH at pulmonary vascular and RV levels. However, the role of KCNK3 in the pathobiology of PH due to LHD is unknown., Methods and Results: We evaluated the role of KCNK3 on PH induced by ascending aortic constriction (AAC), in WT and Kcnk3-LOF-mutated rats, by echocardiography, RV catheterization, histology analyses, and molecular biology experiments. We found that Kcnk3-LOF-mutation had no consequence on the development of left ventricular (LV) compensated concentric hypertrophy in AAC, while left atrial emptying fraction was impaired in AAC-Kcnk3-mutated rats. AAC-animals (WT and Kcnk3-mutated rats) developed PH secondary to AAC and Kcnk3-mutated rats developed more severe PH than WT. AAC-Kcnk3-mutated rats developed RV and LV fibrosis in association with an increase of Col1a1 mRNA in right ventricle and left ventricle. AAC-Kcnk3-mutated rats developed severe pulmonary vascular (pulmonary artery as well as pulmonary veins) remodelling with intense peri-vascular and peri-bronchial inflammation, perivascular oedema, alveolar wall thickening, and exaggerated lung vascular cell proliferation compared to AAC-WT-rats. Finally, in lung, right ventricle, left ventricle, and left atrium of AAC-Kcnk3-mutated rats, we found a strong increased expression of Il-6 and periostin expression and a reduction of lung Ctnnd1 mRNA (coding for p120 catenin), contributing to the exaggerated pulmonary and heart remodelling and pulmonary vascular oedema in AAC-Kcnk3-mutated rats., Conclusions: Our results indicate that Kcnk3-LOF is a key event in the pathobiology of PH due to AAC, suggesting that Kcnk3 channel dysfunction could play a potential key role in the development of PH due to LHD., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Pulmonary hypertension due to left heart diseases (PH-LHD) is the most prevalent form of pulmonary hypertension. It frequently complicates heart failure with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF) and negatively impacts prognosis, particularly when a precapillary component is present. PH-LHD is distinctive from pulmonary arterial hypertension (PAH) even though both conditions may share some common characteristics. In addition, the mechanisms involved in the development of a precapillary component are yet to be fully clarified, in particular in PH due to HFpEF. Several studies have been exploring PAH pathways as potential therapies for PH-LHD, but no PAH-approved drug has demonstrated efficacy in PH-LHD. Rather, some classes of drugs, such as endothelin-receptor antagonists or prostacycline-analogues, have been found to be harmful in patients with HF. Therefore, at present, the only established treatments for PH-LHD are those that target the heart as recommended in the international guidelines for HF. Based on current knowledge, off-label prescription of PAH-approved drugs in PH-LHD patients must be strongly discouraged., (Copyright: © 2021 The Author(s).)

Background: Exercise hemodynamics can differentiate heart failure with preserved ejection fraction (HFpEF) from noncardiac dyspnea. However, respiratory pressure swings may impact hemodynamic measurements, potentially leading to misdiagnosis of HFpEF. Moreover, threshold values for abnormal hemodynamic response indicative of HFpEF are not universally accepted. Thus, we sought to evaluate the impact of respiratory pressure swings on hemodynamic data interpretation as well as the concordance among 3 proposed exercise hemodynamic criteria for HFpEF: (1) end-expiratory pulmonary artery wedge pressure (PAWP exp ) ≥25 mm Hg; (2) PAWP exp /cardiac output slope >2 mm Hg/L per minute; and (3) respiratory-averaged (avg) mean pulmonary artery pressure >30 mm Hg, total pulmonary resistance avg >3 WU, PAWP avg ≥20 mm Hg., Methods: Fifty-seven patients with unexplained dyspnea (70% women, 70±9 years) underwent exercise cardiac catheterization. The difference between end-expiratory and averaged hemodynamic values, as well as the concordance among the 3 hemodynamic definitions of HFpEF, were assessed., Results: End-expiratory hemodynamics measurements were higher than values averaged across the respiratory cycle. During exercise, a larger proportion of patients exceeded the threshold of 25 mm Hg for PAWP exp rather than for PAWP avg (70% versus 53%, P <0.01). The concordance of 3/3 HFpEF exercise hemodynamic criteria was recorded in 70% of patients. PAWP exp /cardiac output slope identified HFpEF more frequently than the other 2 criteria (81% versus 64% to 69%), incorporating over 97% of abnormal responses to the latter. Patients with 3/3 positive criteria had worse clinical, gas-exchange, and hemodynamic profiles., Conclusions: Respiratory pressure swings impact on the exercise hemodynamic definitions of HFpEF that provide discordant results in 30% of patients. Equivocal diagnoses of HFpEF might be limited by adopting the most sensitive and inclusive criterion alone (ie, PAWP exp /cardiac output slope).

Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase 3 randomized trials. The EXPosurE Registry RiociguaT in patients with pulmonary hypertension (EXPERT) study was designed to monitor the long-term safety of riociguat in clinical practice., Methods: EXPERT was an international, multicenter, prospective, uncontrolled, non-interventional cohort study of patients treated with riociguat. Patients were followed for at least 1 year and up to 4 years from enrollment or until 30 days after stopping riociguat treatment. Primary safety outcomes were adverse events (AEs) and serious adverse events (SAEs) coded using Medical Dictionary for Regulatory Activities preferred terms and System Organ Classes version 21.0, collected during routine clinic visits and collated via case report forms., Results: In total, 956 patients with CTEPH were included in the analysis. The most common AEs in these patients were peripheral edema/edema (11.7%), dizziness (7.5%), right ventricular (RV)/cardiac failure (7.7%), and pneumonia (5.0%). The most common SAEs were RV/cardiac failure (7.4%), pneumonia (4.1%), dyspnea (3.6%), and syncope (2.5%). Exposure-adjusted rates of hemoptysis/pulmonary hemorrhage and hypotension were low and comparable to those in the long-term extension study of riociguat (Chronic Thromboembolic Pulmonary Hypertension Soluble Guanylate Cyclase-Stimulator Trial [CHEST-2])., Conclusion: Data from EXPERT show that in patients with CTEPH, the safety of riociguat in routine practice was consistent with the known safety profile of the drug, and no new safety concerns were identified., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension following Phase 3 randomized trials. The EXPosurE Registry RiociguaT in patients with pulmonary hypertension (EXPERT) study was designed to monitor the long-term safety of riociguat in clinical practice., Methods: EXPERT was an international, multicenter, prospective, uncontrolled, non-interventional cohort study of patients treated with riociguat. Patients were followed for at least 1 year and up to 4 years from enrollment or until 30 days after stopping riociguat treatment. Primary safety outcomes were adverse events (AEs) and serious adverse events (SAEs) coded using Medical Dictionary for Regulatory Activities preferred terms and System Organ Classes version 21.0, collected during routine clinic visits (usually every 3-6 months) and collated via case report forms., Results: In total, 326 patients with PAH were included in the analysis. The most common AEs in these patients were dizziness (11.7%), right ventricular (RV)/cardiac failure (10.7%), edema/peripheral edema (10.7%), diarrhea (8.6%), dyspnea (8.0%), and cough (7.7%). The most common SAEs were RV/cardiac failure (10.1%), pneumonia (6.1%), dyspnea (4.0%), and syncope (3.4%). The exposure-adjusted rate of hemoptysis/pulmonary hemorrhage was 2.5 events per 100 patient-years., Conclusion: Final data from EXPERT show that in patients with PAH, the safety of riociguat in clinical practice was consistent with clinical trials, with no new safety concerns identified and a lower exposure-adjusted rate of hemoptysis/pulmonary hemorrhage than in the long-term extension of the Phase 3 trial in PAH., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

This international survey highlights that a limited number of PAH and CTEPH patients suffered from severe #COVID19 infection https://bit.ly/3jGuBQq., Competing Interests: Conflict of interest: C. Belge reports personal fees from Actelion/Janssen and MSD/Bayer outside the submitted work. Conflict of interest: R. Quarck has nothing to disclose. Conflict of interest: L. Godinas reports personal fees from Actelion outside the submitted work. Conflict of interest: D. Montani reports grants and personal fees from Actelion and Bayer, personal fees from GSK and Pfizer, grants, personal fees and nonfinancial support from MSD, personal fees from Chiesi and Boerhinger, and nonfinancial support from Acceleron, outside the submitted work. Conflict of interest: P. Escribano Subias reports personal fees and grants from Janssen, and personal fees from MSD, GlaxoSmithKline and Ferrer, outside the submitted work. Conflict of interest: J-L. Vachiery reports grants from Actelion J&J, and other support from Bayer HealthCare, Bial Portela, PhaseBio, Respira Therapeutics and United Therapeutics, outside the submitted work. Conflict of interest: H. Nashat reports grants from Actelion Pharmaceuticals outside the submitted work. Conflict of interest: J. Pepke-Zaba reports grants, personal fees and nonfinancial support from Actelion, grants and personal fees from Merck, and personal fees from Bayer, outside the submitted work. Conflict of interest: M. Humbert reports grants and personal fees from Actelion, and personal fees from GSK, Merck and Acceleron, outside the submitted work. Conflict of interest: M. Delcroix reports grants and other support from Actelion/J&J, and other support from Bayer, MSD, Reata, Bellarophon and Acceleron, outside the submitted work., (Copyright ©ERS 2020.)

Objectives: To evaluate how pulmonary artery (PA) distensibility performs in detecting pulmonary hypertension due to left heart disease (PH-LHD) in comparison with parameters from ungated computed tomography (CT) and echocardiography., Methods: One hundred patients (79 men, mean age = 63 ± 17 years) with either severe heart failure with reduced ejection fraction (HFrEF), aortic stenosis, or primary mitral regurgitation prospectively underwent right heart catheterization, ungated CT, ECG-gated CT, and echocardiography. During the ECG-gated CT, the right PA distensibility was calculated. In ungated CT, dPA, dPA/AA, the ratio of dPA to the diameter of the vertebra, segmental PA diameter, segmental PA-to-bronchus ratio, and the main PA volume were measured; the egg-and-banana sign was recorded. During echocardiography, the tricuspid regurgitation (TR) gradient was measured. The areas under the ROC curves (AUC) of these signs were computed and compared with DeLong test. Correlation between PA distensibility and PA pressure (PAP) was investigated through Pearson's coefficient., Results: PA distensibility was lower in patients with PH than in those without PH (11.4 vs. 21.2%, p < 0.001) and correlated negatively with mean PAP (r = - 0.72, p < 0.001). Age, PA size, and mean PAP were independent predictors of PA distensibility. PA distensibility < 18% detected PH-LHD with 96% sensitivity and 73% specificity; its AUC was 0.92, larger than that of any other sign at ungated CT and TR gradient (AUC ranging from 0.54 to 0.83, DeLong: p ranging from 0.020 to < 0.001)., Conclusion: PA distensibility on an ECG-gated CT can detect PH-LHD better than the parameters reflecting PA dilatation in ungated CT or TR gradient in the echocardiography of patients with severe HFrEF, aortic stenosis, or mitral regurgitation., Key Points: • In left heart disease, pulmonary artery distensibility is lower in patients with PH than in those without pulmonary hypertension (11.4 vs. 21.2%, p < 0.001). • In left heart disease, pulmonary artery distensibility detects pulmonary hypertension with an area under the receiver operating curve of 0.92. • In left heart disease, the area under the receiver operating curve of pulmonary artery distensibility for detecting pulmonary hypertension is larger than that of all other signs at ungated CT (p from 0.019 to < 0.001) and tricuspid regurgitation gradient at echocardiography (p = 0.020).

Background: In the randomized, double-blind, event-driven AMBITION study, initial combination therapy with ambrisentan and tadalafil was associated with a 50% reduction in risk of clinical failure (first occurrence of all-cause death, hospitalization for worsening pulmonary arterial hypertension [PAH], disease progression, or unsatisfactory long-term clinical response) vs pooled monotherapy. These results were primarily driven by a reduction in PAH-related hospitalization in the combination therapy group, although a significant effect was not observed in a post-hoc analysis of all-cause hospitalization., Methods: The effect of initial combination therapy with ambrisentan and tadalafil in AMBITION was further explored to study PAH-related hospitalization, which was not reported in the primary publication., Results: Initial combination therapy was associated with a 63% reduction in risk of PAH-related hospitalization when compared with pooled monotherapy (hazard ratio [HR] 0.372, 95% confidence interval [CI] 0.217 to 0.639, p = 0.0002). For every 9 patients treated with combination therapy vs monotherapy, 1 PAH-related hospitalization could be prevented over a 1-year period. Serious adverse events leading to hospitalization, not necessarily PAH-related, occurred in 87 of 253 (34%) and 89 of 247 (36%) of patients on combination therapy and pooled monotherapy, respectively (post-hoc summary)., Conclusions: Initial combination therapy with ambrisentan and tadalafil was found to reduce the risk of PAH-related hospitalization by 63% compared with pooled monotherapy., (Copyright © 2018. Published by Elsevier Inc.)

Pulmonary hypertension (PH) is frequent in left heart disease (LHD), as a consequence of the underlying condition. Significant advances have occurred over the past 5 years since the 5th World Symposium on Pulmonary Hypertension in 2013, leading to a better understanding of PH-LHD, challenges and gaps in evidence. PH in heart failure with preserved ejection fraction represents the most complex situation, as it may be misdiagnosed with group 1 PH. Based on the latest evidence, we propose a new haemodynamic definition for PH due to LHD and a three-step pragmatic approach to differential diagnosis. This includes the identification of a specific "left heart" phenotype and a non-invasive probability of PH-LHD. Invasive confirmation of PH-LHD is based on the accurate measurement of pulmonary arterial wedge pressure and, in patients with high probability, provocative testing to clarify the diagnosis. Finally, recent clinical trials did not demonstrate a benefit in treating PH due to LHD with pulmonary arterial hypertension-approved therapies., Competing Interests: Conflict of interest: J-L. Vachiéry reports consultancy and speaker fees paid to institution, and is an investigator in clinical trials for Actelion Pharmaceuticals and Bayer, consultancy fees paid to institution from Novartis, and consultancy fees paid to institution, and is an investigator in clinical trials for Sonivie and Pfizer, during the conduct of the study; consultancy fees paid to institution, and is an investigator in clinical trials for Arena Pharmaceuticals, Bial Portela and Sonivie, consultancy and speaker fees paid to institution, and is an investigator in clinical trials for GSK and Pfizer, consultancy fees and travel grants paid to institution from MSD, and is an investigator in clinical trials for Reata, outside the submitted work. Conflict of interest: R.J. Tedford reports personal fees (Hemodynamic Core Lab) from Actelion, J&J and Merck, and personal fees for steering committee membership from Abbott, outside the submitted work. Conflict of interest: S. Rosenkranz reports personal fees for lectures and/or consultancy from Abbott, Actelion, Arena, Bayer, BMS, MSD, Novartis, Pfizer and United Therapeutics, and institutional research grants from Actelion, Bayer, Novartis, Pfizer and United Therapeutics, outside the submitted work; and serves as chair of the Working Group “Pulmonary circulation and right ventricular function” of the European Society of Cardiology. Conflict of interest: M. Palazzini has nothing to disclose. Conflict of interest: I. Lang reports grants and personal fees from Actelion and AOP Orphan Pharma, and personal fees from Sanofi and Novartis, outside the submitted work. Conflict of interest: M. Guazzi has nothing to disclose. Conflict of interest: G. Coghlan has nothing to disclose. Conflict of interest: I. Chazova has nothing to disclose. Conflict of interest: T. De Marco reports grants from Actelion Pharmaceuticals, Pfizer, United Therapeutics, Gilead, Boston Scientific, Bellerophon, Respirex, Arena Pharmaceutical and Novartis, outside the submitted work., (Copyright ©ERS 2019.)

Background: In pulmonary hypertension (PH), both wedge pressure elevation (PAWP) and a precapillary component may affect right ventricular (RV) afterload. These changes may contribute to RV failure and prognosis. We aimed at describing the different haemodynamic phenotypes of patients with PH due to left heart disease (LHD) and at characterizing the impact of pulmonary haemodynamics on RV function and outcome PH-LHD., Methods: Patients with PH-LHD were compared with treatment-naïve idiopathic/heritable pulmonary arterial hypertension (PAH, n = 35). PH-LHD patients were subdivided in Isolated post-capillary PH (IpcPH: diastolic pressure gradient, DPG<7 mmHg and pulmonary vascular resistance, PVR≤3 WU, n = 37), Combined post- and pre-capillary PH (CpcPH: DPG≥7 mmHg and PVR>3 WU, n = 27), and "intermediate" PH-LHD (either DPG <7 mmHg or PVR ≤3 WU, n = 29)., Results: Despite similar PAWP and cardiac index, haemodynamic severity and prevalence of RV dysfunction increased from IpcPH, to "intermediate" and CpcPH. PVR and DPG (but not compliance, Ca) were linearly correlated with RV dysfunction. CpcPH had worse prognosis (p<0.05) than IpcPH and PAH, but similar to "intermediate" patients. Only NTproBNP and Ca independently predicted survival in PH-LHD., Conclusions: In PH-LHD, haemodynamic characterization according to DPG and PVR provides important information on disease severity, predisposition to RV failure and prognosis. Patients presenting the CpcPH phenotype appear to have haemodynamic profile closer to PAH but with worse prognosis. In PH-LHD, Ca and NTproBNP were independent predictors of survival., Competing Interests: JLV is the holder of the Actelion Research Chair on Pulmonary Hypertension in his department. SC is the recipient of a ERS PAH Short-Term Research Training Fellowship (STRTF 2014-5264) supported by an unrestricted grant by GSK, and of the international grant “Cesare Bartorelli” for the year 2014 funded by the Italian Society of Hypertension. This does not alter our adherence to PLOS ONE policies on sharing data and materials. None of the other authors has a financial relationship with a commercial entity that has an interest in the subject of the present manuscript or other conflicts of interest to disclose.

Purpose: A proportion of patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) do not achieve treatment goals or experience side effects on their current therapy. In such cases, switching patients to a new drug while discontinuing the first may be a viable and appropriate treatment option. CAPTURE was designed to investigate how physicians manage the switching of patients to riociguat in real-world clinical practice. Observations from the study were used to assess whether recommendations in the riociguat prescribing information are reflected in clinical practice., Methods: CAPTURE was an international, multicenter, uncontrolled, retrospective chart review that collected data from patients with PAH or inoperable or persistent/recurrent CTEPH who switched to riociguat from another pulmonary hypertension (PH)-targeted medical therapy. The primary objective of the study was to understand the procedure undertaken in real-world clinical practice for patients switching to riociguat., Results: Of 127 patients screened, 125 were enrolled in CAPTURE. The majority of patients switched from a phosphodiesterase type 5 inhibitor (PDE5i) to riociguat and the most common reason for switching was lack of efficacy. Physicians were already using the recommended treatment-free period when switching patients to riociguat from sildenafil, but a slightly longer period than recommended for tadalafil. In line with the contraindication, the majority of patients did not receive riociguat and PDE5i therapy concomitantly. Physicians also followed the recommended dose-adjustment procedure for riociguat., Conclusion: Switching to riociguat from another PH-targeted therapy may be feasible in real-world clinical practice in the context of the current recommendations.

The original version of this article unfortunately contained a mistake. In the "Results" section, the percentage of patients with inoperable or persistent/recurrent CTEPH included in the study was reported as 85%. This has been corrected to 68% with this erratum.

The MELODY-1 study evaluated macitentan for pulmonary hypertension because of left heart disease (PH-LHD) in patients with combined post- and pre-capillary PH.63 patients with PH-LHD and diastolic pressure gradient ≥7 mmHg and pulmonary vascular resistance (PVR) >3WU were randomised to macitentan 10 mg (n=31) or placebo (n=32) for 12 weeks. The main end-point assessed a composite of significant fluid retention (weight gain ≥5% or ≥5 kg because of fluid overload or parenteral diuretic administration) or worsening in New York Heart Association functional class from baseline to end of treatment. Exploratory end-points included changes in N-terminal pro-brain natriuretic peptide (NT-proBNP) and haemodynamics at week 12.Seven macitentan-treated and four placebo-treated patients experienced significant fluid retention/worsening functional class; treatment difference, 10.08% (95% CI -15.07-33.26; p=0.34). The difference, driven by the fluid retention component, was apparent within the first month. At week 12, versus placebo, the macitentan group showed no change in PVR, mean right atrial pressure or pulmonary arterial wedge pressure; a non-significant increase in cardiac index (treatment effect 0.4 (95% CI 0.1-0.7) L·min -1 ·m -2 ) and decrease in NT-proBNP (0.77 (0.55-1.08)) was observed. Adverse events and serious adverse events were numerically more frequent with macitentan versus placebo.Macitentan-treated patients were quantitatively more likely to experience significant fluid retention versus placebo. Macitentan resulted in no significant changes in any exploratory end-points., Competing Interests: Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com, (Copyright ©ERS 2018.)

Background: Following positive results from the Phase III CHEST-1 study in patients with inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH), the Phase IIIb CTEPH early access study (EAS) was designed to assess the safety and tolerability of riociguat in real-world clinical practice, as well as to provide patients with early access to riociguat before launch. Riociguat is approved for the treatment of inoperable and persistent/recurrent CTEPH., Methods: We performed an open-label, uncontrolled, single-arm, early access study in which 300 adult patients with inoperable or persistent/recurrent CTEPH received riociguat adjusted from 1 mg three times daily (tid) to a maximum of 2.5 mg tid. Patients switching from unsatisfactory prior pulmonary arterial hypertension (PAH)-targeted therapy (n = 84) underwent a washout period of at least 3 days before initiating riociguat. The primary aim was to assess the safety and tolerability of riociguat, with World Health Organization functional class and 6-min walking distance (6MWD) as exploratory efficacy endpoints., Results: In total, 262 patients (87%) completed study treatment and entered the safety follow-up (median treatment duration 47 weeks). Adverse events were reported in 273 patients (91%). The most frequently reported serious adverse events were syncope (6%), right ventricular failure (3%), and pneumonia (2%). There were five deaths, none of which was considered related to study medication. The safety and tolerability of riociguat was similar in patients switched from other PAH-targeted therapies and those who were treatment naïve. In patients with data available, mean ± standard deviation 6MWD had increased by 33 ± 42 m at Week 12 with no clinically relevant differences between the switched and treatment-naïve subgroups., Conclusions: Riociguat was well tolerated in patients with CTEPH who were treatment naïve, and in those who were switched from other PAH-targeted therapies. No new safety signals were observed., Trial Registration: ClinicalTrials.org NCT01784562 . Registered February 4, 2013.

Background: Patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH), in particular systemic sclerosis (SSc), had an attenuated response compared with idiopathic PAH in most trials. Thus, there is uncertainty regarding the benefit of PAH-targeted therapy in some forms of CTD-PAH., Objective: To explore the safety and efficacy of initial combination therapy with ambrisentan and tadalafil versus ambrisentan or tadalafil monotherapy in patients with CTD-PAH and SSc-PAH enrolled in the AMBITION trial., Methods: This was a post hoc analysis of patients with CTD-PAH and SSc-PAH from AMBITION, an event-driven, double-blind trial in patients with WHO functional class II/III PAH. Treatment-naive patients were randomised 2:1:1 to once-daily initial combination therapy with ambrisentan plus tadalafil or monotherapy with ambrisentan or tadalafil, respectively. The primary endpoint was time to the first clinical failure event (first occurrence of death, hospitalisation for worsening PAH, disease progression or unsatisfactory long-term clinical response)., Results: In the primary analysis set (N=500), 187 patients had CTD-PAH, of whom 118 had SSc-PAH. Initial combination therapy reduced the risk of clinical failure versus pooled monotherapy in each subgroup: CTD-PAH (HR 0.43 (95% CI 0.24 to 0.77)) and SSc-PAH (0.44 (0.22 to 0.89)). The most common AE was peripheral oedema, which was reported more frequently with initial combination therapy than monotherapy in the two PAH subgroups. The relative frequency of adverse events between those on combination therapy versus monotherapy was similar across subgroups., Conclusions: This post hoc subgroup analysis provides evidence that CTD-PAH and SSc-PAH patients benefit from initial ambrisentan and tadalafil combination therapy., Trial Registration Number: NCT01178073, post results., Competing Interests: Competing interests: JGC: grants and personal fees from Actelion and GlaxoSmithKline; personal fees from Bayer, Endotronix, Pfizer and United Therapeutics. NG: grants and personal fees from Actelion, Bayer, GlaxoSmithKline and Pfizer. JAB: personal fees from Actelion, Almirall, Bayer, GlaxoSmithKline and Pfizer; grants from Actelion, Bayer, GlaxoSmithKline and Pfizer. AEF: funds for the conduct of the study from Baylor College of Medicine; honoraria and travel/lodging expense for participating on the study's Steering Committee; grants from Actelion, Bayer, Gilead and United Therapeutics; personal fees from Actelion, Bayer, Gilead, Ikaria and United Therapeutics; non-financial support from Bayer and Novartis. H-AG: grants from Actelion, Bayer, Novartis and Pfizer; board membership and consultancy for Actelion, Bayer, GlaxoSmithKline, Merck, Novartis, Pfizer and Takeda; consultancy for Lilly; payment for lectures from Actelion, Bayer, GlaxoSmithKline, Lilly, Novartis and Pfizer. MMH: personal fees from Actelion, Bayer, Gilead, GlaxoSmithKline, Merck and Pfizer. MK: grants and personal fees from Actelion, Bayer and Pfizer; personal fees from GlaxoSmithKline. VVM: grants and personal fees from Actelion, Bayer, Gilead, Ikaria and United Therapeutics; grants from Novartis; personal fees from Steadymed and Akros. AJP: grants and personal fees from Actelion, Bayer, Gilead and GlaxoSmithKline; personal fees from United Therapeutics. GS: grants and personal fees from Actelion, Bayer, Gilead and GlaxoSmithKline. J-LV: grants from Actelion and GlaxoSmithKline; speaker fees from Actelion, Bayer, GlaxoSmithKline and Pfizer; advisory board honoraria from Actelion and Merck. CB: employee of Gilead; stock options in Gilead. HG: former employee of Gilead; patent pending in relation to the use of selective ERA's and PDE5 inhibitors. KLM: employee of Gilead; stock options in Gilead. JHNH: employee of GlaxoSmithKline; stock options in GlaxoSmithKline. JL: employee of GlaxoSmithKline. LJR: personal fees from Gilead., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Excessive exercise-induced hyperventilation and high prevalence of exercise oscillatory breathing (EOB) are present in patients with post-capillary pulmonary hypertension (PH) complicating left heart disease (LHD). Patients with pre-capillary PH have even higher hyperventilation but no EOB. We sought to determine the impact of a pre-capillary component of PH on ventilatory response to exercise in patients with PH and left heart disease., Methods: We retrospectively compared patients with idiopathic or heritable pulmonary arterial hypertension (PAH, n = 29), isolated post-capillary PH (IpcPH, n = 29), and combined post- and pre-capillary PH (CpcPH, n = 12). Diastolic pressure gradient (DPG = diastolic pulmonary artery pressure - pulmonary wedge pressure) was used to distinguish IpcPH (DPG <7 mm Hg) from CpcPH (DPG ≥7 mm Hg)., Results: Pulmonary vascular resistance (PVR) was higher in PAH, intermediate in CpcPH, and low in IpcPH. All patients with CpcPH but 1 had PVR >3 Wood unit. Exercise-induced hyperventilation (high minute ventilation over carbon dioxide production, low end-tidal carbon dioxide) was marked in PAH, intermediate in CpcPH, and low in IpcPH (p < 0.001) and correlated with DPG and PVR. Prevalence of EOB decreased from IpcPH to CpcPH to PAH (p < 0.001)., Conclusions: Patients with CpcPH may have worse hemodynamics than patients with IpcPH and distinct alterations of ventilatory control, consistent with more exercise-induced hyperventilation and less EOB. This might be explained at least in part by the presence and extent of pulmonary vascular disease., (Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: The VOLibris Tracking (VOLT) Study was an open-label, prospective, observational, multicenter, post-marketing registry program designed to more fully characterize the safety profile of ambrisentan for the treatment of pulmonary arterial hypertension (PAH). The key outcome was the incidence of aminotransferase elevations >3× the upper limit of normal (ULN)., Methods: In total, 999 patients from 115 centers in 15 countries, who were prescribed ambrisentan for the treatment of PAH (Functional Class II and III) between 30 June 2008 and 13 May 2011, were enrolled. Of these, 238 had PAH associated with connective tissue disease (PAH-CTD) and 220 had no prior PAH-specific therapy. Routine clinical monitoring data were collected by physicians., Results: The incidence of both alanine and aspartate aminotransferase events (>3× ULN) was 0.02 per patient-year (95% confidence interval 0.015 to 0.027). Similar results were reported for the PAH-CTD and PAH-specific-therapy-naive subgroups. Overall, 514 (52%) patients reported treatment-emergent adverse events of special interest, most commonly edema/fluid retention (249, or 25%) and anemia (143, or 14%)., Conclusions: Data from the VOLT study indicate no new ambrisentan-related safety signals. Ambrisentan was not associated with increases in liver function test abnormalities above the assumed background incidence of 1.5% per year, and the observed safety profile of ambrisentan was consistent with previously published data., (Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Pulmonary hypertension (PH) is a complex condition that can occur as a result of a wide range of disorders, including left heart disease, lung disease and chronic pulmonary thromboembolism. Contemporary PH patients are older and frequently have a multitude of comorbidities that may contribute to or simply coincide with their PH. Identifying the cause of PH in these complicated patients can be challenging but is essential, given that the aetiology of the disease has a significant impact on the management options available. In this article, we present two cases that highlight the difficulties involved in obtaining a precise diagnosis of the cause of PH within the setting of multiple comorbidities. The importance of performing a comprehensive, multidimensional diagnostic work-up is demonstrated, in addition to the need to specifically consider cardiopulmonary haemodynamic data in the context of the wider clinical picture. The article also illustrates why achieving an accurate diagnosis is necessary for optimal patient management. This may involve treatment of comorbidities as a priority, which can ameliorate the severity of PH, obviating the need to consider PH-targeted medical treatment., (Copyright ©ERS 2016.)

Heart failure (HF) is a clinical syndrome frequently associated with airway obstruction, either as a respiratory comorbidity or as a direct consequence of HF pathophysiology. Recognizing the relative contribution of an underlying airway disease as opposed to airway obstruction due to volume overload and left atrial pressure elevation is of importance for the appropriate management of patients affected by HF. This review focuses on "les liaisons dangereuses" between the heart and the lungs, outlying recent advances linking in a vicious circle of chronic obstructive lung disease (COPD) and obstructive sleep apnea (OSA) on one side and HF on the other side. It also discusses the role of pivotal diagnostic tools such as pulmonary function tests and cardiopulmonary exercise test to determine the contribution of HF and COPD to symptoms and clinical status. Treatment implications are discussed as well.

Aims: Pulmonary hypertension (PH) is a common complication of chronic hypoxic lung diseases. Bone morphogenetic protein (BMP) and endothelin-1 signaling pathways have been shown to be altered in hypoxic PH and to play crucial roles in the associated pulmonary artery remodeling. We, therefore, aimed to study the potential link between hypoxia and the alteration of BMP and endothelin-1 signaling observed in pulmonary artery smooth muscle cells (PA-SMCs) in hypoxic PH., Materials and Methods: Human PA-SMCs were treated with hypoxia-mimetic agent cobalt chloride (CoCl2; 100μM), with or without pretreatment with a dual endothelin receptor antagonist bosentan (10μM). Expressions of preproendothelin-1 (PPET1), BMP type 2 receptor (BMPR-2), and one BMP signaling target gene, the inhibitor of DNA binding 1 (ID1) were evaluated by real time quantitative polymerase chain reaction. BMP2-treated PA-SMCs were assessed for Smad1/5/8 signaling activation by Western Blotting., Key Findings: Treatment of PA-SMCs with CoCl2 increased PPET1 gene expression, while it did not alter expressions of endothelin converting enzyme, endothelin receptor type A or type B. Hypoxia-mimetic agent CoCl2 decreased the expressions of BMPR-2 and ID1 maximally after 3- and 6-hour treatment respectively, while CoCl2 treatment progressively increased noggin expression. Bosentan pretreatment restored expressions of BMPR-2 and ID1, as well as the activation (by phosphorylation) of Smad1/5/8 signaling induced by BMP2., Significance: Hypoxia induces the downregulation of the BMP signaling in PA-SMCs, at least, partly through the endothelin system. In hypoxic PH, increased endothelin-1 production might therefore contribute to the altered BMP signaling and subsequent PA-SMC hyperplasia., (Copyright © 2016 Elsevier Inc. All rights reserved.)