Sleep-disordered breathing and nocturnal hypoxemia in chronic thromboembolic pulmonary disease.

BACKGROUND AND AIMS: Sleep-disordered breathing (SDB) and nocturnal hypoxemia were known to be present in patients with chronic thromboembolic pulmonary hypertension (CTEPH), but the difference between SDB and nocturnal hypoxemia in patients who have chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) at rest remains unknown. METHODS: Patients who had CTEPH (n = 80) or CTEPD without PH (n = 40) and who had undergone sleep studies from July 2020 to October 2022 at Shanghai Pulmonary Hospital were enrolled. Nocturnal mean SpO2 (Mean SpO2) <90% was defined as nocturnal hypoxemia, and the percentage of time with a saturation below 90% (T90%) exceeding 10% was used to evaluate the severity of nocturnal hypoxemia. Logistic and linear regression analyses were performed to investigate the difference and potential predictor of SDB or nocturnal hypoxemia between CTEPH and CTEPD without PH. RESULTS: SDB was similarly prevalent in CTEPH and CTEPD without PH (P = 0.104), both characterised by obstructive sleep apnoea (OSA). Twenty-two patients with CTEPH were diagnosed with nocturnal hypoxemia, whereas only three were diagnosed with CTEPD without PH (P = 0.021). T90% was positively associated with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance in patients with CTEPH and CTEPD without PH (P < 0.001); T90% was also negatively related to cardiac output in these patients. Single-breath carbon monoxide diffusing capacity, sex and mPAP were all correlated with nocturnal hypoxemia in CTEPH and CTEPD without PH (all P < 0.05). CONCLUSION: Nocturnal hypoxemia was worse in CTEPD with PH; T90%, but not SDB, was independently correlated with the hemodynamics in CTEPD with or without PH.

Peak oxygen uptake is a strong prognostic predictor for pulmonary hypertension due to left heart disease.

BACKGROUND: Pulmonary hypertension in left heart disease (PH-LHD), which includes combined post- and precapillary PH (Cpc-PH) and isolated postcapillary PH (Ipc-PH), differs significantly in prognosis. We aimed to assess whether cardiopulmonary exercise testing (CPET) predicts the long-term survival of patients with PH-LHD. METHODS: A single-center observational cohort enrolled 89 patients with PH-LHD who had undergone right heart catherization and CPET (mean pulmonary arterial pressure > 20 mm Hg and pulmonary artery wedge pressure ≥ 15 mm Hg) between 2013 and 2021. A receiver operating characteristic curve was plotted to determine the cutoff value of all-cause death. Survival was estimated using the Kaplan-Meier method and analyzed using the log-rank test. The Cox proportional hazards model was performed to determine the association between CPET and all-cause death. RESULTS: Seventeen patients died within a mean of 2.2 ± 1.3 years. Compared with survivors, nonsurvivors displayed a significantly worse 6-min walk distance, workload, exercise time and peak oxygen consumption (VO2)/kg with a trend of a lower oxygen uptake efficiency slope (OUES) adjusted by Bonferroni's correction. Multivariate Cox regression revealed that the peak VO2/kg was significantly associated with all-cause death after adjusting for Cpc-PH/Ipc-PH. Compared with Cpc-PH patients with a peak VO2/kg ≥ 10.7 ml kg-1 min-1, Ipc-PH patients with a peak VO2/kg < 10.7 ml kg-1 min-1 had a worse survival (P < 0.001). CONCLUSIONS: The peak VO2/kg is independently associated with all-cause death in patients with PH-LHD. The peak VO2/kg can also be analyzed together with Cpc-PH/Ipc-PH to better indicate the prognosis of patients with PH-LHD.

Characteristics of exercise capacity in female systemic lupus erythematosus associated pulmonary arterial hypertension patients.

BACKGROUND: To study the oxygen uptake efficiency and determine usefulness of submaximal parameters of oxygen uptake in systemic lupus erythematosus associated pulmonary arterial hypertension (SLE PAH) on performing a cardiopulmonary exercise test (CPET). METHODS: CPET was performed in 21 SLE PAH patients, equal number of idiopathic pulmonary arterial hypertension (IPAH) patients and controls. Peak VO2, anaerobic threshold (AT), oxygen uptake efficiency slope (OUES) and oxygen uptake efficiency plateau (OUEP) and other CPET parameters were examined. All subjects had pulmonary function test (PFT) at rest, which included FEV1, FVC, FEV1/FVC, DLCO measurements. Right heart catheterization (RHC) was also done in SLE PAH and IPAH patients. CPET parameters were compared with RHC parameters to determine potential correlations. RESULTS: Peak VO2, PETCO2 and peak O2 pulse were lower in SLE PAH than IPAH and controls with OUE being lower during all stages of exercise in SLE PAH. DLCO and FVC values were significantly lower in SLE PAH (p < 0.05). Peak O2 pulse and VO2@AT in SLE PAH and IPAH was low (p < 0.05) and significant difference between SLE PAH and IPAH was seen (p < 0.05). PVR correlated with the lowest VE/VCO2, O2 pulse, peak PETCO2 and OUE in SLE PAH patients (all p < 0.05). CONCLUSIONS: SLE PAH patients have cardiopulmonary exercise limitation with reduced oxygen uptake efficiency. VO2@ at AT, peak O2 pulse and O2 pulse at AT were significantly reduced (p < 0.05). Key CPET parameters correlated with elevated pulmonary vascular resistance (PVR). Submaximal parameters of oxygen uptake are equally useful in SLE PAH.

Profiling nitric oxide metabolites in patients with idiopathic pulmonary arterial hypertension.

Intact nitric oxide (NO) signalling is critical to maintaining appropriate pulmonary vascular tone. NO bioavailability is reduced in patients with pulmonary arterial hypertension. This study aimed to examine the impact of NO plasma metabolites (NOx) relative to haemodynamic dysfunction and mortality in patients with idiopathic pulmonary arterial hypertension (IPAH).A total of 104 consecutive adult IPAH patients who had undergone genetic counselling when first diagnosed were enrolled in this prospective study.The median concentration of NOx (µmol·L-1) was significantly lower in IPAH patients compared with healthy subjects, and was decreased further in 19 carriers of the bone morphogenetic protein-receptor type-2 (BMPR2) mutation compared to non-carriers. Reduced concentrations of NOx were correlated with mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR) and cardiac output. Compared with higher baseline NOx concentrations, patients with a NOx concentration of ≤10 µmol·L-1 had a markedly worse survival. After adjustment for clinical features, a BMPR2 mutation and haemodynamics, a lower NOx level remained an increased risk of mortality.Patients with IPAH had lower levels of plasma NOx, which correlated inversely with mPAP, PVR and survival. Plasma NOx may be an important biomarker and prognostic indicator, suggesting that reduced NO synthesis contributes to the pathogenesis of IPAH.

Pulmonary vascular resistance predicts the mortality in patients with bronchiectasis-associated pulmonary hypertension.

OBJECTIVE: Pulmonary hypertension is a severe complication of bronchiectasis, characterized by elevated pulmonary vascular resistance (PVR) and subsequent right heart failure. The association between PVR and mortality in bronchiectasis-associated pulmonary hypertension has not been investigated previously. METHODS: In the present study, a retrospective analysis was conducted on 139 consecutive patients diagnosed with bronchiectasis-associated pulmonary hypertension based on right heart catheterization, enrolled between January 2010 and June 2023. Baseline clinical characteristics and hemodynamic assessment were analyzed. The survival time for each patient was calculated in months from the date of diagnosis until the date of death or, if the patient was still alive, until their last visit. RESULTS: Patients with bronchiectasis-associated pulmonary hypertension exhibited estimated survival rates of 89.5, 70, and 52.9 at 1-year, 3-year, and 5-year intervals respectively, with a median survival time of 67 months. Multivariable Cox regression analysis revealed that increased age [(adjusted hazard ratio per year 1.042, 95% confidence interval (CI) 1.008-1.076, P = 0.015] and elevated PVR (adjusted HR per 1 Wood Units 1.115, 95% CI 1.015-1.224, P = 0.023) were associated with an increased risk of all-cause mortality. In contrast, higher BMI was associated with a decreased risk of all-cause death (adjusted hazard ratio per 1 kg/m2 0.915, 95% CI 0.856-0.979, P = 0.009). Receiver-operating characteristic analyses identified a cutoff value for PVR at 4 Wood Units as predictive for all-cause death within 3 years [area under the curve (AUC) = 0.624; specificity= 87.5%; sensitivity= 35.8%; P < 0.05]. Patients with a PVR greater than 4 Wood Units had a significantly higher risk of all-cause death compared with those with 4 Wood Units or less (adjusted hazard ratio 2.392; 95% CI 1.316-4.349; P = 0.019). Notably, there were no significant differences in age, sex, BMI, WHO functional class, 6-min walk distance, and NT-proBNP levels at baseline between patients categorized as having 4 Wood Units or less or greater than 4 Wood Units for PVR. CONCLUSION: Based on these data, PVR could serve as a discriminative marker for distinguishing between nonsevere pulmonary hypertension (PVR ≤ 4 Wood Units) and severe pulmonary hypertension (PVR > 4 Wood Units). The utilization of a PVR cutoff value of 4.0 Wood Units provides enhanced prognostic capabilities for predicting mortality.

Evaluating the efficacy and safety of oral triple sequential combination therapy for treating patients with pulmonary arterial hypertension: A multicenter retrospective study.

This study aimed to evaluate the effectiveness and safety of an oral sequential triple combination therapy with selexipag after dual combination therapy with endothelin receptor antagonist (ERA) and phosphodiesterase-5 inhibitor (PDE5I)/riociguat in pulmonary arterial hypertension (PAH) patients. A total of 192 PAH patients from 10 centers had received oral sequential selexipag therapy after being on dual-combination therapy with ERA and PDE5i/riociguat for a minimum of 3 months. Clinical data were collected at baseline and after 6 months of treatment. The study analyzed the event-free survival at 6 months and all-cause death over 2 years. At baseline, the distribution of patients among the risk groups was as follows: 22 in the low-risk group, 35 in the intermediate-low-risk group, 91 in the intermediate-high-risk group, and 44 in the high-risk group. After 6 months of treatment, the oral sequential triple combination therapy resulted in reduced NT-proBNP levels (media from 1604 to 678 pg/mL), a decline in the percentage of WHO-FC III/IV (from 79.2% to 60.4%), an increased in the 6MWD (from 325 ± 147 to 378 ± 143 m) and a rise in the percentage of patients with three low-risk criteria (from 5.7% to 13.5%). Among the low-risk group, there was an improvement in the right heart remodeling, marked by a decrease in right atrium area and eccentricity index. The intermediate-low-risk group exhibited significant enhancements in WHO-FC and tricuspid annular plane systolic excursion. For those in the intermediate-high and high-risk groups, there were marked improvements in activity tolerance, as reflected by WHO-FC and 6MWD. The event-free survival rate at 6 months stood at 88%. Over the long-term follow-up, the survival rates at 1 and 2 years were 86.5% and 86.0%, respectively. In conclusion, the oral sequential triple combination therapy enhanced both exercise capacity and cardiac remodeling across PAH patients of different risk stratifications.

[Effects of ambrisentan in treatment of pulmonary arterial hypertension: a pilot study with 15 patients].

OBJECTIVE: To investigate the preliminary efficacy and safety of ambrisentan, a selective endothelin receptor antagonist, in patients with pulmonary arterial hypertension (PAH). METHODS: A total of 15 patients with PAH, including 10 patients with idiopathic PAH and 5 patients with associated connective-tissue disease, received 2.5 mg or 5 mg of ambrisentan once daily for 12 weeks. Before and after 12 weeks treatment, 6-minute walk test (6-MWD), WHO functional classification (WHO FC) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured. RESULTS: After 12 weeks treatment, the 6-MWD was significantly increased [(376.5 ± 108.2) m vs.(460.3 ± 95.7) m, P = 0.021] and the systolic pulmonary artery was significantly decreased [(85.0 ± 33.3) mm Hg (1 mm Hg = 0.133 kPa)vs. (70.5 ± 30.5) mm Hg,P = 0.015] and NT-proBNP was significantly reduced [892.0 (99.0-2245.0) ng/L vs. 205.0 (56.0-534.0) ng/L, P = 0.026] than before treatment. WHO FC was improved in 4 patients after 12 weeks treatment. No patient was withdrawn from this study for safety reasons. CONCLUSIONS: Ambrisentan treatment can effectively improve the exercise capacity, and reduce systolic pulmonary artery pressure and NT-proBNP in PAH patients. Ambrisentan use is safe and could be well tolerated in Chinese PAH patients.

Single-Cell Transcriptome Analysis of Peripheral Neutrophils From Patients With Idiopathic Pulmonary Arterial Hypertension.

BACKGROUND: Idiopathic pulmonary hypertension (IPAH) is a rare and devastating disease often accompanied by persistent inflammation and immune responses. We aim to provide a reference atlas of neutrophils to facilitate a better understanding of cellular phenotypes and discovery of candidate genes. METHODS: Peripheral neutrophils from naive patients with IPAH and matched controls were profiled. Whole-exon sequencing was performed to exclude known genetic mutations before establishing single-cell RNA sequencing. Marker genes were validated by flow cytometry and histology in a separate validation cohort. RESULTS: Seurat clustering analysis revealed that the landscape of neutrophils encompassed 5 clusters, including 1 progenitor, 1 transition, and 3 functional clusters. The intercorrelated genes in patients with IPAH were mainly enriched in antigen processing presentation and natural killer cell mediated cytotoxicity. We identified and validated differentially upregulated genes, including MMP9 (matrix metallopeptidase 9), ISG15 (ISG15 ubiquitin-like modifier), and CXCL8 (C-X-C motif ligand 8). The positive proportions and fluorescence quantification of these genes were significantly increased in CD16+ neutrophils in patients with IPAH. The higher proportion of positive MMP9 neutrophils increased mortality risk after adjustment for age and sex. Patients with higher proportions of positive MMP9 neutrophils had worse survival, while the fraction of ISG15- or CXCL8-positive expression neutrophils failed to predict outcome. CONCLUSIONS: Our study yields a comprehensive dataset of the landscape of neutrophils in patients with IPAH. The predictive values of a neutrophil cluster characterized by higher MMP9 expression indicate a functional role for neutrophil-specific matrix metalloproteinases in the pathogenesis of pulmonary arterial hypertension.

Identification of the shared gene signatures between pulmonary fibrosis and pulmonary hypertension using bioinformatics analysis.

Pulmonary fibrosis (PF) and pulmonary hypertension (PH) have common pathophysiological features, such as the significant remodeling of pulmonary parenchyma and vascular wall. There is no effective specific drug in clinical treatment for these two diseases, resulting in a worse prognosis and higher mortality. This study aimed to screen the common key genes and immune characteristics of PF and PH by means of bioinformatics to find new common therapeutic targets. Expression profiles are downloaded from the Gene Expression Database. Weighted gene co-expression network analysis is used to identify the co-expression modules related to PF and PH. We used the ClueGO software to enrich and analyze the common genes in PF and PH and obtained the protein-protein interaction (PPI) network. Then, the differential genes were screened out in another cohort of PF and PH, and the shared genes were crossed. Finally, RT-PCR verification and immune infiltration analysis were performed on the intersection genes. In the result, the positive correlation module with the highest correlation between PF and PH was determined, and it was found that lymphocyte activation is a common feature of the pathophysiology of PF and PH. Eight common characteristic genes (ACTR2, COL5A2, COL6A3, CYSLTR1, IGF1, RSPO3, SCARNA17 and SEL1L) were gained. Immune infiltration showed that compared with the control group, resting CD4 memory T cells were upregulated in PF and PH. Combining the results of crossing characteristic genes in ImmPort database and RT-PCR, the important gene IGF1 was obtained. Knocking down IGF1 could significantly reduce the proliferation and apoptosis resistance in pulmonary microvascular endothelial cells, pulmonary smooth muscle cells, and fibroblasts induced by hypoxia, platelet-derived growth factor-BB (PDGF-BB), and transforming growth factor-ß1 (TGF-ß1), respectively. Our work identified the common biomarkers of PF and PH and provided a new candidate gene for the potential therapeutic targets of PF and PH in the future.

[Clinical characteristics of 161 Chinese patients with idiopathic pulmonary arterial hypertension].

OBJECTIVE: To investigate the clinical characteristics of patients with idiopathic pulmonary arterial hypertension (IPAH) in China. METHODS: A total of 161 patients diagnosed as IPAH in Shanghai Pulmonary Hospital from June 2008 to June 2010 were retrospective analyzed. RESULTS: The mean diagnostic age was (33 ± 15) years old and 70.2% patients were female. The median duration from symptoms onset to diagnostic right heart catheterization was 12 months. Incidence of NYHA class III to IV was 56.5% at diagnosis and the mean six minutes walk distance was limited to (398 ± 108) meters. Incidence of mild obstructive, restrictive and diffusing impairment in pulmonary function test was 7.8%, 42.2% and 82.2% patients with IPAH, respectively. Right heart catheterization demonstrated severe elevated mean pulmonary arterial pressure [(63 ± 17) mm Hg (1 mm Hg = 0.133 kPa)] and pulmonary vascular resistance index [(25 ± 12) Wood U/m(2)] in this patient cohort. The response rate of acute pulmonary vasoreactivity testing was 8.7% in this cohort. Compared with non-responders, responders to acute pulmonary vasoreactivity testing were younger and with less severe pulmonary hypertension. Among non-responders, 89% patients were treated by one specific anti-pulmonary arterial hypertension drug and 27% patients received combined anti-pulmonary arterial hypertension medications. CONCLUSIONS: Young female was predominantly involved in patients with IPAH in China. The diagnosis of IPAH is often made at advanced disease stage and majority patients with IPAH received specific anti-pulmonary arterial hypertension therapies in this patient cohort.

Clinical phenotypes, hemodynamic characteristics and prognosis of Chinese patients with systemic sclerosis-associated precapillary pulmonary hypertension: a retrospective study.

INTRODUCTION: Systemic sclerosis (SSc) is associated with interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). This study aimed to explore the prevalence, clinical features, hemodynamic characteristics and prognosis of different severity of ILD in a cohort of patients with SSc-associated precapillary pulmonary hypertension (SSc-PH) and investigate the differences between SSc-PAH and idiopathic pulmonary arterial hypertension (IPAH) patients. METHOD: SSc-PH patients and IPAH patients, admitted to Shanghai Pulmonary Hospital (August 1, 2008-January 31, 2020) and diagnosed by right-sided heart catheterization (RHC) or echocardiography, were retrospectively included. SSc-PH patients had a baseline chest high-resolution computed tomography (HRCT), and PH classification was based on the extent of ILD. Clinical, pulmonary function, hemodynamic characteristics and survival data were extracted. RESULTS: The study included 45 SSc-PH patients (60% had coexisting ILD and 77.8% were SSc-Group 1 PH/SSc-PAH [without ILD or with mild ILD], 22.2% were SSc-Group 3 PH/SSc-PH with severe ILD) and 52 IPAH patients. SSc-PH with ILD had lower arterial oxygen partial pressure (PaO2) than those without ILD. Hemodynamic characteristics and survival rates were comparable between SSc-PAH with mild ILD and those without ILD. SSc-Group 3 PH had lower pulmonary vascular resistance (PVR) and more severe restrictive ventilatory dysfunction than SSc-Group 1 PH, but the survival rate was equally poor. SSc-PAH had a poorer prognosis than IPAH patients despite the better hemodynamic characteristics. CONCLUSIONS: ILD was common in SSc-PH patients. Careful phenotyping of PH in SSc-PH patients is very important as it is imperative to recognize its impact on clinical course, treatment and survival. KEY POINTS: • ILD was common in Chinese SSc-PH patients. • SSc-PH patients with ILD had lower PaO2 than those without ILD. • Hemodynamic characteristics and survival rates were similar in SSc-PAH patients with mild ILD and those without ILD. • Patients in SSc-Group 3 PH had lower pulmonary vascular resistance (PVR) and more severe restrictive ventilatory dysfunction than those in SSc-Group 1 PH, but the survival rate was equally poor. SSc-PAH patients had a poorer prognosis than IPAH patients despite their better hemodynamic characteristics.

Echocardiography Nomogram for Predicting Survival among Chronic Lung Disease Patients with Severe Pulmonary Hypertension.

Severe pulmonary hypertension in chronic lung diseases (severe CLD-PH) differs significantly from other types of PH in physiology and prognosis. We aimed to assess whether echocardiography helps predict long-term survival in patients with severe CLD-PH. This single-centre, observational cohort study enrolled 100 patients with severe CLD-PH (mean pulmonary arterial pressure ≥35 mm Hg or ≥25 mm Hg with cardiac index <2.0 L/min/m2 or pulmonary vascular resistance ≥6 Wood units) between 2009 and 2014. The population was randomly divided into a derivation and validation cohort in a 2:1 ratio. To construct a nomogram, a multivariable logistic regression model was applied, and scores were assigned based on the hazard ratio of independent echocardiographic predictors. Multivariate Cox hazards analysis identified the strongest predictors of mortality as pulmonary arterial systolic pressure (PASP), tricuspid annular plane systolic excursion, and right ventricular end-diastolic transverse dimension. The three independent predictors were entered into the nomogram. Compared with PASP alone, the nomogram resulted in an integrated discrimination improvement of 15.5% (95% confidence interval, 5.52−25.5%, p = 0.002) with a net improvement in model discrimination (C-statistic from 0.591 to 0.746). Using echocardiographic parameters, we established and validated a novel nomogram to predict all-cause death for patients with severe CLD-PH.

Time-Velocity Integral of Left Ventricular Outflow Tract Predicts Worse Long-Term Survival in Pulmonary Arterial Hypertension.

Background: The time-velocity integral of the left ventricular outflow tract (TVILVOT) has been demonstrated to correlate with heart failure hospitalization and mortality, but the association of TVILVOT with the severity and prognosis of pulmonary arterial hypertension (PAH) has not been evaluated. Objectives: The aim of this study was to investigate the predictive value of baseline TVILVOT in PAH. Methods: A total of 225 consecutive patients with a diagnosis of incident PAH were prospectively studied and echocardiology-derived TVILVOT was measured at enrollment followed by right heart catheterization examination within 48 hours. Cox proportional hazards analysis was performed to assess the association between baseline variables and mortality. Results: During a median follow-up period of 33.8 months, 44 patients died of cardiovascular events. Baseline TVILVOT was significantly lower in the nonsurvivors compared with the survivors (P < 0.001). Baseline TVILVOT was positively correlated with stroke volume obtained by right heart catheterization (r = 0.709; P < 0.001), and inversely correlated with N-terminal pro-B-type natriuretic peptide (r = -0.533; P < 0.001), pulmonary vascular resistance (r = -0.423; P < 0.001). Multivariate analysis showed that baseline TVILVOT (hazard ratio: 0.856; 95% CI: 0.780-0.941; P = 0.001) was an independent predictor of cardiovascular mortality in PAH. Patients with a baseline TVILVOT <17.1 cm (median value) had a significantly worse survival than those with a baseline TVILVOT ≥17.1 cm (P < 0.001). Conclusions: The findings of this study suggest that noninvasive TVILVOT provides a practical method to assess the severity and predict long-term outcome of PAH.

Sex-specific differences in sleep-disordered breathing and nocturnal hypoxemia in chronic thromboembolic pulmonary hypertension and chronic thromboembolic pulmonary disease.

Objective: Although chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic pulmonary disease (CTEPD) are known to be accompanied by symptoms associated with sleep-disordered breathing (SDB) and nocturnal hypoxemia, the sex-specific differences of SDB and nocturnal hypoxemia in patients with CTEPH and CTEPD remain unknown. Methods: Between July 2020 and August 2022, data were retrieved from 57 males and 63 female patients with CTEPH and CTEPD who underwent sleep study at Shanghai Pulmonary Hospital. Nocturnal mean SpO2 (mean SpO2) < 90% was defined as nocturnal hypoxemia. Logistic and linear regression analysis was performed to assess the predictive value of sleep study indices to hemodynamic parameters. Receiver operating characteristic (ROC) curve was applied to analyze the specific parameters to predict the risk of CTEPH. Results: SDB was similarly present in males and females, and both sexes predominantly had obstructive sleep apnea (OSA); more women were diagnosed with nocturnal hypoxemia (32 vs. 7%, p = 0.002). SaO2 was negatively associated with mean pulmonary arterial pressure (mPAP) in men (p < 0.001), whereas the ratio of nocturnal SpO2 < 90% of the total monitoring time (T90%) was positively correlated with mPAP. Mean SpO2 was an independent predictor for pulmonary vascular resistance and cardiac output in women (p = 0.001, p < 0.001, p = 0.001, respectively). T90%, SaO2, and minimal SpO2 were combined to develop a new composite parameter: hypoxemia scoring index (HSI). ROC curve analysis indicated that HSI levels of 0.55 could discriminate CTEPH from CTEPD with a sensitivity of 92.3% and specificity of 87.5% in female patients (an area under the curve, 0.937; 95% CI: 0.879-0.995, p < 0.001). Conclusion: Sex-specific nocturnal hypoxemia was present in patients with CTEPH or CTEPD. In female patients, the HSI showed high capacity for predicting the risk of CTEPH. Clinical trials registration: Registry: chictr.org.cn; Identifier: ChiCTR-DDD-16009406.

A Study of the Efficacy and Safety of Aerobic Exercise Training in Pulmonary Arterial Hypertension (the Saturday Study): Protocol for a Prospective, Randomized, and Controlled Trial.

Background: Patients with pulmonary arterial hypertension (PAH) have reduced exercise capacity and poor quality of life. Exercise-based rehabilitation in PAH results in clinically relevant improvements in exercise capacity and hemodynamics. To clarify the mechanism, we will evaluate the effect of aerobic exercise training rehabilitation on right ventricular (RV) remodeling and function as determined measured by cardiac magnetic resonance imaging (CMR). Methods: We will conduct a 26-week multicenter randomized controlled trial. Patients on stable and unchanged PAH-targeted medication are randomly assigned (1:1) to the control and training groups. The primary endpoint is the RV stroke volume (RVSV) change from baseline to Week 26, determined by CMR. Comprehensive RV function is also performed using CMR. Other characteristics of the RV and left ventricle, World Health Organization functional class, 6-min walk distance, and N-terminal pro-B-type natriuretic peptide are included in secondary endpoints. We also investigate the proteomic, metabolomic, and transcriptomic changes after exercise training as exploratory endpoints. Ethics and Dissemination: The study and protocol were approved by the Ethics Committee of Shanghai Pulmonary Hospital (Approved No. of ethics committee: L20-17). The results will be disseminated at medical conferences and in journal publications. All participants will sign written informed consent. Trial Registration Number: ChiCTR2000031650.

Differences in disease severity and prognosis of exercise-induced right-to-left shunt between idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients.

Objective: Whether exercise-induced venous-to-systemic shunt (EIS) during cardiopulmonary exercise testing (CPET) has different manifestations or characteristics in idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients remains unknown. We explored the differences in hemodynamics, echocardiography, and prognosis between IPAH and CTEPH patients with and without EIS. Methods: We conducted a retrospective cross-sectional cohort study and included 161 PH patients at Shanghai Pulmonary Hospital. Demographic, echocardiography, pulmonary hemodynamic, and CPET variables were compared between patients with and without EIS stratified by IPAH and CTEPH. EIS was determined by CPET. Binary logistic regression analyses were performed to explore independent influencing factors of EIS. Cox survival analysis was used to quantify the impact of EIS on the prognosis of patients. Results: Exercise-induced venous-to-systemic shunt was found in approximately 17.4% of 86 IPAH patients and 20% of 75 CTEPH patients. All-cause mortality occurred in 43 (26.7%) patients during a median follow-up of 6.5 years. Compared with those without EIS, patients with EIS had higher peak end-tidal O2 and lower VO2/VE and tricuspid annular plane systolic excursion (TAPSE). Among the IPAH patients, EIS was associated with lower cardiac output, cardiac index, mixed venous oxygen saturation, VO2/VE, and TAPSE and higher VE/VCO2 and right ventricular end-diastolic transverse diameter. Logistic regression analysis indicated that VO2/VE was an independent factor influencing whether IPAH patients developed EIS during CPET. Cox logistic regression indicated that female IPAH patients or IPAH patients with higher VO2/VE and EIS had a better prognosis. Female IPAH patients had better 10-year survival. In IPAH patients without EIS, patients with higher VO2/VE had better 10-year survival. However, compared with CTEPH patients without EIS, those with EIS had similar echocardiographic, hemodynamic, CPET parameter results and 10-year survival. Conclusion: Exercise-induced venous-to-systemic shunt exhibits different profiles among IPAH and CTEPH patients. Among IPAH patients, those with EIS had worse peak end-tidal O2, VO2/VE, and TAPSE than those without EIS. VO2/VE was an independent factor of EIS among IPAH patients. IPAH patients with EIS, female sex or higher VO2/VE had better survival. However, the association between EIS and PAH severity or prognosis in CTEPH patients needs to be further explored.

Long-term outcomes in health-related quality of life influence chronic disease management in patients with pulmonary hypertension.

Background: Significantly improved survival in patients with pulmonary hypertension (PH) has raised interest in maintaining a good quality of long-term survivorship. In this study, health-related quality of life (HRQOL) measurement was used to assess the long-term changes of physical and mental outcomes. Methods: A total of 559 consecutive inpatients with PH completed generic HRQOL (Short Form-36) who were diagnosed with PH by right heart catheterization. Assessments were carried out at short-term (1 year), midterm (3 years), and long-term (5 years) follow-ups. Results: Patients with PH suffered more severe impairments in both physical and emotional domains than the U.S. population normative values. Patients with PH due to chronic lung disease had the worst physical component summary (PCS) score, but there was no difference in mental component summary (MCS) score among different PH types. A reduced PCS score was correlated with WHO FC severity and pulmonary vascular resistance (PVR). The Z score showed that the changing trend of mental conditions continuously declined from baseline to midterm and long-term follow-ups, but the PCS score seemed to be stable or improved. Cox regression analysis indicated increased baseline PVR and WHO FC III and IV, and decreased physical subscale of role physical, mental subscale of social functioning, and the MCS score have increased risk of mortality in the long-term follow-up. Conclusion: Patients with PH have poor HRQOL. The long-term change of physical status seemed to be stable, but the mental state was continuously worse. These suggested identifying and intervening mental health progresses is a noteworthy issue in PH chronic management.

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

Background: There is little evidence of the effectiveness of switching from the endothelin receptor antagonists (ERAs) bosentan and ambrisentan to a novel ERA, macitentan, in patients with pulmonary arterial hypertension (PAH). Therefore, a systematic review and meta-analysis was performed to evaluate the efficacy and safety of patients with PAH switching from other ERAs to macitentan. Methods: We retrieved the relevant literature published before January 2022 for the meta-analysis from the PubMed, EMBASE, and Cochrane Library databases. Efficacy included changes in the 6-min walk distance (6MWD), World Health Organization functional class (WHO-FC), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, hemodynamics, echocardiography and survival. Results: Nine studies, consisting of 408 PAH patients, that met the inclusion criteria were included. The switch from bosentan or ambrisentan to macitentan effectively increased the 6MWD by 20.71 m (95% CI: 10.35-31.07, P < 0.00001, I 2 = 0%). Six months after conversion, the tricuspid annular plane systolic excursion was found to improve from 19.0 ± 4.0 to 21.0 ± 5.0 mm in adults and from 16.00 ± 5.0 to 18.25 ± 4.8 mm in children. Ordinal logistic regression showed that the WHO-FC significantly improved by 0.412 (95% CI: 0.187-0.908, P = 0.028). The switch did not show significant improvement in NT-proBNP levels. In addition, the switch was well tolerated. Conclusion: The switch from bosentan or ambrisentan to macitentan significantly increased the 6MWD in PAH patients, improved the WHO-FC, and exerted safety benefits. The effects of the switch on NT-proBNP levels, hemodynamics, and echocardiography still need to be further confirmed. Systematic review registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021292554].