In 2015, more than 800 papers were published in the field of pulmonary hypertension. A Clinical Year in Review article cannot possibly incorporate all this work and needs to be selective. The recently published European guidelines for the diagnosis and treatment of pulmonary hypertension contain an inclusive summary of all published clinical studies conducted until very recently. Here, we provide an overview of papers published after the finalisation of the guideline. In addition, we summarise recent advances in pulmonary vasculature science. The selection we made from the enormous amount of published work undoubtedly reflects our personal views and may not include all papers with a significant impact in the near or more distant future. The focus of this paper is on the diagnosis of pulmonary arterial hypertension, understanding the success of combination therapy on the right ventricle and scientific breakthroughs.

Group 3 pulmonary hypertension (PH) is a common complication of advanced chronic lung disease. Our hypothesis was that group 3 PH is associated with a more severe baseline presentation and a more severe prognosis compared to group 1 pulmonary arterial hypertension (PAH), chronic thromboembolic PH (group 4), and group 5 PH. We retrospectively analyzed consecutive incident PH patients in a single center between January 2006 and November 2014. Data were acquired from a prospective database. Clinical, functional, and hemodynamic characteristics, as well as survival, were compared between the four groups of precapillary PH. A total of 363 patients were analyzed; 164 patients (45.2%) belonged to group 1 PAH, 109 (30%) to group 3 PH, 65 (17.9%) to group 4 PH, and 25 (6.9%) to group 5 PH. Group 3 patients were predominantly male and were more frequently in New York Heart Association (NYHA) class III/IV. Patients with group 3 and 4 PH were older, had significantly lower 6-min walking distance (6MWD), higher mean pulmonary arterial pressure, higher pulmonary vascular resistance (PVR), and lower cardiac index (CI) than PAH patients. Group 3 and 5 patients had significantly lower total lung capacity (TLC), forced vital capacity (FVC), and FEV1; group 3 patients had the lowest carbon monoxide transfer coefficient values. PH therapy was used in 90.9% of group 3 patients. Univariate analysis of prognostic factors in the overall population showed that age, male gender, NYHA class, groups 3 and 4 PH (vs. PAH), 6MWD, FVC, TLC, carbon monoxide transfer coefficient (KCO), PVR, CI, and venous oxygen saturation were significantly associated with greater mortality. Multivariate analysis showed that age, PH group 4, 6MWD, and KCO but no longer PH group 3 were significantly associated with mortality. Patients with group 3 PH are older, have more severe baseline presentation and lower survival rates than PAH patients in univariate analysis, that seemed to be related to older age.

Pulmonary rehabilitation (PR) is a supervised exercise program for patients with chronic lung disease. Among patients with pulmonary hypertension (PH), PR has been shown to improve both quality of life and exercise capacity. The purpose of this study was to assess the prevalence of PR participation among PH patients, patient perspectives regarding PR, and to identify potential barriers to PR participation. We performed a cross-sectional survey of patients with self-reported PH who attended the Pulmonary Hypertension Association (PHA) conference in June 2022 in Atlanta, Georgia, and patients within the PHA listserv. A total of 429 participants completed the survey and were enrolled in the study. The average age of participants was 61 ± 14 years with 83% of participants identifying as female, 51% of patients self-reported as having group 1 PH. Among patients who completed the survey, 41% had previously attended a PR program. Of those who had completed a PR program, 83% reported being satisfied or very satisfied with the program and 86% reported that they would recommend PR to other PH patients. After completion of a PR program, 76% of patients reported an improvement in their quality of life and 88% reported improvement in exercise capacity. Among the patients who had not previously participated in PR (n = 254), 63% reported an interest in participation while 64% cited a lack of discussion from their treatment team as the primary reason for the lack of PR participation. Limitations of the study include sampling and response bias. According to this cross-sectional survey, the majority of PH patients who have participated in PR report improvement in both quality of life and exercise capacity and would recommend PR to other PH patients. The majority of PH patients who have not participated in PR were interested in participation and cited a lack of discussion with their treatment team as one of the primary reasons for the lack of participation. PR is associated with self-reported improvements in quality of life and exercise capacity but remains underutilized among patients with PH.

The accumulation of iron-dependent lipid peroxides induces ferroptosis, a nonapoptotic form of cell death that integrates metabolic derangements with oxidative stress 1 . Multiple organelles regulate ferroptosis, but the mitochondria may be the most important organelle as mitochondria both initiate and propagate ferroptosis 1 . Altered ferroptosis homeostasis is linked to multiple diseases including cancer, sepsis, cardiovascular diseases, and aging. In the cardiovascular realm, ferroptosis underlies mitochondrial dysfunction and impaired cardiac contractility due to both ischemic and non-ischemic insults 1 . Additionally, ferroptosis induces endothelial cell dysfunction and accelerates atherosclerosis development in mice 2 . At present, the role of ferroptosis in the pulmonary vasculature is relatively unexplored. However, pulmonary arterial endothelial cell dysfunction, characterized by disrupted mitochondrial function and impaired iron and lipid metabolism 4 , contributes to pulmonary hypertension (PH) pathobiology. These molecular phenotypes provide a plausible link between pulmonary vascular disease and ferroptosis. Additionally, ferroptosis inhibition, starting before administration of monocrotaline (MCT), blunts PH severity in rats 3 , but the preventative approach used in this study may limit its translatability. Here, we employed a drug intervention in translational rodent studies, quantitative lung proteomics, and a human genetic association study to evaluate how ferroptosis modulates PH severity.

Chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) are two forms of pulmonary hypertension (PH) characterized by obstructive vasculopathy. Endothelial dysfunction along with metabolic changes towards increased glycolysis are important in PAH pathophysiology. Less is known about such abnormalities in endothelial cells (ECs) from CTEPH patients. This study provides a systematic metabolic comparison of ECs derived from CTEPH and PAH patients. Metabolic gene expression was studied using qPCR in cultured CTEPH-EC and PAH-EC. Western blot analyses were done for HK2, LDHA, PDHA1, PDK and G6PD. Basal viability of CTEPH-EC and PAH-EC with the incubation with metabolic inhibitors was measured using colorimetric viability assays. Human pulmonary artery endothelial cells (HPAEC) were used as healthy controls. Whereas PAH-EC showed significant higher mRNA levels of GLUT1, HK2, LDHA, PDHA1 and GLUD1 metabolic enzymes compared to HPAEC, CTEPH-EC did not. Oxidative phosphorylation associated proteins had an increased expression in PAH-EC compared to CTEPH-EC and HPAEC. PAH-EC, CTEPH-EC and HPAEC presented similar HOXD macrovascular gene expression. Metabolic inhibitors showed a dose-dependent reduction in viability in all three groups, predominantly in PAH-EC. A different metabolic profile is present in CTEPH-EC compared to PAH-EC and suggests differences in molecular mechanisms important in the disease pathology and treatment.

Despite recent advances, the prognosis of pulmonary hypertension (PH) remains poor. While the initial insult in PH implicates the pulmonary vasculature, the functional state, exercise capacity, and survival of such patients are closely linked to right ventricular (RV) function. In the current study, we sought to investigate the effects of maximum incremental exercise on the matching of RV contractility and afterload (i.e. right ventricular-pulmonary arterial [RV-PA] coupling) in patients with exercise PH (ePH) and pulmonary arterial hypertension (PAH). End-systolic elastance (Ees), pulmonary arterial elastance (Ea), and RV-PA coupling (Ees/Ea) were determined using single-beat pressure-volume loop analysis in 40 patients that underwent maximum invasive cardiopulmonary exercise testing. Eleven patients had ePH, nine had PAH, and 20 were age-matched controls. During exercise, the impaired exertional contractile reserve in PAH was associated with blunted stroke volume index (SVI) augmentation and reduced peak oxygen consumption (peak VO2 %predicted). Compared to PAH, ePH demonstrated increased RV contractility in response to increasing RV afterload during exercise; however, this was insufficient and resulted in reduced peak RV-PA coupling. The dynamic RV-PA uncoupling in ePH was associated with similarly blunted SVI augmentation and peak VO2 as PAH. In conclusion, dynamic rest-to-peak exercise RV-PA uncoupling during maximum exercise blunts SV increase and reduces exercise capacity in exercise PH and PAH. In ePH, the insufficient increase in RV contractility to compensate for increasing RV afterload during maximum exercise leads to deterioration of RV-PA coupling. These data provide evidence that even in the early stages of PH, RV function is compromised.

Pulmonary hypertension (PH) is a prevalent disease of the pulmonary vasculature that is characterised by considerable morbidity and mortality. Substantial efforts have been made in recent years to improve disease recognition, diagnosis and management, and this is reflected in current guidelines. The haemodynamic definition of PH has been revised and a definition for exercise PH has been provided. Risk stratification has been refined and the importance of comorbidities and phenotyping have been highlighted. These changes provide an opportunity to potentially identify pulmonary vascular disease at an earlier stage and to enhance patient-centred, goal-orientated treatment decisions. A promising fourth treatment pathway for pulmonary arterial hypertension and potential targeted therapies for group 3 PH are on the horizon, concepts which seemed inconceivable only a few years ago. Beyond medication, there is a greater appreciation for the importance of supervised training in stable PH and the possible role of interventional therapies in select cases. The landscape of PH is changing and it is characterised by progress, innovation and opportunities. In this article, we highlight some of the new trends in PH, with a specific focus on the revised European Society of Cardiology/European Respiratory Society 2022 guidelines for the diagnosis and management of PH.

Noninvasive estimation of systolic pulmonary artery pressure (SPAP) during exercise stress echocardiography (ESE) is recommended for pulmonary hemodynamics evaluation but remains flow-dependent. Our aim was to assess the feasibility of pulmonary vascular reserve index (PVRI) estimation during ESE combining SPAP with cardiac output (CO) or exercise-time and compare its value in three group of patients: with invasively confirmed pulmonary hypertension (PH), at risk of PH development (PH risk) mainly with systemic sclerosis and in controls (C) without clinical risk factors for PH, age-matched with PH risk patients. We performed semisupine ESE in 171 subjects: 31 PH, 61 PH at risk and 50 controls as well as in 29 young, healthy normals. Rest and stress assessment included: tricuspid regurgitant flow velocity (TRV), pulmonary acceleration time (ACT), CO (Doppler-estimated). SPAP was calculated from TRV or ACT when TRV was not available. We estimated PVRI based on CO (peak CO/SPAP*0.1) or exercise-time (ESE time/SPAP*0.1). During stress, TRV was measurable in 44% patients ACT in 77%, either one in 95%. PVRI was feasible in 65% subjects with CO and 95% with exercise-time (p < 0.0001). PVRI was lower in PH compared to controls both for CO-based PVRI (group 1 = 1.0 ± 0.95 vs group 3 = 4.28 ± 2.3, p < 0.0001) or time-based PVRI estimation (0.66 ± 0.39 vs 3.95 ± 2.26, p < 0.0001). The proposed criteria for PH detection were for CO-based PVRI ≤ 1.29 and ESE-time based PVRI ≤ 1.0 and for PH risk ≤ 1.9 and ≤ 1.7 respectively. Noninvasive estimation of PVRI can be obtained in near all patients during ESE, without contrast administration, integrating TRV with ACT for SPAP assessment and using exercise time as a proxy of CO. These indices allow for comparison of pulmonary vascular dynamics in patients with varied exercise tolerance and clinical status.

Development of pulmonary hypertension (PH) in patients with left side heart disease (LHD) is a predictor of poor prognosis. The use of pulmonary vasodilators in PH associated with LHD (PH-LHD) is controversial. In this study, we describe the practice patterns regarding the use of pulmonary vasodilators in PH-LHD among a group of international pediatric PH specialists. A survey was distributed to the members of three pediatric PH networks: PPHNet, PVRI, and REHIPED. The survey queried participants on the rationale, indications, and contraindications of the use of pulmonary vasodilators in children with PH-LHD. Forty-seven PH specialists from 39 PH centers completed the survey. Participants included PH specialists from North America (57%), South America (15%), and Europe (19%). The majority of participants (74%) recommended the use of pulmonary vasodilators only in patients with combined pre-capillary and post-capillary pulmonary hypertension. Participants required the presence of clinical symptoms or signs of heart failure (68%) or right ventricular dysfunction by echocardiography (51%) in order to recommend pulmonary vasodilator therapy. There was no agreement regarding hemodynamic criteria used to recommend pulmonary vasodilators or the etiologies of LHD considered contraindications for using pulmonary vasodilators to manage PH-LHD. Of the available PH-targeted drugs, most participants preferred the use of phosphodiesterase-5-inhibitors for this indication. In conclusion, the practice of recommending pulmonary vasodilators in PH-LHD is highly variable among international pediatric PH specialists. Most specialists of those surveyed (57% in North America) would consider the use of pulmonary vasodilators in PH-LHD only if pre-capillary pulmonary hypertension and right ventricular dysfunction are present.

No abstract available

The high morbidity and mortality rate of pulmonary arterial hypertension (PAH) is partially explained by metabolic deregulation. The present study complements our previous publication in "Genes" by identifying significant increases of the glucose transporter solute carrier family 2 (Slc2a1), beta nerve growth factor (Ngf), and nuclear factor erythroid-derived 2-like 2 (Nfe2l2) in three standard PAH rat models. PAH was induced by subjecting the animals to hypoxia (HO), or by injecting with monocrotaline in either normal (CM) or hypoxic (HM) atmospheric conditions. The Western blot and double immunofluorescent experiments were complemented with novel analyses of previously published transcriptomic datasets of the animal lungs from the perspective of the Genomic Fabric Paradigm. We found substantial remodeling of the citrate cycle, pyruvate metabolism, glycolysis/gluconeogenesis, and fructose and mannose pathways. According to the transcriptomic distance, glycolysis/gluconeogenesis was the most affected functional pathway in all three PAH models. PAH decoupled the coordinated expression of many metabolic genes, and replaced phosphomannomutase 2 (Pmm2) with phosphomannomutase 1 (Pmm1) in the center of the fructose and mannose metabolism. We also found significant regulation of key genes involved in PAH channelopathies. In conclusion, our data show that metabolic dysregulation is a major PAH pathogenic factor.

Patient registries are a valuable tool in the research of rare conditions such as pulmonary hypertension (PH). We report comprehensive hemodynamic and survival data of 174 patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), included in the prospective Latvian PH registry over a period of > 9 years. In total, 130 adult PAH patients (75%) and 44 adult CTEPH patients (25%) were enrolled. The median follow-up period was 33 months for PAH and 18 months for CTEPH, P = 0.001. Latvian CTEPH patients had significantly higher plasma levels of B-type natriuretic peptide, higher pulmonary vascular resistance, and lower cardiac index than Latvian PAH patients. Calculated incidence of PAH and CTEPH in Latvia in 2016 was 13.7 and 5.1 cases per million inhabitants, calculated prevalence was 45.7 and 15.7 cases per million inhabitants, respectively. Survival rates at one, three, and five years for PAH patients was 88.0%, 73.3%, and 58.1%, and 83.8%, 59.0%, and 44.2% for CTEPH patients, respectively. We compared our study results with data from European adult PH registries. Latvian PAH patients had the fourth lowest and CTEPH patients the lowest one-year survival rate among European adult PH registries. As most PH registries in Europe are small, yet with equivalent patient inclusion criteria, it would be desirable to combine these registries to produce more reliable and high-quality study results.

No abstract available

Exercise pulmonary hypertension (ePH) is an underappreciated form of exertional limitation. Despite normal resting pulmonary artery pressures, patients with ePH demonstrate early pulmonary vascular changes with reduced pulmonary arterial compliance (PAC) and vascular distensibility (α). Recent data suggest that targeted vasodilator therapy may improve hemodynamics in ePH, but it is not well-known whether such medications alter pulmonary vascular distensibility. Thus, we sought to evaluate if vasodilator therapy improved α a marker of early pulmonary vascular disease in ePH. Ten patients performed supine exercise right heart catheterization (exRHC) with bicycle ergometer to peak exercise. Patients diagnosed with ePH were treated with pulmonary vasodilators. A repeat symptom-limited exercise RHC was performed at least six months after therapy. Patients with ePH had evidence of early pulmonary vascular disease, as baseline PAC and α were reduced. After pulmonary vasodilator therapy, a number of peak exercise hemodynamics statistically improved, including a decrease of total pulmonary resistance and pulmonary vascular resistance, while cardiac output increased. Importantly, vasodilator therapy partially reversed the pathogenic decreases of α at the time of repeat exRHC. Pulmonary vascular distensibility, α, a marker of early pulmonary vascular disease, improves in ePH after therapy with pulmonary vasodilators.

To re-assess cardiovascular metrics on computed tomography pulmonary angiography (CTPA) in predicting pulmonary hypertension (PH) under the 2022 ESC/ERS guidelines.

Hypoxic pulmonary vascular remodeling is a pathological feature of pulmonary hypertension (PH). Our results showed that centromere-associated protein E (CENPE) expression in PH patients and hypoxia-induced PH rats was significantly higher than that in normal controls. In addition, CENPE deficiency significantly inhibited the development of pulmonary vascular remodeling and right ventricular hypertrophy. Moreover, knocking out CENPE effectively inhibited the proliferation and induced the apoptosis of primary pulmonary artery smooth muscle cells (PASMCs) in vivo. Furthermore, CENPE silencing by small interference significantly inhibited abnormal proliferation, apoptosis resistance, migration, and cell cycle arrest in hypoxia-induced PASMCs. Interestingly, we found that CENPE might exert its biological effect by targeting the transcription of CDK1 proteins.

Compared to idiopathic pulmonary arterial hypertension (IPAH), patients with portopulmonary hypertension (POPH) have worse survival. Health disparities may contribute to these differences but have not been studied. We sought to compare socioeconomic factors in patients with POPH and IPAH and to determine whether socioeconomic status and/or POPH diagnosis were associated with treatment and health-care utilization. We performed a cross-sectional study of adults enrolled in the Pulmonary Hypertension Association Registry. Patients with IPAH (n = 344) and POPH (n = 57) were compared. Compared with IPAH, patients with POPH were less likely to be college graduates (19.6% vs. 34.9%, p = 0.02) and more likely to be unemployed (54.7% vs. 30.5%, p < 0.001) and have an annual household income below poverty level (45.7% vs. 19.0%, p < 0.001). Patients with POPH had similar functional class, quality of life, 6-min walk distance, and mean pulmonary arterial pressure with a higher cardiac index. Compared with IPAH, patients with POPH were less likely to receive combination therapy (46.4% vs. 62.2%, p = 0.03) and endothelin receptor antagonists (28.6% vs. 55.1%, p < 0.001) at enrollment with similar treatment at follow-up. Patients with POPH had more emergency department visits (1.7 ± 2.1 vs. 0.9 ± 1.2, p = 0.009) and hospitalizations in the six months preceding enrollment (1.5 ± 2.1 vs. 0.8 ± 1.1, p = 0.02). Both POPH diagnosis and lower education level were independently associated with a higher number of emergency department visits. Compared to IPAH, patients with POPH have lower socioeconomic status, are less likely to receive initial combination therapy and endothelin receptor antagonists but have similar treatment at follow-up, and have increased health-care utilization.

Pulmonary hypertension (PH) is the hemodynamic manifestation of various pathological processes that result in elevated pulmonary artery pressures (PAP). The National Institutes of Health Registry defined pulmonary arterial hypertension as the mean PAP of more than 25 mm Hg with a pulmonary capillary wedge pressure or left atrial pressure equal to or less than 15 mm Hg. This definition remains the currently accepted definition of PH that is used to define PH related to multiple clinical conditions including chronic obstructive pulmonary disease (COPD). The estimated US prevalence of COPD by the National Health Survey in 2002 in people aged >25 was 12.1 million. There is a lack of large population-based studies in COPD to document the correct prevalence of PH and outcome. The major cause of PH in COPD is hypoxemia leading to vascular remodeling. Echocardiogram is the initial screening tool of choice for PH. This simple noninvasive test can provide an estimate of right ventricular systolic and right atrial pressures. Right heart catheterization remains the gold standard to diagnose PH. It provides accurate measurement of mean PAP and pulmonary capillary wedge pressure. Oxygen therapy remains the cornerstone therapeutic for hypoxemia in COPD patients. Anecdotal reports suggest utility of PDE5-inhibitors and prostacyclin to treat COPD-related PH. Large randomized clinical trials are needed before the use of these drugs can be recommended.

The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is unknown. Histopathologic studies revealed that pulmonary vasculature lesions similar to idiopathic pulmonary arterial hypertension (PAH) existed in CTEPH patients as well. It's well-known that genetic predisposition plays an important role in the mechanism of PAH. So we hypothesized that PAH-causing gene mutation might exist in some CTEPH patients and act as a background to facilitate the development of CTEPH. In this study, we analyzed 7 PAH-causing genes including BMPR2, ACVRL1, ENG, SMAD9, CAV1, KCNK3, and CBLN2 in 49 CTEPH patients and 17 patients recovered from pulmonary embolism (PE) but without pulmonary hypertension(PH). The results showed that the nonsynonymous mutation rate in CTEPH patients is significantly higher than that in PE without PH patients (25 out of 49 (51%) CTEPH patients vs. 3 out of 17 PE without PH patients (18%); p = 0.022). Four CTEPH patients had the same point mutation in ACVRL1 exon 10 (c.1450C>G), a mutation approved to be associated with PH in a previous study. In addition, we identified two CTEPH associated SNPs (rs3739817 and rs55805125). Our results suggest that PAH-causing gene mutation might play an important role in the development of CTEPH.

To determine whether global reduction of CD68 (cluster of differentiation) macrophages impacts the development of experimental pulmonary arterial hypertension (PAH) and whether this reduction affects the balance of pro- and anti-inflammatory macrophages within the lung. Additionally, to determine whether there is evidence of an altered macrophage polarization in patients with PAH. Approach and Results: Macrophage reduction was induced in mice via doxycycline-induced CD68-driven cytotoxic diphtheria toxin A chain expression (macrophage low [MacLow] mice). Chimeric mice were generated using bone marrow transplant. Mice were phenotyped for PAH by echocardiography and closed chest cardiac catheterization. Murine macrophage phenotyping was performed on lungs, bone marrow-derived macrophages, and alveolar macrophages using immunohistochemical and flow cytometry. Monocyte-derived macrophages were isolated from PAH patients and healthy volunteers and polarization capacity assessed morphologically and by flow cytometry. After 6 weeks of macrophage depletion, male but not female MacLow mice developed PAH. Chimeric mice demonstrated a requirement for both MacLow bone marrow and MacLow recipient mice to cause PAH. Immunohistochemical analysis of lung sections demonstrated imbalance in M1/M2 ratio in male MacLow mice only, suggesting that this imbalance may drive the PAH phenotype. M1/M2 imbalance was also seen in male MacLow bone marrow-derived macrophages and PAH patient monocyte-derived macrophages following stimulation with doxycycline and IL (interleukin)-4, respectively. Furthermore, MacLow-derived alveolar macrophages showed characteristic differences in terms of their polarization and expression of diphtheria toxin A chain following stimulation with doxycycline.