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Background: Balloon pulmonary angioplasty (BPA) has exhibited substantial progress in the management of chronic thromboembolic pulmonary hypertension (CTEPH). However, nearly one-half of the patients with CTEPH experience persistent pulmonary hypertension after undergoing BPA, emphasizing the need for enhanced therapies., Objectives: The authors sought to investigate the clinical significance of functional assessment-guided dilation of the pulmonary artery (PA) in patients with CTEPH undergoing BPA treatment., Methods: The prospective single-center cohort study enrolled 95 patients who underwent 278 consecutive BPA sessions. Lung parenchymal perfusion was assessed via 2-dimensional perfusion angiography, and pressure catheter measurements were taken to determine the PA pressure ratios. The correlation between lung perfusion and the pressure ratio was analyzed to establish an optimal target pressure ratio. Patients were stratified into 2 groups, a pressure-guided group (n = 28) and an angiographic group (n = 63), to evaluate whether optimizing the pressure ratio led to improvements in residual PH and complications., Results: The pressure ratio and lung perfusion measurements of 141 PA lesions were analyzed. A piecewise linear regression model identified a target pressure ratio of 0.7, associated with significant enhancement in lung perfusion. The pressure-guided strategy achieved a higher rate of mean pulmonary artery pressure <25 mm Hg (92.8% [26/28 patients] vs 60.3% [38/63 patients]; P = 0.001) and a concurrent reduction in BPA relevant complications (3.9% [4/101 sessions] vs 12.9% [23/177 sessions]; P = 0.019)., Conclusions: Functional assessment-guided PA dilation with a target pressure ratio of 0.7 proved beneficial in BPA treatment for patients with CTEPH. This approach improved the residual PH and reduced complications, highlighting its potential to enhance CTEPH management outcomes., Competing Interests: Funding Support and Author Disclosures The present study was supported by Japan Agency for Medical Research and Development under grant number 22ek0210149h0003. Dr S.Y. has received grants support from Takeda Pharmaceutical, Abbott, and Boston Scientific and lecture fees from Daiichi-Sankyo and Bristol Myers Squibb. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Hypoxic reprogramming of vasculature relies on genetic, epigenetic, and metabolic circuitry, but the control points are unknown. In pulmonary arterial hypertension (PAH), a disease driven by hypoxia inducible factor (HIF)-dependent vascular dysfunction, HIF-2α promoted expression of neighboring genes, long noncoding RNA (lncRNA) histone lysine N -methyltransferase 2E-antisense 1 ( KMT2E-AS1 ) and histone lysine N-methyltransferase 2E ( KMT2E ). KMT2E-AS1 stabilized KMT2E protein to increase epigenetic histone 3 lysine 4 trimethylation (H3K4me3), driving HIF-2α-dependent metabolic and pathogenic endothelial activity. This lncRNA axis also increased HIF-2α expression across epigenetic, transcriptional, and posttranscriptional contexts, thus promoting a positive feedback loop to further augment HIF-2α activity. We identified a genetic association between rs73184087, a single-nucleotide variant (SNV) within a KMT2E intron, and disease risk in PAH discovery and replication patient cohorts and in a global meta-analysis. This SNV displayed allele (G)-specific association with HIF-2α, engaged in long-range chromatin interactions, and induced the lncRNA-KMT2E tandem in hypoxic (G/G) cells. In vivo, KMT2E-AS1 deficiency protected against PAH in mice, as did pharmacologic inhibition of histone methylation in rats. Conversely, forced lncRNA expression promoted more severe PH. Thus, the KMT2E-AS1 /KMT2E pair orchestrates across convergent multi-ome landscapes to mediate HIF-2α pathobiology and represents a key clinical target in pulmonary hypertension.

Aims: The pathophysiology of pulmonary hypertension (PH) due to left-sided heart disease (Group 2 PH) is distinct from that of other groups of PH, yet there are still no approved therapies that selectively target pulmonary circulation. The increase in pulmonary capillary pressure due to left-sided heart disease is a trigger event for physical and biological alterations of the pulmonary circulation, including the nitric oxide (NO)-soluble guanylate cyclase-cyclic guanosine monophosphate axis. This study investigated inhaled NO vasoreactivity tests for patients with Group 2 PH and hypothesized that these changes may have a prognostic impact., Methods and Results: This was a single-centre, retrospective study with a median follow-up of 365 days. From January 2011 to December 2015, we studied 69 patients with Group 2 PH [age, 61.5 ± 13.0 (standard deviation) years; male:female, 49:20; left ventricular ejection fraction, 50.1 ± 20.4%; mean pulmonary arterial pressure, ≥25 mmHg; and pulmonary arterial wedge pressure (PAWP), >15 mmHg]. No adverse events were observed after NO inhalation. Thirty-four patients with Group 2 PH showed increased PAWP (ΔPAWP: 3.26 ± 2.22 mmHg), while the remaining 35 patients did not (ΔPAWP: -2.11 ± 2.29 mmHg). Multivariate analysis revealed that increased PAWP was the only significant predictor of all-cause death or hospitalization for heart failure (HF) after 1 year (hazard ratio 4.35; 95% confidence interval, 1.27-14.83; P = 0.019). The acute response of PAWP to NO differed between HF with preserved and reduced ejection fractions., Conclusions: Patients with Group 2 PH were tolerant of the inhaled NO test. NO-induced PAWP is a novel prognostic indicator., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background The symptom for identification of pulmonary arterial hypertension (PAH) is dyspnea on exertion, with a concomitant decrease in exercise capacity. Even patients with hemodynamically improved PAH may have impaired exercise tolerance; however, the effect of central and peripheral factors on exercise tolerance remains unclear. We explored the factors contributing to exercise capacity and ventilatory efficiency in patients with hemodynamically normalized PAH after medical treatment. Methods and Results In total, 82 patients with PAH (age: median 46 [interquartile range, 39-51] years; male:female, 23:59) and mean pulmonary arterial pressure ≤30 mm Hg at rest were enrolled. The exercise capacity, indicated by the 6-minute walk distance and peak oxygen consumption, and the ventilatory efficiency, indicated by the minute ventilation versus carbon dioxide output slope, were assessed using cardiopulmonary exercise testing with a right heart catheter. The mean pulmonary arterial pressure was 21 (17-25) mm Hg, and the 6-minute walk distance was 530 (458-565) m, whereas the peak oxygen consumption was 18.8 (14.8-21.6) mLꞏmin -1 ꞏkg -1 . The multivariate model that best predicted 6-minute walk distance included peak arterial mixed venous oxygen content difference (β=0.46, P <0.001), whereas the best peak oxygen consumption predictors included peak cardiac output (β=0.72, P <0.001), peak arterial mixed venous oxygen content difference (β=0.56, P <0.001), and resting mean pulmonary arterial pressure (β=-0.25, P =0.026). The parameter that best predicted minute ventilation versus carbon dioxide output slope was the resting mean pulmonary arterial pressure (β=0.35, P =0.041). Quadriceps muscle strength was moderately correlated with exercise capacity (6-minute walk distance; ρ=0.57, P <0.001; peak oxygen consumption: ρ=0.56, P <0.001) and weakly correlated with ventilatory efficiency (ρ = -0.32, P =0.007). Conclusions Central and peripheral factors are closely related to impaired exercise tolerance in patients with hemodynamically normalized PAH.

Background: Pulmonary hypertension (PH) is a common and morbid complication of left heart disease (LHD), comprising two subtypes: (1) isolated post-capillary pulmonary hypertension (Ipc-PH) and (2) combined post-capillary and pre-capillary pulmonary hypertension (Cpc-PH). Knowledge regarding the physiological characteristics that distinguish Cpc-PH, which has a worse prognosis, from Ipc-PH remains limited. Therefore, this study aimed to assess the utility of cardiopulmonary exercise testing (CPET) variables in detecting Cpc-PH., Methods and Results: Among 105 consecutive patients with LHD (age: 55 ± 13 years; male/female = 79/26) who underwent right heart catheterization and CPET, 45 (43%) were classified as PH-LHD (mean pulmonary artery pressure >20 mmHg). Ipc-PH (n = 24) was defined as pulmonary vascular resistance (PVR) ≤ 3 WU and Cpc-PH (n = 21) as PVR > 3 WU. Patients with Cpc-PH had a significantly lower peak partial pressure of carbon dioxide (PETCO2) (Non-PH/Ipc-PH/Cpc-PH = 38.2 ± 6.6 vs. 38.3 ± 6.0 vs 33.0 ± 4.4 mmHg, p = 0.006), higher VE vs. VCO2 slope (Non-PH/Ipc-PH/Cpc-PH = 33.0 [28.3, 36.6] vs. 32.5 [28.1, 37.8] vs. 40.6 [33.6, 46.1], p = 0.007), and lower ΔVO2/ΔWR (Non-PH/Ipc-PH/Cpc-PH = 8.5 ± 1.4 vs. 8.0 ± 1.7 vs. 6.8 ± 2.0 mL/min/watt, p = 0.001) than those with Ipc-PH and non-PH. Using multivariable logistic regression analysis, CPET variables were found to be independent predictors of Cpc-PH (lower peak PETCO2: odds ratio, 0.728 [95% confidence interval {CI}: 0.616-0.840], p = 0.003 and lower ΔVO2/ΔWR: odds ratio, 0.747 [95% CI: 0.575-0.872], p = 0.003)., Conclusion: From our exploratory analysis, CPET variables, especially in the lower peak PETCO2 and lower ΔVO2/ΔWR, were associated with Cpc-PH in patients with left heart disease., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Goda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest in this work that could be perceived as prejudicing the impartiality of the research reported., (Copyright © 2022. Published by Elsevier Ltd.)

Background Whether pulmonary hemodynamic parameters and functional capacity are associated with quality of life in patients with chronic thromboembolic pulmonary hypertension remains unknown. This study aimed to evaluate disease-specific quality of life using the emPHasis-10 questionnaire and assess its determinants in patients with chronic thromboembolic pulmonary hypertension with normalized pulmonary hemodynamics. Methods and Results This cross-sectional study included 187 health status assessments of 143 patients with chronic thromboembolic pulmonary hypertension (median age, 68 [58-75] years; men/women, 51/136; use of home oxygen therapy, 51 patients [27%]) after balloon pulmonary angioplasty with normalized mean pulmonary artery pressure <25 mm Hg at rest. Right heart catheterization was performed, followed by assessment of 6-minute walk distance and the emPHasis-10 questionnaire. The median pulmonary artery pressure and pulmonary vascular resistance were 18 (15-21) mm Hg and 2.2 (1.7-2.9) wood units, respectively. The median emPHasis-10 score was 14 (8-24), whereas the median 6-minute walk distance was 447 (385-517) m. Univariate linear regression analysis showed that the emPHasis-10 score was associated with 6-minute walk distance (β=-0.476 [95% CI -0.604, -0.348], P <0.001) and home oxygen therapy (β=0.214 [95% CI, 0.072, 0.356], P =0.003) but not with hemodynamic parameters. Multiple regression analysis revealed that a higher emPHasis-10 score was associated with lower 6-minute walk distance (β=-0.475 [95% CI, -0.631 to -0.319], P <0.001). Conclusions Health-related quality of life was associated with exercise capacity and the use of home oxygen therapy, but not with hemodynamic parameters, in patients with chronic thromboembolic pulmonary hypertension and normalized hemodynamics after balloon pulmonary angioplasty. Improvements in exercise capacity may lead to further improvements in quality of life.

Despite the poor prognosis of systemic sclerosis (SSc) due to the co-occurrence of left ventricular diastolic dysfunction (LVDD), presence of occult LVDD has not been sufficiently investigated. This retrospective study aimed to reveal the prevalence and determinants of occult LVDD in patients with SSc by exercise stress test. Forty-five SSc patients (age, 63 ± 13 years; men/women, 6/39) with normal pulmonary artery pressure and pulmonary artery wedge pressure (PAWP) at rest underwent a symptom-limited exercise test with right heart catheterization using a supine cycle ergometer; haemodynamic parameters at rest, leg raise and during exercise were evaluated. Occult LVDD defined PAWP ≥ 25 mmHg during exercise was seen in 13 patients (29%). Higher PAWP, lower pulmonary vascular resistance and diastolic pulmonary pressure gradient, larger left atrium at rest, and higher PAWP during leg raise (15 ± 4 vs 10 ± 4 mmHg in non-LVDD group, p < 0.001) were observed in the occult LVDD group. The area under the ROC curve for PAWP after leg raise was largest at 0.83 (95% CI: 0.70-0.95, p = 0.001). About one-third (29%) of SSc patients with normal haemodynamics at rest showed occult LVDD. A higher PAWP after leg raise could be useful for detecting occult LVDD., (© 2022. The Author(s).)

Continuous infusion of intravenous epoprostenol (EPO) improves exercise capacity and survival in pulmonary arterial hypertension (PAH); however, it is associated with side effects. This study aimed to describe our experience on safe EPO withdrawal with the aid of an exercise stress test. This retrospective review included patients with PAH who were successfully withdrawn from EPO. Haemodynamic data were obtained before EPO administration, at withdrawal, and after discontinuation. After the mean pulmonary arterial pressure (mPAP) decreased to <25 mmHg for at least 1 year, an exercise test under right heart catheterisation was performed. If exercise pulmonary hypertension was not record (mPAP - cardiac output slope < 3), EPO was withdrawn. Of the 99 patients who received EPO, ten were identified as having undergone withdrawal or termination. mPAP decreased from 61 (54-71) mmHg before treatment to 19 (17-21) mmHg before withdrawal and remained unchanged, at 19 (14-23) mmHg, 1 year after EPO discontinuation. After a median follow-up of 32 months, all the patients survived. Patients with PAH who recovered their normal haemodynamic function were safely withdrawn from EPO with the aid of an exercise stress test., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Many patients with heart failure with preserved ejection fraction have metabolic syndrome and develop exercise-induced pulmonary hypertension (EIPH). Increases in pulmonary vascular resistance in patients with heart failure with preserved ejection fraction portend a poor prognosis; this phenotype is referred to as combined precapillary and postcapillary pulmonary hypertension (CpcPH). Therapeutic trials for EIPH and CpcPH have been disappointing, suggesting the need for strategies that target upstream mechanisms of disease. This work reports novel rat EIPH models and mechanisms of pulmonary vascular dysfunction centered around the transcriptional repression of the soluble guanylate cyclase (sGC) enzyme in pulmonary artery (PA) smooth muscle cells., Methods: We used obese ZSF-1 leptin-receptor knockout rats (heart failure with preserved ejection fraction model), obese ZSF-1 rats treated with SU5416 to stimulate resting pulmonary hypertension (obese+sugen, CpcPH model), and lean ZSF-1 rats (controls). Right and left ventricular hemodynamics were evaluated using implanted catheters during treadmill exercise. PA function was evaluated with magnetic resonance imaging and myography. Overexpression of nuclear factor Y α subunit (NFYA), a transcriptional enhancer of sGC β1 subunit (sGCβ1), was performed by PA delivery of adeno-associated virus 6. Treatment groups received the SGLT2 inhibitor empagliflozin in drinking water. PA smooth muscle cells from rats and humans were cultured with palmitic acid, glucose, and insulin to induce metabolic stress., Results: Obese rats showed normal resting right ventricular systolic pressures, which significantly increased during exercise, modeling EIPH. Obese+sugen rats showed anatomic PA remodeling and developed elevated right ventricular systolic pressure at rest, which was exacerbated with exercise, modeling CpcPH. Myography and magnetic resonance imaging during dobutamine challenge revealed PA functional impairment of both obese groups. PAs of obese rats produced reactive oxygen species and decreased sGCβ1 expression. Mechanistically, cultured PA smooth muscle cells from obese rats and humans with diabetes or treated with palmitic acid, glucose, and insulin showed increased mitochondrial reactive oxygen species, which enhanced miR-193b-dependent RNA degradation of nuclear factor Y α subunit (NFYA), resulting in decreased sGCβ1-cGMP signaling. Forced NYFA expression by adeno-associated virus 6 delivery increased sGCβ1 levels and improved exercise pulmonary hypertension in obese+sugen rats. Treatment of obese+sugen rats with empagliflozin improved metabolic syndrome, reduced mitochondrial reactive oxygen species and miR-193b levels, restored NFYA/sGC activity, and prevented EIPH., Conclusions: In heart failure with preserved ejection fraction and CpcPH models, metabolic syndrome contributes to pulmonary vascular dysfunction and EIPH through enhanced reactive oxygen species and miR-193b expression, which downregulates NFYA-dependent sGCβ1 expression. Adeno-associated virus-mediated NFYA overexpression and SGLT2 inhibition restore NFYA-sGCβ1-cGMP signaling and ameliorate EIPH.

Background: Despite improved survival for patients with chronic thromboembolic pulmonary hypertension (CTEPH) due to progressive medical and interventional treatment, impaired exercise capacity remains common due to poorly understood mechanisms. We aimed to clarify the exercise capacity of CTEPH patients with near-normal pulmonary hemodynamics and evaluate its determinants among the hemodynamic, peripheral (e.g., oxygen use by the peripheral tissues), and muscular (e.g., skeletal muscle strength) factors., Methods: Three hundred and twenty-nine patients with CTEPH (mean age, 63 ± 12 years; men/women, 73/256) with a near-normal mean pulmonary artery pressure (≤30 mm Hg) at rest were enrolled. We assessed exercise capacity by peak oxygen consumption (peak VO 2 ) using cardiopulmonary exercise testing with a right heart catheter. We also measured the 6-minute walk distance (6MWD) and quadriceps muscle strength., Results: The mean pulmonary artery pressure was 19 ± 4 mmHg and mean cardiac output was 4.8 ± 1.5 L/min at rest. The mean 6MWD was 444 ± 101 m, while the mean peak VO 2 was 14.4 ± 3.9 mL/min/kg. A multivariate model that predicted 6MWD included quadriceps strength (β = 0.45, p < 0.001) and peak arterial venous oxygen difference (β = 0.29, p < 0.001). In contrast, the peak VO 2 was best correlated with mPAP-CO slope (β = -0.30, p < 0.001), followed by quadriceps strength and peak arterial venous oxygen difference., Conclusions: The 6MWD performance may be significantly influenced by peripheral oxygen use and muscular factors, while peak VO 2 is influenced by hemodynamic and peripheral factors in CTEPH patients with near-normal hemodynamics., Competing Interests: Financial conflict of interest statement The authors declare no potential conflicts of interest related to any company or organization whose products or services are discussed in this article., (Copyright © 2021. Published by Elsevier Inc.)

Ophiocordyceps sinensis (OCS), an entomopathogenic fungus, is known to exert antiproliferative and antitissue remodeling effects. Vascular remodeling and vasoconstriction play critical roles in the development of pulmonary hypertension (PH). The therapeutic potential of OCS for PH was investigated using rodent PH models, and cultured pulmonary artery endothelial and smooth muscle cells (PAECs and PASMCs), with a focus on the involvement of TRPM7. OCS ameliorated the development of PH, right ventricular hypertrophy and dysfunction in the monocrotaline-induced PH rats. The genetic knockout of TRPM7 attenuated the development of PH in mice with monocrotaline pyrrole-induced PH. TRPM7 was associated with medial hypertrophy and the plexiform lesions in rats and humans with PH. OCS suppressed proliferation of PASMCs derived from the PH patients. Ethanol extracts of OCS inhibited TRPM7-like current, TGF-β2-induced endothelial-mesenchymal transition, IL-6-induced STAT3 phosphorylation, and PDGF-induced Akt phosphorylation in PAECs or PASMCs. These inhibitory effects were recapitulated by either siRNA-mediated TRPM7 knockdown or treatment with TRPM7 antagonist FTY-720. OCS and FTY-720 induced vasorelaxation in the isolated normal human pulmonary artery. As a result, the present study proposes the therapeutic potential of OCS for the treatment of PH. The inhibition of TRPM7 is suggested to underlie the therapeutic effect of OCS., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

The dynamic regulation of endothelial pathophenotypes in pulmonary hypertension (PH) remains undefined. Cellular senescence is linked to PH with intracardiac shunts; however, its regulation across PH subtypes is unknown. Since endothelial deficiency of iron-sulfur (Fe-S) clusters is pathogenic in PH, we hypothesized that a Fe-S biogenesis protein, frataxin (FXN), controls endothelial senescence. An endothelial subpopulation in rodent and patient lungs across PH subtypes exhibited reduced FXN and elevated senescence. In vitro, hypoxic and inflammatory FXN deficiency abrogated activity of endothelial Fe-S-containing polymerases, promoting replication stress, DNA damage response, and senescence. This was also observed in stem cell-derived endothelial cells from Friedreich's ataxia (FRDA), a genetic disease of FXN deficiency, ataxia, and cardiomyopathy, often with PH. In vivo, FXN deficiency-dependent senescence drove vessel inflammation, remodeling, and PH, whereas pharmacologic removal of senescent cells in Fxn-deficient rodents ameliorated PH. These data offer a model of endothelial biology in PH, where FXN deficiency generates a senescent endothelial subpopulation, promoting vascular inflammatory and proliferative signals in other cells to drive disease. These findings also establish an endothelial etiology for PH in FRDA and left heart disease and support therapeutic development of senolytic drugs, reversing effects of Fe-S deficiency across PH subtypes.

Background: There is limited evidence for pulmonary arterial hypertension (PAH)-targeted therapy in patients with pulmonary hypertension associated with respiratory disease (R-PH). Therefore, we conducted a multicenter prospective study of patients with R-PH to examine real-world characteristics of responders by evaluating demographics, treatment backgrounds, and prognosis., Methods and results: Among the 281 patients with R-PH included in this study, there was a treatment-naïve cohort of 183 patients with normal pulmonary arterial wedge pressure and 1 of 4 major diseases (chronic obstructive pulmonary diseases, interstitial pneumonia [IP], IP with connective tissue disease, or combined pulmonary fibrosis with emphysema); 43% of patients had mild ventilatory impairment (MVI), whereas 52% had a severe form of PH. 68% received PAH-targeted therapies (mainly phosphodiesterase-5 inhibitors). Among patients with MVI, those treated initially (i.e., within 2 months of the first right heart catheterization) had better survival than patients not treated initially (3-year survival 70.6% vs. 34.2%; P=0.01); there was no significant difference in survival in the group with severe ventilatory impairment (49.6% vs. 32.1%; P=0.38). Responders to PAH-targeted therapy were more prevalent in the group with MVI., Conclusions: This first Japanese registry of R-PH showed that a high proportion of patients with MVI (PAH phenotype) had better survival if they received initial treatment with PAH-targeted therapies. Responders were predominant in the group with MVI.

Background Although chronic thromboembolic pulmonary hypertension (CTEPH) and acute pulmonary embolism (APE) share some clinical manifestations, a limited proportion of patients with CTEPH have a history of APE. Moreover, in histopathologic studies, it has been revealed that pulmonary vasculature lesions similar to pulmonary arterial hypertension existed in patients with CTEPH. Thus, it remains unknown whether these 3 disorders also share genetic backgrounds. Methods and Results Whole exome screening was performed with DNA isolated from 51 unrelated patients with CTEPH of Japanese ancestry. The frequency of genetic variants associated with pulmonary arterial hypertension or APE in patients with CTEPH was compared with those in the integrative Japanese Genome Variation Database 3.5KJPN. Whole exome screening analysis showed 17 049 nonsynonymous variants in patients with CTEPH. Although we found 6 nonsynonymous variants that are associated with APE in patients with CTEPH, there was no nonsynonymous variant associated with pulmonary arterial hypertension. Patients with CTEPH with a history of APE had nonsynonymous variants of F5 , which encodes factor V. In contrast, patients with CTEPH without a history of APE had a nonsynonymous variant of THBD , which encodes thrombomodulin. Moreover, thrombin-activatable fibrinolysis inhibitor, which is one of the pathogenic proteins in CTEPH, was significantly more activated in those who had the variants of THBD compared with those without it. Conclusions These results provide the first evidence that patients with CTEPH have some variants associated with APE, regardless of the presence or absence of a history of APE. Furthermore, the variants might be different between patients with CTEPH with and without a history of APE.

Background: Selexipag is an oral prostacyclin receptor (IP receptor) agonist with a non-prostanoid structure. This study examined its efficacy and safety in Japanese patients with non-operated or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH)., Methods and results: This Phase II study was a randomized, double-blind, placebo-controlled parallel-group comparison. The primary endpoint was a change in pulmonary vascular resistance (PVR) from baseline to week 17. The main analysis involved a per-protocol set group of 28 subjects. The change in PVR (mean±SD) after 17 weeks of treatment in the selexipag group was -104±191 dyn·s/cm 5 , whereas that in the placebo group was 26±180 dyn·s/cm 5 . Thus, the treatment effect after 17 weeks of selexipag treatment was calculated as -130±189 dyn·s/cm 5 (P=0.1553). Although the primary endpoint was not met, for the group not concomitantly using a pulmonary vasodilator the PVR in the selexipag group was significantly decreased compared with placebo group (P=0.0364). The selexipag group also showed improvement in total pulmonary resistance and cardiac index., Conclusions: Selexipag treatment improved pulmonary hemodynamics in Japanese patients with CTEPH, but PVR did not show a significant difference between the selexipag and placebo groups. (Trial registration: JAPIC Clinical Trials Information [JapicCTI-111667]).

Introduction: Exercise pulmonary hypertension is common in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who experience shortness of breath during exercise and reduced exercise capacity despite normalised pulmonary arterial pressure (PAP) at rest; however, the relationship between exercise pulmonary hypertension and exercise capacity remains unclear. Here we aimed to determine whether exercise pulmonary hypertension is related to exercise capacity and ventilatory efficiency in CTEPH patients with normalised resting haemodynamics after pulmonary balloon angioplasty (BPA)., Patients and Methods: In total, 249 patients with CTEPH treated with BPA (mean±sd age 63±14 years; male:female 62:187) with normal mean PAP (mPAP) (<25 mmHg) and pulmonary arterial wedge pressure (≤15 mmHg) at rest underwent cardiopulmonary exercise testing with right heart catheterisation. mPAP-cardiac output (CO) during exercise was plotted using multipoint plots. Exercise pulmonary hypertension was defined by a mPAP-CO slope >3.0., Results: At rest, pulmonary vascular resistance was significantly higher in the exercise pulmonary hypertension group (n=116) than in the non-exercise pulmonary hypertension group (n=133). Lower peak oxygen consumption (13.5±3.8 versus 16.6±4.7 mL·min -1 ·kg -1 ; p<0.001) was observed in the former group. The mPAP-CO slope was negatively correlated with peak oxygen consumption (r= -0.45, p<0.001) and positively correlated with the minute ventilation versus carbon dioxide output slope (r=0.39, p<0.001)., Conclusions: Impaired exercise capacity and ventilatory efficiency were observed in patients with CTEPH who had normalised PAP at rest but exercise pulmonary hypertension., Competing Interests: Conflict of interest: H. Kikuchi has nothing to disclose. Conflict of interest: A. Goda has nothing to disclose. Conflict of interest: K. Takeuchi has nothing to disclose. Conflict of interest: T. Inami has nothing to disclose. Conflict of interest: T. Kohno has nothing to disclose. Conflict of interest: K. Sakata has nothing to disclose. Conflict of interest: K. Soejima has nothing to disclose. Conflict of interest: T. Satoh has nothing to disclose., (Copyright ©ERS 2020.)

Objective: Pulmonary hypertension (PH) due to left heart disease (group 2), especially in the setting of heart failure with preserved ejection fraction (HFpEF), is the most common cause of PH worldwide; however, at present, there is no proven effective therapy available for its treatment. PH-HFpEF is associated with insulin resistance and features of metabolic syndrome. The stable prostacyclin analog, treprostinil, is an effective and widely used Food and Drug Administration-approved drug for the treatment of pulmonary arterial hypertension. While the effect of treprostinil on metabolic syndrome is unknown, a recent study suggests that the prostacyclin analog beraprost can improve glucose intolerance and insulin sensitivity. We sought to evaluate the effectiveness of treprostinil in the treatment of metabolic syndrome-associated PH-HFpEF. Approach and Results: Treprostinil treatment was given to mice with mild metabolic syndrome-associated PH-HFpEF induced by high-fat diet and to SU5416/obese ZSF1 rats, a model created by the treatment of rats with a more profound metabolic syndrome due to double leptin receptor defect (obese ZSF1) with a vascular endothelial growth factor receptor blocker SU5416. In high-fat diet-exposed mice, chronic treatment with treprostinil reduced hyperglycemia and pulmonary hypertension. In SU5416/Obese ZSF1 rats, treprostinil improved hyperglycemia with similar efficacy to that of metformin (a first-line drug for type 2 diabetes mellitus); the glucose-lowering effect of treprostinil was further potentiated by the combined treatment with metformin. Early treatment with treprostinil in SU5416/Obese ZSF1 rats lowered pulmonary pressures, and a late treatment with treprostinil together with metformin improved pulmonary artery acceleration time to ejection time ratio and tricuspid annular plane systolic excursion with AMPK (AMP-activated protein kinase) activation in skeletal muscle and the right ventricle., Conclusions: Our data suggest a potential use of treprostinil as an early treatment for mild metabolic syndrome-associated PH-HFpEF and that combined treatment with treprostinil and metformin may improve hyperglycemia and cardiac function in a more severe disease.

Background: Although cardiac troponin and natriuretic peptide have been shown to decrease after balloon pulmonary angioplasty (BPA) with improved right ventricular afterload in chronic thromboembolic pulmonary hypertension (CTEPH), biomarkers to evaluate the effects of BPA independently of heart failure status remain to be developed., Methods: In 39 consecutive CTEPH patients including 31 who underwent BPA, we measured plasma levels of cyclophilin A (CyPA), which we demonstrated is secreted from pulmonary vascular smooth muscle cells in response to mechanical stretch and hypoxia., Results: CyPA levels were elevated in CTEPH patients (12.7, IQR: 7.6-16.0) compared with 8 thromboembolic controls with a history of venous thromboembolism (4.9, IQR: 2.4-11.2) or 18 healthy controls (4.1, IQR: 2.4-6.8) (both p< 0.05) and were linearly correlated with mean pulmonary arterial pressure (r=0.50, p = 0.0003) and pulmonary vascular resistance (r=0.32, p= 0.026). BPA reduced CyPA levels and tended to lower brain-type natriuretic peptide (BNP) levels (p< 0.01 and p = 0.07). When comparing the changes in CyPA before and after BPA in the two subgroups with higher (≥35pg/mL) and normal (<35pg/mL) BNP at baseline, CyPA decreased both in patients with higher BNP and those with normal BNP (both p< 0.05). In contrast, BNP decreased only in patients with higher BNP (p< 0.05). Also, CyPA decreased both in patients with lower (<25 kg/m 2 ) and higher (≥25kg/m 2 ) body mass index (BMI) at baseline (both p<0.05), whereas BPA tended to reduce BNP in patients with lower BMI (p = 0.12) but not in those with higher BMI (p = 0.55)., Conclusions: CyPA could be a useful biomarker to evaluate the effects of BPA even in patients with normal BNP or high BMI., (Copyright © 2019 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Objective: Despite the recent progress in upfront combination therapy for pulmonary arterial hypertension (PAH), useful biomarkers for the disorder still remain to be developed. SeP (Selenoprotein P) is a glycoprotein secreted from various kinds of cells including pulmonary artery smooth muscle cells to maintain cellular metabolism. We have recently demonstrated that SeP production from pulmonary artery smooth muscle cells is upregulated and plays crucial roles in the pathogenesis of PAH. However, it remains to be elucidated whether serum SeP levels could be a useful biomarker for PAH. Approach and Results: We measured serum SeP levels and evaluated their prognostic impacts in 65 consecutive patients with PAH and 20 controls during follow-up (mean, 1520 days; interquartile range, 1393-1804 days). Serum SeP levels were measured using a newly developed sol particle homogeneous immunoassay. The patients with PAH showed significantly higher serum SeP levels compared with controls. Higher SeP levels (cutoff point, 3.47 mg/L) were associated with the outcome (composite end point of all-cause death and lung transplantation) in patients with PAH (hazard ratio, 4.85 [1.42-16.6]; P <0.01). Importantly, we found that the absolute change in SeP of patients with PAH (ΔSeP) in response to the initiation of PAH-specific therapy significantly correlated with the absolute change in mean pulmonary artery pressure, pulmonary vascular resistance (ΔPVR), and cardiac index (ΔCI; R =0.78, 0.76, and -0.71 respectively, all P <0.0001). Moreover, increase in ΔSeP during the follow-up predicted poor outcome of PAH., Conclusions: Serum SeP is a novel biomarker for diagnosis and assessment of treatment efficacy and long-term prognosis in patients with PAH.

Background: Exercise-induced pulmonary hypertension (PH) is often seen in chronic thromboembolic PH (CTEPH) patients with normalized resting hemodynamics, but it is difficult to differentiate precapillary PH as pulmonary vascular dysfunction and post-capillary PH from occult-left ventricular dysfunction (LVD). The aim of this study was to examine whether the exercise-induced elevation of pulmonary arterial wedge pressure (PAWP) can be predicted by the echocardiographic index at rest., Methods and results: A total of 71 CTEPH patients (67±11 years old, male/female=15/56) treated by pulmonary angioplasty with near-normal pulmonary arterial pressure (PAP) and normal PAWP at rest underwent symptom-limited exercise test using supine cycle ergometer with right heart catheterization. Exercise-induced elevation in PAWP of >20 mmHg during exercise was defined as occult-LVD. Resting echocardiography was performed within 3 months. In the occult-LVD (n=28), PAWP at rest after leg raising for exercise (14±4 vs. 11±3 mmHg, P<0.001), and mean PAP during exercise were higher compared with the non-LVD (n=43). Peak oxygen consumption, cardiac output, and pulmonary vascular resistance at peak exercise did not differ between groups. Left atrial volume index (LAVi) in the occult-LVD was significantly larger (39.7±8.1 vs. 34.4±9.6 mL/m 2 , P=0.017). LAVi correlated with exercise PAWP (r=0.356, P=0.002), but not resting PAWP (r=0.161, P=0.179)., Conclusions: Larger left atrial volume may reflect the exercise-induced PAWP elevation as occult-LVD in CTEPH patients.

Objective: Excessive proliferation and apoptosis resistance are special characteristics of pulmonary artery smooth muscle cells (PASMCs) in pulmonary arterial hypertension (PAH). However, the drugs in clinical use for PAH target vascular dilatation, which do not exert adequate effects in patients with advanced PAH. Here, we report a novel therapeutic effect of emetine, a principal alkaloid extracted from the root of ipecac clinically used as an emetic and antiprotozoal drug. Approach and Results: We performed stepwise screenings for 5562 compounds from original library. First, we performed high-throughput screening with PASMCs from patients with PAH (PAH-PASMCs) and found 80 compounds that effectively inhibited proliferation. Second, we performed the repeatability and counter assay. Finally, we performed a concentration-dependent assay and found that emetine inhibits PAH-PASMC proliferation. Interestingly, emetine significantly reduced protein levels of HIFs (hypoxia-inducible factors; HIF-1α and HIF-2α) and downstream PDK1 (pyruvate dehydrogenase kinase 1). Moreover, emetine significantly reduced the protein levels of RhoA (Ras homolog gene family, member A), Rho-kinases (ROCK1 and ROCK2 [rho-associated coiled-coil containing protein kinases 1 and 2]), and their downstream CyPA (cyclophilin A), and Bsg (basigin) in PAH-PASMCs. Consistently, emetine treatment significantly reduced the secretion of cytokines/chemokines and growth factors from PAH-PASMCs. Interestingly, emetine reduced protein levels of BRD4 (bromodomain-containing protein 4) and downstream survivin, both of which are involved in many cellular functions, such as cell cycle, apoptosis, and inflammation. Finally, emetine treatment ameliorated pulmonary hypertension in 2 experimental rat models, accompanied by reduced inflammatory changes in the lungs and recovered right ventricular functions., Conclusions: Emetine is an old but novel drug for PAH that reduces excessive proliferation of PAH-PASMCs and improves right ventricular functions.

In recent years, therapeutic options for patients with chronic thromboembolic pulmonary hypertension (CTEPH) have expanded with the development of catheter-based interventional therapy, namely balloon pulmonary angioplasty (BPA), also called percutaneous transluminal pulmonary angioplasty. For CTEPH patients with technically inoperable disease or with an unfavorable risk-to-benefit ratio for surgical pulmonary endarterectomy, BPA is an important alternative therapeutic strategy. One important treatment goal of BPA should be the relief of pulmonary hypertension. However, the indications for BPA in specialized Japanese centers currently go beyond the sole indication of relieving pulmonary hypertension. BPA is currently limited to specific institutes and experienced operators, which allows better management of its associated complications of reperfusion pulmonary edema and vascular injury using various strategies based on past experiences. This article discusses the latest indications and treatment goals of BPA and the current flow diagram for therapeutic decision-making in CTEPH, and summarizes the factors to be considered when performing BPA, from a Japanese perspective., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Deficiencies of iron-sulfur (Fe-S) clusters, metal complexes that control redox state and mitochondrial metabolism, have been linked to pulmonary hypertension (PH), a deadly vascular disease with poorly defined molecular origins. BOLA3 (BolA Family Member 3) regulates Fe-S biogenesis, and mutations in BOLA3 result in multiple mitochondrial dysfunction syndrome, a fatal disorder associated with PH. The mechanistic role of BOLA3 in PH remains undefined., Methods: In vitro assessment of BOLA3 regulation and gain- and loss-of-function assays were performed in human pulmonary artery endothelial cells using siRNA and lentiviral vectors expressing the mitochondrial isoform of BOLA3. Polymeric nanoparticle 7C1 was used for lung endothelium-specific delivery of BOLA3 siRNA oligonucleotides in mice. Overexpression of pulmonary vascular BOLA3 was performed by orotracheal transgene delivery of adeno-associated virus in mouse models of PH., Results: In cultured hypoxic pulmonary artery endothelial cells, lung from human patients with Group 1 and 3 PH, and multiple rodent models of PH, endothelial BOLA3 expression was downregulated, which involved hypoxia inducible factor-2α-dependent transcriptional repression via histone deacetylase 1-mediated histone deacetylation. In vitro gain- and loss-of-function studies demonstrated that BOLA3 regulated Fe-S integrity, thus modulating lipoate-containing 2-oxoacid dehydrogenases with consequent control over glycolysis and mitochondrial respiration. In contexts of siRNA knockdown and naturally occurring human genetic mutation, cellular BOLA3 deficiency downregulated the glycine cleavage system protein H, thus bolstering intracellular glycine content. In the setting of these alterations of oxidative metabolism and glycine levels, BOLA3 deficiency increased endothelial proliferation, survival, and vasoconstriction while decreasing angiogenic potential. In vivo, pharmacological knockdown of endothelial BOLA3 and targeted overexpression of BOLA3 in mice demonstrated that BOLA3 deficiency promotes histological and hemodynamic manifestations of PH. Notably, the therapeutic effects of BOLA3 expression were reversed by exogenous glycine supplementation., Conclusions: BOLA3 acts as a crucial lynchpin connecting Fe-S-dependent oxidative respiration and glycine homeostasis with endothelial metabolic reprogramming critical to PH pathogenesis. These results provide a molecular explanation for the clinical associations linking PH with hyperglycinemic syndromes and mitochondrial disorders. These findings also identify novel metabolic targets, including those involved in epigenetics, Fe-S biogenesis, and glycine biology, for diagnostic and therapeutic development.

A revised diagnostic algorithm provides guidelines for the diagnosis of patients with suspected pulmonary hypertension, both prior to and following referral to expert centres, and includes recommendations for expedited referral of high-risk or complicated patients and patients with confounding comorbidities. New recommendations for screening high-risk groups are given, and current diagnostic tools and emerging diagnostic technologies are reviewed., Competing Interests: Conflict of interest: A. Frost reports personal fees and non-financial support (travel and lodging for attendance and participation in the 6th WSPH) from Actelion, Gilead, United Therapeutics and Bayer, honoraria for presentations from Gilead, and honoraria for participation in an end-point adjudication committee for an FDA-approved study from United Therapeutics, during the conduct of the study; and personal fees (honoraria and travel and lodging for presentations at meetings) from Actelion Pharmaceuticals, outside the submitted work. Conflict of interest: D. Badesch reports grants and personal fees (as steering committee member and site investigator) from Acceleron, Complexa, Bellerophon and Liquidia, grants, personal fees and advisory board work from Actelion, is a long-term stock holder of Johnson and Johnson, grants and personal fees (as advisory board member and site investigator) from Arena, Gilead and United Therapeutics/Lung LLC, personal fees for consultancy from Respira, grants and personal fees (as site investigator, advisory board member and consultant) from Bayer, outside the submitted work. Conflict of interest: J.S.R. Gibbs reports grants and personal fees from Actelion, GSK, MSD and Pfizer, personal fees from Arena, Bayer, Bellerophon, Complexa and Acceleron, and grants from United Therapeutics, during the conduct of the study. Conflict of interest: D. Gopalan has nothing to disclose. Conflict of interest: D. Khanna reports personal fees from Actelion, Bayer, Boehringer Ingelheim, Chemomab, Corbus, Covis, Cytori, EMD Sereno, Genentech/Roche, Gilead, GSK, Sanofi-Aventis and UCB Pharma; grants from Bayer, Boehringer Ingelheim, Genentech/Roche, Pfizer and Sanofi-Aventis; and has stock options with Eicos Sciences, Inc. He was also supported by the NIH/NIAMS (K24 AR063120). Conflict of interest: A. Manes reports grants and personal fees from Actelion, and grants from Bayer and Pfizer, outside the submitted work. Conflict of interest: R. Oudiz reports grants and consulting and speaker fees from Actelion, Gilead and United Therapeutics, grants from Aadi and GSK, consulting fees from Complexa, Acceleron and Medtronic, and grants and consulting fees from Arena and Reata, outside the submitted work. Conflict of interest: T. Satoh has nothing to disclose. Conflict of interest: F. Torres reports personal fees from Actelion, Bayer, Reata and Arena, and grants from Gilead, United Therapeutics, Medtronic, Eiger and Bellerophon, during the conduct of the study. Conflict of interest: A. Torbicki reports personal fees from Actelion, AOP Orphan Pharmaceutics, Bayer and MSD, and non-financial support from Pfizer, outside the submitted work; and is also a chairperson of the Foundation for Pulmonary Hypertension, which receives donations from outside parties to support its activities. The chair receives no financial compensation for this function., (Copyright ©ERS 2019.)

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are fatal diseases; however, their pathogenesis still remains to be elucidated. We have recently screened novel pathogenic molecules and have performed drug discovery targeting those molecules. Pulmonary artery smooth muscle cells (PASMCs) in patients with PAH (PAH-PASMCs) have high proliferative properties like cancer cells, which leads to thickening and narrowing of distal pulmonary arteries. Thus, we conducted a comprehensive analysis of PAH-PASMCs and lung tissues to search for novel pathogenic proteins. We validated the pathogenic role of the selected proteins by using tissue-specific knockout mice. To confirm its clinical significance, we used patient-derived blood samples to evaluate the potential as a biomarker for diagnosis and prognosis. Finally, we conducted a high throughput screening and found inhibitors for the pathogenic proteins.

Cardiopulmonary exercise testing (CPX) with right heart catheterization (RHC) widely used for early diagnosis and evaluation of pulmonary vascular disease in patients with pulmonary arterial hypertension and early stage heart failure with preserved ejection fraction, who display normal hemodynamics at rest. The aim of this study was to investigate that whether body position affects pulmonary hemodynamics, pulmonary arterial wedge pressure (PAWP), and CPX parameters during invasive CPX. Seventeen patients (58 ± 14 years; 5/12 male/female) with chronic thromboembolic pulmonary hypertension treated with percutaneous transluminal pulmonary angioplasty and near-normal pulmonary artery pressure (PAP) underwent invasive CPX twice in supine and upright position using a cycle ergometer with 6 months interval. The mean PAP (peak: 45 ± 7 vs. 40 ± 11 mmHg, P = 0.006) and PAWP (peak: 17 ± 4 vs. 11 ± 7 mmHg, P = 0.008, supine vs. upright, respectively) throughout the test in supine position were significantly higher compared with in upright position, because of preload increase. However, transpulmonary pressure gradient, pulmonary vascular resistance, and mPA-Q slope during exercise were of no significant difference between two positions. There were no differences between the results of two positions in peak VO 2 (15.9 ± 4.0 vs. 16.6 ± 3.2 mL/min per kg, P = 0.456), the VE versus VCO 2 slope (37.8 ± 9.2 vs. 35.9 ± 8.0, P = 0.397), or the peak work-rate (79 ± 29 vs. 84 ± 27W, P = 0.118). Body position had a significant influence on PAP and PAWP during exercise, but no influence on the pulmonary circulation, or peak VO 2 , or VE vs.VCO 2 slope., (© 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.)

Background: Sleep apnea (SA) can cause repeated nocturnal arterial oxygen desaturation and result in acute increase in pulmonary arterial pressure (PAP). The presence of SA is associated with a poor prognosis in patients with chronic left-sided heart failure, but little is known for patients with pulmonary arterial hypertension (PAH). Methods and Results: We enrolled 151 patients with PAH (44±16 years old, male/female=37/114). They were all in the Nice Classification group 1 (idiopathic PAH/associated PAH=52/48%, mean PAP of 46±16 mmHg). They underwent right-heart catheterization and a sleep study with simplified polysomnography. Averaged percutaneous oxygen saturation (SpO 2 ) during sleep was measured and an apnea-hypopnea index >5 was defined as SA. SA was noted in 58 patients (obstructive SA/central SA: 29/29). Over an average follow-up of 1,170±763 days, 32 patients died. By Kaplan-Meier analysis, there was no significant difference in deaths of patients with and without SA (χ 2 =2.82, P=0.093). On the other hand, the mortality in patients with lower averaged SpO 2 was significantly higher than in those with higher averaged SpO 2 (χ 2 =14.7, P<0.001) and that was the only independent variable related to death in multivariate Cox proportional hazards analysis., Conclusions: SA in patients with PAH was not associated with worse prognosis, unlike left ventricular heart failure, but nocturnal hypoxemia was related to poor prognosis.

Background: Excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs) are key mechanisms of pulmonary arterial hypertension (PAH). Despite the multiple combination therapy, a considerable number of patients develop severe pulmonary hypertension (PH) because of the lack of diagnostic biomarker and antiproliferative therapies for PASMCs., Methods: Microarray analyses were used to identify a novel therapeutic target for PAH. In vitro experiments, including lung and serum samples from patients with PAH, cultured PAH-PASMCs, and high-throughput screening of 3336 low-molecular-weight compounds, were used for mechanistic study and exploring a novel therapeutic agent. Five genetically modified mouse strains, including PASMC-specific selenoprotein P (SeP) knockout mice and PH model rats, were used to study the role of SeP and therapeutic capacity of the compounds for the development of PH in vivo., Results: Microarray analysis revealed a 32-fold increase in SeP in PAH-PASMCs compared with control PASMCs. SeP is a widely expressed extracellular protein maintaining cellular metabolism. Immunoreactivity of SeP was enhanced in the thickened media of pulmonary arteries in PAH. Serum SeP levels were also elevated in patients with PH compared with controls, and high serum SeP predicted poor outcome. SeP-knockout mice ( SeP -/- ) exposed to chronic hypoxia showed significantly reduced right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary artery remodeling compared with controls. In contrast, systemic SeP-overexpressing mice showed exacerbation of hypoxia-induced PH. Furthermore, PASMC-specific SeP -/- mice showed reduced hypoxia-induced PH compared with controls, whereas neither liver-specific SeP knockout nor liver-specific SeP-overexpressing mice showed significant differences with controls. Altogether, protein levels of SeP in the lungs were associated with the development of PH. Mechanistic experiments demonstrated that SeP promotes PASMC proliferation and resistance to apoptosis through increased oxidative stress and mitochondrial dysfunction, which were associated with activated hypoxia-inducible factor-1α and dysregulated glutathione metabolism. It is important to note that the high-throughput screening of 3336 compounds identified that sanguinarine, a plant alkaloid with antiproliferative effects, reduced SeP expression and proliferation in PASMCs and ameliorated PH in mice and rats., Conclusions: These results indicate that SeP promotes the development of PH, suggesting that it is a novel biomarker and therapeutic target of the disorder.

Although postcapillary pulmonary hypertension (PH) is an important prognostic factor for patients with heart failure (HF), its pathogenesis remains to be fully elucidated. To elucidate the different roles of Rho-kinase isoforms, ROCK1 and ROCK2, in cardiomyocytes in response to chronic pressure overload, we performed transverse aortic constriction (TAC) in cardiac-specific ROCK1-deficient ( cROCK1 -/- ) and ROCK2-deficient ( cROCK2 -/- ) mice. Cardiomyocyte-specific ROCK1 deficiency promoted pressure-overload-induced cardiac dysfunction and postcapillary PH, whereas cardiomyocyte-specific ROCK2 deficiency showed opposite results. Histological analysis showed that pressure-overload-induced cardiac hypertrophy and fibrosis were enhanced in cROCK1 -/- mice compared with controls, whereas cardiac hypertrophy was attenuated in cROCK2 -/- mice after TAC. Consistently, the levels of oxidative stress were up-regulated in cROCK1 -/- hearts and down-regulated in cROCK2 -/- hearts compared with controls after TAC. Furthermore, cyclophilin A (CyPA) and basigin (Bsg), both of which augment oxidative stress, enhanced cardiac dysfunction and postcapillary PH in cROCK1 -/- mice, whereas their expressions were significantly lower in cROCK2 -/- mice. In clinical studies, plasma levels of CyPA were significantly increased in HF patients and were higher in patients with postcapillary PH compared with those without it. Finally, high-throughput screening demonstrated that celastrol, an antioxidant and antiinflammatory agent, reduced the expressions of CyPA and Bsg in the heart and the lung, ameliorating cardiac dysfunction and postcapillary PH induced by TAC. Thus, by differentially affecting CyPA and Bsg expressions, ROCK1 protects and ROCK2 jeopardizes the heart from pressure-overload HF with postcapillary PH, for which celastrol may be a promising agent., Competing Interests: The authors declare no conflict of interest.

Background: Balloon pulmonary angioplasty (BPA) has been performed for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or residual pulmonary hypertension after pulmonary endarterectomy (PEA). We performed a systematic review to assess the efficacy and safety of BPA, especially compared to medical treatment or PEA., Methods: We reviewed all studies investigating pre- and post-treatment pulmonary hemodynamics, mortality, or complications from three electronic databases (PubMed, Cochrane Library, Japan Medical Abstracts Society) prior to February 2017. From 26 studies retrieved, we selected 13 studies (493 patients): the 10 most recent ones including complete data from each institution, one study of residual pulmonary hypertension, and two studies comparing BPA with medical treatment or PEA., Results: No randomized controlled or prospective controlled studies comparing BPA with medical treatment or PEA were reported. The early mortality of BPA ranged from 0% to 14.3%; lung injury occurred in 7.0% to 31.4% (average sessions, 2.5-6.6). Mean pulmonary arterial pressure decreased from 39.4-56 to 20.9-36 mm Hg, and the 6-min walk distance increased from 191-405 to 359-501 m. The 2-year mortality of 80 patients undergoing BPA was significantly lower compared to 68 patients receiving medical treatment (1.3% vs. 13.2%); the risk ratio was 0.14 (95% confidence interval: 0.03-0.76). No significant difference was observed in the 2-year mortality between BPA (n=97) and PEA (n=63) patients., Conclusions: This systematic review suggests that BPA improves hemodynamics, has acceptable early mortality, and may improve long-term survival compared with medical treatment in inoperable CTEPH patients., (Copyright © 2018 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

Background: The trend of the initial treatment strategy for pulmonary arterial hypertension (PAH) has changed from monotherapies to upfront combination therapies. This study analyzed treatments and outcomes in Japanese patients with PAH, using data from the Japan PH Registry (JAPHR), which is the first organized multicenter registry for PAH in Japan.Methods and Results:We studied 189 consecutive patients (108 treatment-naïve and 81 background therapy patients) with PAH in 8 pulmonary hypertension (PH) centers enrolled from April 2008 to March 2013. We performed retrospective survival analyses and analyzed the association between upfront combination and hemodynamic improvement, adjusting for baseline NYHA classification status. Among the 189 patients, 1-, 2-, and 3-year survival rates were 97.0% (95% CI: 92.1-98.4), 92.6% (95% CI: 87.0-95.9), and 88.2% (95% CI: 81.3-92.7), respectively. In the treatment-naïve cohort, 33% of the patients received upfront combination therapy. In this cohort, 1-, 2-, and 3-year survival rates were 97.6% (95% CI: 90.6-99.4), 97.6% (95% CI: 90.6-99.4), and 95.7% (95% CI: 86.9-98.6), respectively. Patients on upfront combination therapy were 5.27-fold more likely to show hemodynamic improvement at the first follow-up compared with monotherapy (95% CI: 2.68-10.36)., Conclusions: According to JAPHR data, initial upfront combination therapy is associated with improvement in hemodynamic status.

Background: Balloon pulmonary angioplasty (BPA) is an alternative therapy for patients with chronic thromboembolic pulmonary hypertension who are ineligible for pulmonary endarterectomy-the standard therapy. Currently, most reported results of BPA are from relatively small cohorts treated at single centers. The present study evaluated the safety and efficacy of BPA for chronic thromboembolic pulmonary hypertension based on a multicenter registry., Methods and Results: A total of 308 patients (62 men and 246 women; mean age, 61 years) underwent 1408 procedures at 7 institutions in Japan. Data were retrospectively reviewed to evaluate clinical outcome and complications. Hemodynamics were significantly improved in 249 patients in whom BPA was terminated, most often because of improvement in mean pulmonary arterial pressure or symptomatic improvement after 1154 procedures. In 196 patients who underwent follow-up right heart catheterization, improvement of hemodynamic parameters was maintained. Mean pulmonary arterial pressure decreased from 43.2±11.0 to 24.3±6.4 mm Hg after final BPA and 22.5±5.4 mm Hg at follow-up, with significant reduction of concomitant use of pulmonary hypertension-targeted therapy and oxygen supplementation. Complications occurred in 511 (36.3%), including pulmonary injury (17.8%), hemoptysis (14.0%), and pulmonary artery perforation (2.9%). Twelve patients (3.9%) died during follow-up, including 8 patients who died within 30 days after BPA. The leading causes of death were right heart failure, multiorgan failure, and sepsis. Overall survival was 96.8% (95% confidence interval, 93.7%-98.4%) at 1 and 2 years and 94.5% (95% confidence interval, 89.3%-97.3%) at 3 years, respectively, after the initial BPA procedure for all 308 patients., Conclusions: This multicenter registry suggested improved hemodynamic results after BPA. Complication rates were high, but overall survival was comparable with pulmonary endarterectomy. BPA may be an important therapeutic option in patients with chronic thromboembolic pulmonary hypertension., (© 2017 American Heart Association, Inc.)

Background: Selexipag is an orally available prostacyclin receptor (IP receptor) agonist with a non-prostanoid structure. In this open-label Phase II trial, the efficacy and safety of selexipag in Japanese patients with pulmonary arterial hypertension (PAH) is examined.Methods and Results:Selexipag was administered at 200 μg twice daily and titrated up to 1,600 μg by increments of 200 μg in 37 subjects to reach the individual maximum tolerated dose. At 16 weeks, in 33 patients comprising the per-protocol set, the pulmonary vascular resistance (PVR; primary endpoint) decreased from 683.2±237.3 to 560.3±238.7 dyn·s/cm 5 (P<0.0001). For the secondary endpoint, the 6-min walk distance (6MWD) increased from 445.0±102.2 to 459.1±112.8 m (P=0.0324); World Health Organization functional class improved in 4 patients (12.1%), and was maintained in 29 patients (87.9%). A decrease in PVR was also shown in patients treated with selexipag, on top of a phosphodiesterase inhibitor and endothelin receptor antagonist. Most of the commonly reported adverse events were consistent with those reported for other PGI 2 formulations. Thirty-four patients attained the individual maximum tolerated dose (maintenance dose)., Conclusions: The efficacy and tolerability of selexipag in Japanese PAH patients was confirmed by improvement in pulmonary hemodynamics, exercise capacity, symptoms. Selexipag is an efficacious treatment option for Japanese PAH patients. (Trial registration: JAPIC Clinical Trials Information [JapicCTI-111532].).

Background: Pulmonary hypertension (PH), caused by elevated pulmonary vascular resistance, leads to right heart failure and ultimately death. Vitamin D deficiency can predispose individuals to hypertension and left ventricular dysfunction; however, it remains unknown how serum vitamin D level is related to PH and right ventricular (RV) dysfunction., Methods: Serum 25-hydroxyvitamin D [25(OH)D] levels were assessed in PH patients for an association with disease severity. To examine whether vitamin D supplementation could prevent the development of pulmonary vascular remodeling and RV dysfunction in PH, a rat model of PH was fed either normal chow or a high vitamin D diet., Results: The majority (95.1%) of PH patients had 25(OH)D levels in the insufficiency range, which is associated with increased mean pulmonary artery pressure, increased pulmonary vascular resistance, and decreased cardiac output in PH patients. Vitamin D supplementation significantly increased serum 25(OH)D levels and improved survival in PH rats. Interestingly, while the supplemented rats retained the typical increases in medial thickness of the muscular pulmonary arteries and RV systolic pressure, RV cardiomyocyte hypertrophy and B-type natriuretic peptide expression was significantly attenuated., Conclusions: Vitamin D deficiency is frequently seen in patients diagnosed with PH and low serum levels of 25(OH)D are associated with severity of PH and RV dysfunction. Vitamin D supplementation in PH rats improved survival via ameliorating pathological RV hypertrophy. These findings suggest an insufficient intake of vitamin D might potentially accelerate RV dysfunction, leading to a crucial clinical impact of vitamin D supplementation in PH.

Background: The present comparative study with healthy volunteers was conducted to investigate the depressive status and temperament in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Methods and Results:The results of the temperament and personality scale test, and the Quick Inventory of Depressive Symptomatology-Self Report revealed that CTEPH patients have a significantly higher depressive status than healthy volunteers., Conclusions: It may be that CTEPH patients are more likely to have a depressive temperament in origin. It is expected that the relationship between the biological traits of CTEPH (e.g., genetics) and patients' depressive temperament will be elucidated in the future.

Sorafenib is an inhibitor of multi-kinases including tyrosine and serine/threonine kinases. We investigated the efficacy and safety of sorafenib for the treatment of patients with refractory pulmonary arterial hypertension (PAH). Sorafenib was started in 9 patients (7 with idiopathic PAH, 2 with pulmonary veno-occlusive disease) who had severe PAH and right heart failure, in spite of treatment with vasodilators specific for PAH. Sorafenib was started as an add-on therapy at a dose of 50 or 100 mg/day, and increased to 100-400 mg/day. New York Heart Association functional class improved in 8 patients and did not change in 1. Mean pulmonary arterial pressure improved in 6 patients (14-28% decrease) and did not apparently change in 2 (follow-up catheterization was not performed in 1 patient). The main adverse effects of sorafenib were skin reactions on the hands and feet, which appeared in 5 patients. They were tolerable in 4 patients, but discontinuation of sorafenib was needed in only 1 patient. In conclusion, sorafenib had favorable effects to improve symptoms and objective variables in patients with refractory PAH, with tolerable adverse events. Sorafenib is an alternative strategy for patients with refractory PAH., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Rationale: Pulmonary hypertension is a fatal disease; however, its pathogenesis still remains to be elucidated. Thrombin-activatable fibrinolysis inhibitor (TAFI) is synthesized by the liver and inhibits fibrinolysis. Plasma TAFI levels are significantly increased in chronic thromboembolic pulmonary hypertension (CTEPH) patients., Objective: To determine the role of activated TAFI (TAFIa) in the development of CTEPH., Methods and Results: Immunostaining showed that TAFI and its binding partner thrombomodulin (TM) were highly expressed in the pulmonary arteries (PAs) and thrombus in patients with CTEPH. Moreover, plasma levels of TAFIa were increased 10-fold in CTEPH patients compared with controls. In mice, chronic hypoxia caused a 25-fold increase in plasma levels of TAFIa with increased plasma levels of thrombin and TM, which led to thrombus formation in PA, vascular remodeling, and pulmonary hypertension. Consistently, plasma clot lysis time was positively correlated with plasma TAFIa levels in mice. Additionally, overexpression of TAFIa caused organized thrombus with multiple obstruction of PA flow and reduced survival rate under hypoxia in mice. Bone marrow transplantation showed that circulating plasma TAFI from the liver, not in the bone marrow, was activated locally in PA endothelial cells through interactions with thrombin and TM. Mechanistic experiments demonstrated that TAFIa increased PA endothelial permeability, smooth muscle cell proliferation, and monocyte/macrophage activation. Importantly, TAFIa inhibitor and peroxisome proliferator-activated receptor-α agonists significantly reduced TAFIa and ameliorated animal models of pulmonary hypertension in mice and rats., Conclusions: These results indicate that TAFIa could be a novel biomarker and realistic therapeutic target of CTEPH., (© 2017 American Heart Association, Inc.)

Background: Pulmonary artery aneurysm (PAA) occurs in some patients with pulmonary arterial hypertension (PAH). We evaluated the characteristics of cardiac dysfunction in patients with PAH complicated by PAA., Methods: Echocardiography and right-heart catheterization were performed in 130 PAH patients to measure the maximum dimensions of the main pulmonary artery (MPA) trunk and evaluate right ventricular (RV) and left ventricular (LV) function., Results: A diameter of >40mm was defined as PAA in the MPA trunk. The maximum MPA diameter was >40mm in 32 of 130 PAH patients (24.6%: Group PAA). Systolic pulmonary artery pressure (68.0±18.5 vs. 58.9±21.6mm Hg, P=0.0354) and pulmonary capillary wedge pressure (10.8±3.9 vs. 7.7±2.6mm Hg, P<0.0001) were significantly higher in Group PAA than in Group non-PAA. RV end-diastolic area index (19.6±6.8 vs. 14.9±5.1 cm²/m², P<0.0001), and RV fractional area change (32.3±7.8 vs. 37.3±8.8%, P=0.0048) and RV longitudinal strain (-15.4±5.1 vs. -20.4±6.1, P=0.0012) were significantly lower, and E/e' was significantly higher (8.1±2.2 vs. 6.7±1.4, P=0.0002) in Group PAA than in Group non-PAA., Conclusions: In PAH patients with PAA, RV was larger and RV dysfunction was more severe, and LV diastolic dysfunction appeared. It is important to investigate the appearance of PAA and the severity of RV and LV dysfunction in PAH patients with PAA., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Introduction: Percutaneous transluminal pulmonary angioplasty (PTPA) was introduced for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH) in the late 20(th) century, and first attempts in collective patients were made in 2001 with beneficial effects but a moderate amount of complications. It was refined around 2010, and has been recently established as an effective and safe treatment., Areas Covered: The indication was originally inoperable CTEPH with peripheral lesions, but has now widened to symptomatic or hypoxic patients. The lesion is typically a meshwork-like structure of organized thrombi and is sometimes not seen as a stenosis angiographically, necessitating other means of investigation such as measurement of distal pressure. The technique to treat lesions is the same as for coronary angioplasty except in several ways. Expert commentary: The effects of PTPA are comparable to those of surgical endarterectomy, and the complications of reperfusion pulmonary edema and vascular injury are now controlled by several strategies and based on experience.

Rationale: Endothelial AMP-activated protein kinase (AMPK) plays an important role for vascular homeostasis, and its role is impaired by vascular inflammation. However, the role of endothelial AMPK in the pathogenesis of pulmonary arterial hypertension (PAH) remains to be elucidated., Objective: To determine the role of endothelial AMPK in the development of PAH., Methods and Results: Immunostaining showed that endothelial AMPK is downregulated in the pulmonary arteries of patients with PAH and hypoxia mouse model of pulmonary hypertension (PH). To elucidate the role of endothelial AMPK in PH, we used endothelial-specific AMPK-knockout mice (eAMPK(-/-)), which were exposed to hypoxia. Under normoxic condition, eAMPK(-/-) mice showed the normal morphology of pulmonary arteries compared with littermate controls (eAMPK(flox/flox)). In contrast, development of hypoxia-induced PH was accelerated in eAMPK(-/-) mice compared with controls. Furthermore, the exacerbation of PH in eAMPK(-/-) mice was accompanied by reduced endothelial function, upregulation of growth factors, and increased proliferation of pulmonary artery smooth muscle cells. Importantly, conditioned medium from endothelial cells promoted pulmonary artery smooth muscle cell proliferation, which was further enhanced by the treatment with AMPK inhibitor. Serum levels of inflammatory cytokines, including tumor necrosis factor-α and interferon-γ were significantly increased in patients with PAH compared with healthy controls. Consistently, endothelial AMPK and cell proliferation were significantly reduced by the treatment with serum from patients with PAH compared with controls. Importantly, long-term treatment with metformin, an AMPK activator, significantly attenuated hypoxia-induced PH in mice., Conclusions: These results indicate that endothelial AMPK is a novel therapeutic target for the treatment of PAH., (© 2016 American Heart Association, Inc.)