Outcomes of Chronic Thromboembolic Pulmonary Hypertension After Balloon Pulmonary Angioplasty and Pulmonary Endarterectomy.

Background: The contemporary outcome of balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are unclear. Objectives: This study aimed to clarify the characteristics and outcomes of CTEPH patients treated with BPA and PEA in Japan. Methods: Among 1,270 participants enrolled between 2018 and 2023 in the CTEPH AC (Chronic Thromboembolic Pulmonary Hypertension Anticoagulant) registry, a Japanese nationwide CTEPH registry, 369 treatment-naive patients (BPA strategy: n = 313; PEA strategy: n = 56) and 690 on-treatment patients (BPA strategy: n = 561; PEA strategy: n = 129) were classified according to the presence of prior reperfusion therapy. Morbidity and mortality events (all-cause death, rescue mechanical reperfusion therapy, and/or initiation of parenteral pulmonary vasodilators), pulmonary hemodynamics, exercise tolerance, and relevant laboratory test results were evaluated. Results: The BPA strategy was chosen in older patients than the PEA strategy (mean age, BPA vs PEA: 66.5 ± 12.6 years vs 62.5 ± 11.8 years; P = 0.028). Median follow-up period was 615 (Q1-Q3: 311-997) days in treatment-naive patients and 1,136 (Q1-Q3: 684-1,300) days in on-treatment patients. BPA strategy had as acceptable morbidity and mortality as PEA strategy (5-year morbidity and mortality event rate, BPA vs PEA: 10.2% [95% CI: 5.2%-19.5%] vs 16.1% [95% CI: 4.3%-50.6%] in treatment-naive patients; 9.7% [95% CI: 6.7%-13.8%] vs 6.9% [95% CI: 2.7%-17.3%] in on-treatment patients), with greater improvement of renal function; glomerular filtration rate in propensity score-matched population (difference between change: 4.9 [95% CI: 0.5-9.3] mL/min/1.73 m2; P = 0.030). Conclusions: BPA strategy was more frequently chosen in older patients compared with PEA strategy and showed acceptable outcomes for efficacy with greater advantage for improvement in renal function. (Multicenter registry of chronic thromboembolic pulmonary hypertension in Japan; UMIN000033784).

Efficacy, safety, and pharmacokinetics of inhaled treprostinil in Japanese patients with pulmonary hypertension associated with interstitial lung disease.

BACKGROUND: The INCREASE trial, conducted in the United States, showed that inhaled treprostinil improved exercise capacity in pulmonary hypertension associated with interstitial lung disease (PH-ILD). However, hemodynamic and pharmacokinetic measurements were not performed in the trial. The objective of this trial was to evaluate the efficacy on hemodynamics and exercise capacity, safety, and pharmacokinetics (PK) of inhaled treprostinil in Japanese patients with PH-ILD. METHODS: This trial was a multicenter, non-randomized, open-label, single-arm trial of patients with PH-ILD. Inhaled treprostinil was administered at 3 breaths (18 µg)/session four times daily, and the dose was gradually increased to a maximum of 12 breaths (72 µg)/session. The primary endpoints were the change of pulmonary vascular resistance index (PVRI) and peak 6-min walking distance (6MWD) from baseline to week 16. Endpoints also included other efficacy parameters, safety, and PK. RESULTS: Twenty patients received inhaled treprostinil. At week 16, PVRI decreased from baseline by -40.1% (95% CI, -53.1 to -27.2) and peak 6MWD increased by 13.0 m (95% CI, -15.0 to 49.0). The most frequently reported adverse events related with treprostinil were cough, malaise and blood pressure decreased. PK was similar to those in pulmonary arterial hypertension (PAH) patients. CONCLUSIONS: Treatment with inhaled treprostinil using the same dosing regimen as in the INCREASE trial resulted in improvements in hemodynamics and exercise capacity with a favorable tolerability and safety profile in Japanese patients with PH-ILD.

Pulmonary Hypertension With Interstitial Pneumonia: Initial Treatment Effectiveness and Severity in a Japan Registry.

Background: Recent guidelines discourage the use of pulmonary arterial hypertension (PAH)-targeted therapies in patients with pulmonary hypertension (PH) associated with respiratory diseases. Therefore, stratifications of the effectiveness of PAH-targeted therapies are important for this group. Objectives: The authors aimed to identify phenotypes that might benefit from initial PAH-targeted therapies in patients with PH associated with interstitial pneumonia and combined pulmonary fibrosis and emphysema. Methods: We categorized 270 patients with precapillary PH (192 interstitial pneumonia, 78 combined pulmonary fibrosis and emphysema) into severe and mild PH using a pulmonary vascular resistance of 5 WU. We investigated the prognostic factors and compared the prognoses of initial (within 2 months after diagnosis) and noninitial treatment groups, as well as responders (improvements in World Health Organization functional class, pulmonary vascular resistance, and 6-minute walk distance) and nonresponders. Results: Among 239 treatment-naive patients, 46.0% had severe PH, 51.8% had mild ventilatory impairment (VI), and 40.6% received initial treatment. In the severe PH with mild VI subgroup, the initial treatment group had a favorable prognosis compared with the noninitial treatment group. The response rate in this group was significantly higher than the others (48.2% vs 21.8%, ratio 2.21 [95% CI: 1.17-4.16]). In multivariate analysis, initial treatment was a better prognostic factor for severe PH but not for mild PH. Within the severe PH subgroup, responders had a favorable prognosis. Conclusions: This study demonstrated an increased number of responders to initial PAH-targeted therapy, with a favorable prognosis in severe PH cases with mild VI. A survival benefit was not observed in mild PH cases. (Multi-institutional Prospective Registry in Pulmonary Hypertension associated with Respiratory Disease; UMIN000011541).

Artificial intelligence-based model for predicting pulmonary arterial hypertension on chest x-ray images.

BACKGROUND: Pulmonary arterial hypertension is a serious medical condition. However, the condition is often misdiagnosed or a rather long delay occurs from symptom onset to diagnosis, associated with decreased 5-year survival. In this study, we developed and tested a deep-learning algorithm to detect pulmonary arterial hypertension using chest X-ray (CXR) images. METHODS: From the image archive of Chiba University Hospital, 259 CXR images from 145 patients with pulmonary arterial hypertension and 260 CXR images from 260 control patients were identified; of which 418 were used for training and 101 were used for testing. Using the testing dataset for each image, the algorithm outputted a numerical value from 0 to 1 (the probability of the pulmonary arterial hypertension score). The training process employed a binary cross-entropy loss function with stochastic gradient descent optimization (learning rate parameter, α = 0.01). In addition, using the same testing dataset, the algorithm's ability to identify pulmonary arterial hypertension was compared with that of experienced doctors. RESULTS: The area under the curve (AUC) of the receiver operating characteristic curve for the detection ability of the algorithm was 0.988. Using an AUC threshold of 0.69, the sensitivity and specificity of the algorithm were 0.933 and 0.982, respectively. The AUC of the algorithm's detection ability was superior to that of the doctors. CONCLUSION: The CXR image-derived deep-learning algorithm had superior pulmonary arterial hypertension detection capability compared with that of experienced doctors.

Aorta and main pulmonary artery segmentation using stacked U-Net and localization on non-contrast-enhanced computed tomography images.

BACKGROUND: The contact between the aorta, main pulmonary artery (MPA), main pulmonary vein, vena cava (VC), and esophagus affects segmentation of the aorta and MPA in non-contrast-enhanced computed tomography (NCE-CT) images. PURPOSE: A two-stage stacked U-Net and localization of the aorta and MPA were developed for the segmentation of the aorta and MPA in NCE-CT images. METHODS: Normal-dose NCE-CT images of 24 subjects with chronic thromboembolic pulmonary hypertension (CTEPH) and low-dose NCE-CT images of 100 subjects without CTEPH were used in this study. The aorta is in contact with the ascending aorta (AA) and MPA, the AA with the VC, the aortic arch (AR) with the VC and esophagus, and the descending aorta (DA) with the esophagus. These contact surfaces were manually annotated. The contact surfaces were quantified using the contact surface ratio (CSR). Segmentation of the aorta and MPA in NCE-CT images was performed by localization of the aorta and MPA and a two-stage stacked U-Net. Localization was performed by extracting and processing the trachea and main bronchus. The first stage of the stacked U-Net consisted of a 2D U-Net, 2D U-Net with a pre-trained VGG-16 encoder, and 2D attention U-Net. The second stage consisted of a 3D U-Net with four input channels: the CT volume and three segmentation results of the first stage. The model was trained and tested using 10-fold cross-validation. Segmentation of the entire volume was evaluated using the Dice similarity coefficient (DSC). Segmentation of the contact area was also assessed using the mean surface distance (MSD). The statistical analysis of the evaluation underwent a multi-comparison correction. CTEPH and non-CTEPH cases were classified based on the vessel diameters measured from the segmented MPA. RESULTS: For the noncontact surfaces of AA, the MSD of stacked U-Net was 0.31 ± 0.10 mm (p < 0.05) and 0.32 ± 0.13 mm (p < 0.05) for non-CTEPH and CTEPH cases, respectively. For contact surfaces with a CSR of 0.4 or greater in AA, the MSD was 0.52 ± 0.23 mm (p < 0.05), and 0.68 ± 0.29 mm (p > 0.05) for non-CTEPH and CTEPH cases, respectively. MSDs were lower than those of 2D and 3D U-Nets for contact and noncontact surfaces; moreover, MSDs increased slightly with larger CSRs. However, the stacked U-Net achieved MSDs of approximately 1 pixel for a wide contact surface. The area under the receiver operating characteristic curve for CTEPH and non-CTEPH classification using the right main pulmonary artery (RMPA) diameter was 0.97 (95% confidence interval [CI]: 0.94-1.00). CONCLUSIONS: Segmentation of the aorta and MPA on NCE-CT images were affected by vascular and esophageal contact. The application of stacked U-Net and localization techniques for non-CTEPH and CTEPH cases mitigated the impact of contact, suggesting its potential for diagnosing CTEPH.

Adult-onset idiopathic peripheral pulmonary artery stenosis.

BACKGROUND: Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS. METHODS: We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected. RESULTS: 44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively. CONCLUSIONS: In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.

Comparative Treatment Persistence and Adherence to Endothelin Receptor Antagonists Among Patients with Pulmonary Arterial Hypertension in Japan: A Real-World Administrative Claims Database Study.

INTRODUCTION: Real-world data on the comparative effectiveness of endothelin receptor antagonists (ERAs; macitentan, bosentan, ambrisentan) for pulmonary arterial hypertension (PAH), particularly in Asian countries, are scarce. We evaluated the persistence of these ERAs before and after macitentan approval in Japan (2015). METHODS: We used real-world data from the Japanese Medical Data Vision administrative claims database between April 2008 and November 2020. Patients with PAH were identified from the dataset. Persistence to ERA treatment before and after approval of macitentan in Japan was defined as the time between start of the index ERA and treatment discontinuation or death. Propensity score adjustment was applied to minimize confounding effects among treatment groups. RESULTS: In the pre-macitentan approval cohort, 153 and 51 patients received bosentan and ambrisentan, respectively. In the post-macitentan approval cohort, 331, 284, and 91 patients received macitentan, bosentan, and ambrisentan, respectively. Unadjusted median persistence for ambrisentan- and bosentan-treated patients was 19 and 10 months, respectively (adjusted HR 0.87 [95% CI 0.61-1.24]; P = 0.434 [bosentan as reference]). In the post-macitentan approval cohort, unadjusted median persistence was 18 months for macitentan-treated patients versus 6 and 8 months for ambrisentan- and bosentan-treated patients, respectively. Adjusted HRs for ambrisentan and bosentan were 1.48 (95% CI 1.12-1.95; P = 0.006) and 1.63 (95% CI 1.30-2.04; P < 0.001 [macitentan as reference]), respectively. CONCLUSIONS: Real-world data for Japanese patients with PAH showed that persistence was significantly higher for macitentan, versus ambrisentan and bosentan, since its approval.

Clinical significance of lung cross-sectional area measured by computed tomography in chronic thromboembolic pulmonary hypertension: The correlation with pulmonary hemodynamics and the limitations.

The percentage cross-sectional area of the lung under five (%CSA<5) is the percentage of pulmonary vessels with <5 mm2 area relative to the total lung area on computed tomography (CT). The extent that %CSA<5 is related to pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is unclear, as is the effect of pulmonary endarterectomy (PEA) on %CSA<5. Therefore, we aimed to evaluate the clinical significance of %CSA<5 in patients with CTEPH. We studied 98 patients (64 females, mean age 62.5 ± 11.9 years), who underwent CT with %CSA<5 measurement and right heart catheterization (RHC). Patients were classified into groups based on eligibility for PEA. We compared the %CSA<5 with pulmonary hemodynamics measured by RHC in various groups. In 38 patients who underwent PEA, the relationship between %CSA<5 and pulmonary hemodynamics was also evaluated before and after PEA. Significant correlations between %CSA<5 and pulmonary vascular resistance, and compliance, and pulmonary artery pulse pressure were observed in all patients. Pulmonary hemodynamics in the patients who underwent or were eligible for PEA showed a significant correlation with %CSA<5. Additionally, %CSA<5 was significantly lower in the postoperative than in the preoperative group. There was no correlation between changes in %CSA<5 and pulmonary hemodynamics before and after PEA. Furthermore, %CSA<5 did not correlate significantly with prognosis. %CSA<5 may reflect pulmonary hemodynamics in CTEPH with central thrombosis. Furthermore, %CSA<5 was reduced by PEA postoperatively. However, %CSA<5 is not a prognostic indicator, its clinical usefulness in CTEPH patients is limited, and further validation is required.

Partially hydrolyzed guar gum suppresses the progression of pulmonary arterial hypertension in a SU5416/hypoxia rat model.

This study investigated the effects of partially hydrolyzed guar gum (PHGG) on the development of pulmonary arterial hypertension using a SU5416/hypoxia rat model. Our results demonstrated that PHGG treatment suppressed the development of pulmonary hypertension and vascular remodeling with an altered gut microbiota composition.

Long-term outcome of chronic thromboembolic pulmonary hypertension using direct oral anticoagulants and warfarin: a Japanese prospective cohort study.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) requires lifelong anticoagulation. Long-term outcomes of CTEPH under current anticoagulants are unclear. OBJECTIVES: The CTEPH AC registry is a prospective, nationwide cohort study comparing the safety and effectiveness of direct oral anticoagulants (DOACs) and warfarin for CTEPH. PATIENTS/METHODS: Patients with CTEPH, both tre atment-naïve and on treatment, were eligible for the registry. Inclusion criteria were patients aged ≥20 years and those who were diagnosed with CTEPH according to standard guidelines. Exclusion criteria were not specified. The primary efficacy outcome was a composite morbidity, and mortality outcome comprised all-cause death, rescue reperfusion therapy, initiation of parenteral pulmonary vasodilators, and worsened 6-minute walk distance and WHO functional class. The safety outcome was clinically relevant bleeding, including major bleeding. RESULTS: Nine hundred twenty-seven patients on oral anticoagulants at baseline were analyzed: 481 (52%) used DOACs and 446 (48%) used warfarin. The 1-, 2-, and 3-year rates of composite morbidity and mortality outcome were comparable between the DOAC and warfarin groups (2.6%, 3.1%, and 4.2% vs 3.0%, 4.8%, and 5.9%, respectively; P = .52). The 1-, 2-, and 3-year rates of clinically relevant bleeding were significantly lower in DOACs than in the warfarin group (0.8%, 2.4%, and 2.4% vs 2.5%, 4.8%, and 6.4%, respectively; P = 0.036). Multivariable Cox proportional-hazards regression models revealed lower risk of clinically relevant bleeding in the DOAC group than the warfarin group (hazard ratio: 0.35; 95% CI: 0.13-0.91; P = .032). CONCLUSION: This registry demonstrated that under current standard of care, morbidity and mortality events were effectively prevented regardless of anticoagulants, while the clinically relevant bleeding rate was lower when using DOACs compared with warfarin.

Impact of residual pulmonary hypertension on long-term outcomes after pulmonary endarterectomy in the modern era.

Residual pulmonary hypertension (PH) negatively impacts long-term results following pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We sought to reveal whether modern PH therapy with PH-targeted medicine and balloon pulmonary angioplasty (BPA) improved long-term results of residual PH after PEA. Long-term findings of 80 patients who survived PEA between 2011 and 2019 were retrospectively investigated. One month after PEA, 30 patients developed residual PH defined as mean pulmonary artery pressure (mPAP) ≥25 mmHg, of whom 23 were treated by PH-targeted medicine and 9 by BPA. Patients with residual PH acquired considerably better functional status and exercise capacity after PEA, however, exhibited significantly worse survival rates than those without. Eleven patients died during follow-up: 8 patients with residual PH and 3 controls. Among patients with residual PH, the deceased had a significantly lower %decrease in mPAP from 1 month to 1 year following PEA (7.4 [-32.6 to 8.0] % vs. 10.4 [3.7-27.8] %, p = 0.03) and higher mPAP at 1 year following PEA (39.5 [33.25-42.5] vs. 27 [26-34] mmHg, p < 0.01) despite PH-targeted medicine than the survived. No patients passed away from right heart failure, and there was no difference between the groups in CTEPH-related mortality. Modern PH therapy was used to address the majority of residual PH. Long-term survival after PEA was negatively impacted by residual PH, but it appeared that long-term mortality was also correlated with unrelieved residual PH despite PH-targeted medicine. Modern PH therapy may have enhanced functional status and excercise capacity, and averted fatal right heart failure.

Two cases of pulmonary arterial hypertension with specific vascular Мalformations and unique eosinophilic inflammation in carriers of the RNF213 p. Arg4810Lys variant: Case series.

RNF213 p.Arg4810Lys is linked to various vascular diseases, including pulmonary arterial hypertension (PAH); however, its pathogenesis remains unclear. Here, we report the unique features of two cases of severe PAH with this variant: one is the first reported case with stenosis of the thoracic and abdominal aorta, femoral arteries, and subclavian veins. Coexistence of severe and continuous eosinophilic inflammation, which has been suspected to be implicated in the pathogenesis of PAH in previous fundamental studies, was also present in both cases. Further studies are needed to clarify the pathogenetic mechanisms in vascular lesions with this variant.

Modification of pulmonary endarterectomy to prevent neurologic adverse events.

PURPOSE: Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications. METHODS: We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA. RESULTS: PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57 min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure. CONCLUSIONS: NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Mixed venous oxygen tension is a crucial prognostic factor in pulmonary hypertension: a retrospective cohort study.

BACKGROUND: The prognostic value of mixed venous oxygen tension (PvO2) at pulmonary hypertension diagnosis treated with selective pulmonary vasodilators remains unclear. This study sought to investigate the association of PvO2 with long-term prognosis in pulmonary arterial hypertension (PAH) and medically treated chronic thromboembolic pulmonary hypertension (CTEPH) and to identify the distinct mechanisms influencing tissue hypoxia in patients with CTEPH or PAH. METHODS: We retrospectively analyzed data from 138 (age: 50.2 ± 16.6 years, 81.9% women) and 268 (age: 57.4 ± 13.1 years, 72.8% women) patients with PAH and CTEPH, respectively, diagnosed at our institution from 1983 to 2018. We analyzed the survival rates of patients with/without tissue hypoxia (PvO2 < 35 mmHg) and identified their prognostic factors based on the pulmonary hypertension risk stratification guidelines. RESULTS: Survival was significantly poorer in patients with tissue hypoxia than in those without it for PAH (P = 0.001) and CTEPH (P = 0.017) treated with selective pulmonary vasodilators. In patients with PAH, PvO2 more strongly correlated with prognosis than other hemodynamic prognostic factors regardless of selective pulmonary vasodilators usage. PvO2 was the only significant prognostic factor in patients with CTEPH treated with pulmonary hypertension medication. Patients with CTEPH experiencing tissue hypoxia exhibited significantly poorer survival than those in the intervention group (P < 0.001). PvO2 more strongly correlated with the cardiac index (CI) than the alveolar-arterial oxygen gradient (A-aDO2) in PAH; whereas in CTEPH, PvO2 was more strongly correlated with A-aDO2 than with CI. CONCLUSIONS: PvO2 may represent a crucial prognostic factor for pulmonary hypertension. The prognostic impact of tissue hypoxia affects different aspects of PAH and CTEPH, thereby reflecting their distinct pathogenesis.

Altered gut microbiota and its association with inflammation in patients with chronic thromboembolic pulmonary hypertension: a single-center observational study in Japan.

BACKGROUND: The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be associated with chronic inflammation; however, the underlying mechanism remains unclear. Recently, altered gut microbiota were found in patients with pulmonary arterial hypertension (PAH) and in experimental PAH models. The aim of this study was to characterize the gut microbiota in patients with CTEPH and assess the relationship between gut dysbiosis and inflammation in CTEPH. METHODS: In this observational study, fecal samples were collected from 11 patients with CTEPH and 22 healthy participants. The abundance of gut microbiota in these fecal samples was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing. Inflammatory cytokine and endotoxin levels were also assessed in patients with CTEPH and control participants. RESULTS: The levels of serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were elevated in patients with CTEPH. Plasma endotoxin levels were significantly increased in patients with CTEPH (P < 0.001), and were positively correlated with TNF-α, IL-6, IL-8, and MIP-1α levels. The 16S rRNA gene sequencing and the principal coordinate analysis revealed the distinction in the gut microbiota between patients with CTEPH (P < 0.01) and control participants as well as the decreased bacterial alpha-diversity in patients with CTEPH. A random forest analysis for predicting the distinction in gut microbiota revealed an accuracy of 80.3%. CONCLUSION: The composition of the gut microbiota in patients with CTEPH was distinct from that of healthy participants, which may be associated with the elevated inflammatory cytokines and endotoxins in CTEPH.

Selexipag for the treatment of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Treatment options for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) remain limited. Selexipag, an oral selective IP prostacyclin receptor agonist approved for pulmonary arterial hypertension, is a potential treatment option for CTEPH. METHODS: In this multicentre, randomised, double-blind, placebo-controlled study, 78 Japanese patients with inoperable CTEPH or persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and/or balloon pulmonary angioplasty were randomly assigned to receive placebo or selexipag. The primary end-point was the change in pulmonary vascular resistance (PVR) from baseline to week 20. Secondary end-points were changes in other haemodynamic parameters: 6-min walk distance (6MWD), Borg dyspnoea scale score, World Health Organization (WHO) functional class, EuroQol five-dimension five-level tool and N-terminal pro-brain natriuretic peptide. RESULTS: The change in PVR was -98.2±111.3 dyn·s·cm-5 and -4.6±163.6 dyn·s·cm-5 in the selexipag and placebo groups, respectively (mean difference -93.5 dyn·s·cm-5; 95% CI -156.8 to -30.3; p=0.006). The changes in cardiac index (p<0.001) and Borg dyspnoea scale score (p=0.036) were also significantly improved over placebo. 6MWD and WHO functional class were not significantly improved. The common adverse events in the selexipag group corresponded to those generally observed following administration of a prostacyclin analogue. CONCLUSION: Selexipag significantly improved PVR and other haemodynamic variables in patients with CTEPH, although exercise capacity remained unchanged. Further large-scale investigation is necessary to prove the role of selexipag in CTEPH.

Vascular involvement in chronic thromboembolic pulmonary hypertension is associated with spirometry obstructive impairment.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension caused by persistent thromboembolism of the pulmonary arteries. In clinical practice, CTEPH patients often show obstructive ventilatory impairment, even in the absence of a smoking history. Recent reports imply a tendency for CTEPH patients to have a lower FEV1.0; however, the mechanism underlying obstructive impairment remains unknown. METHODS: We retrospectively analyzed CTEPH patients who underwent a pulmonary function test and respiratory impedance test to evaluate their exertional dyspnea during admission for right heart catheterization from January 2000 to December 2019. We excluded patients with a smoking history to rule out the effect of smoking on obstructive impairment. RESULTS: A total of 135 CTEPH patients were analyzed. The median FEV1.0/FVC was 76.0%, %FEV 1.0 had a negative correlation with the mean pulmonary artery pressure and pulmonary vascular resistance and the CT Angiogram (CTA) obstruction score. A multivariate regression analysis revealed that the CTA obstruction score was an independent factor of a lower %FEV1.0. In the 54 patients who underwent pulmonary endarterectomy, %FEV1.0 was improved in some cases and was not in some. Mean PAP largely decreased after PEA in the better %FEV1.0 improved cases, suggesting that vascular involvement in CTEPH could be associated with spirometry obstructive impairment. CONCLUSION: %FEV1.0 had a significant correlation with the CTA obstruction score. Obstructive impairment might have an etiological relationship with vascular involvement. Further investigations could shed new light on the etiology of CTEPH.

Interventricular septal curvature as an additional echocardiographic parameter for evaluating chronic thromboembolic pulmonary hypertension: a single-center retrospective study.

BACKGROUND: Noninvasive estimation of the actual systolic pulmonary artery pressure measured via right-sided heart catheterization (sPAPRHC) is vital for the management of pulmonary hypertension, including chronic thromboembolic pulmonary hypertension (CTEPH). Evaluation related to the interventricular septum (IVS) is generally performed with only visual assessment and has been rarely assessed quantitatively in the field of echocardiography. Thus, this study aimed to investigate the utility of echocardiographic IVS curvature to estimate sPAPRHC in patients with CTEPH. METHODS: Medical records of 72 patients with CTEPH were studied retrospectively. We estimated sPAPRHC using echocardiographic IVS curvature (esPAPcurv) and left ventricular eccentricity index (esPAPLVEI), and compared their ability to predict sPAPRHC with estimated sPAPRHC using tricuspid regurgitant pressure gradient (esPAPTRPG). RESULTS: IVS curvature and LVEI were significantly correlated with sPAPRHC (r = - 0.52 and r = 0.49, respectively). Moreover, the IVS curvature was effective in estimating the sPAPRHC of patients with trivial tricuspid regurgitation (r = - 0.56) and in determining patients with sPAPRHC ≥ 70 mmHg with higher sensitivity (77.0%) compared to those with esPAPTRPG and esPAPLVEI. CONCLUSION: Our results indicate that the echocardiographic IVS curvature could be a useful additional tool for estimating sPAPRHC in CTEPH patients for whom accurate estimation of sPAPRHC using tricuspid regurgitant pressure gradient is challenging.

A case of pulmonary arterial hypertension with V/Q SPECT/CT that showed localized uptake of 99mTc just below the pleura and a unique distribution.

Pulmonary hypertension (PH) is a life-threatening disorder, which originates from various aetiologies. Ventilation-perfusion (V/Q) scanning is commonly used to evaluate the differential diagnosis of PH. Meanwhile, previous studies have shown that single-photon emission computed tomography (SPECT)/CT imaging can provide a more detailed analysis for the assessment of pulmonary blood flow. However, there is insufficient evidence supporting the merits of V/Q SPECT/CT image data in detecting pulmonary vascular disease. Here, we report a case of pulmonary arterial hypertension with localized accumulation and peculiar distribution just below the pleura on V/Q SPECT/CT. Our finding is unique, and it suggests that V/Q SPECT/CT image data might be useful to detect blood flow not only in cases of pulmonary embolism, but also in the more commonly encountered PH.

Characteristics of patients meeting the new definition of pre-capillary pulmonary hypertension (Nice 2018) in a single Japanese pulmonary hypertension center.

BACKGROUND: The 6th World Symposium on Pulmonary Hypertension (Nice 2018) proposed a new definition of pre-capillary pulmonary hypertension (PH) as a condition with mean pulmonary artery pressure (mPAP) > 20 mmHg, pulmonary artery wedge pressure ≤ 15 mmHg, and pulmonary vascular resistance (PVR) ≥ 3 Wood units (WU). The characteristics and prognosis of patients with pre-capillary PH, according to this new definition, is unclear. Therefore, we determined the characteristics and survival of patients with borderline pre-capillary PH. METHODS: We retrospectively enrolled 683 patients who underwent their first right heart catheterization at Chiba University, Japan. Among them, 489 patients met the pre-capillary PH requirement with mPAP ≥ 25 mmHg (conventional pre-capillary PH group), while 22 patients met the borderline pre-capillary PH criteria (borderline pre-capillary PH group). Additionally, 16 patients with a mean PAP of 20-25 and PVR of 2-3 WU were also examined. RESULTS: The borderline pre-capillary PH group comprised 4.3% of the total patients with pre-capillary PH, and the majority was in Group 3 (40.9%) or 4 (45.5%). The survival of the borderline pre-capillary PH group tended to be better than that of the conventional pre-capillary PH group. The prognosis of Group3 PH was the worst among the patients with borderline precapillary PH. There was no significant difference in survival between the borderline pre-capillary PH group with PVR ≥ 3 WU and that with PVR of 2-3 2WU, although none of the patients in the latter group died due to right heart failure. CONCLUSIONS: This is the first study conducted in a PH center in an Asian country to reveal the characteristics of patients with pre-capillary PH, according to the Nice 2018 definition. They comprised 4.3% of the total population with pre-capillary PH, and the majority of the pre-capillary PH cases were in either Group3 or 4. The prognosis may be affected by the patients' underlying diseases. Further prospective studies are needed to determine whether the new definition, including the PVR cut-off, is beneficial in clinical practice.