Predictive factors of hospitalization for acute exacerbation in a series of 64 patients with chronic obstructive pulmonary disease

Survival and response to pulmonary vasodilator therapies in patients with chronic obstructive pulmonary disease and pulmonary vascular phenotype

BACKGROUND

The aim of the study was to describe and investigate the effect of pulmonary arterial hypertension (PAH) therapies in a cohort of patients with severe precapillary pulmonary hypertension (PH) associated with chronic obstructive pulmonary disease (COPD; PH-COPD), and to assess factors predictive of treatment response and mortality.

MATERIAL AND METHODS

We retrospectively included patients with severe incident PH-COPD who received PAH therapy and underwent RHC at diagnosis and on treatment.

RESULTS

From 2015 to 2022, 35 severe PH-COPD patients, with clinical features of pulmonary vascular phenotype, were included. Seventeen (48.5%) patients were treated with combined PAH therapy. PAH therapy led to a significant improvement in hemodynamics (PVR -3.5 Wood Units (-39.3%); p < 0.0001), and in the simplified four-strata risk-assessment score, which improved by at least one category in 21 (60%) patients. This effect was more pronounced in patients on dual therapy. Kaplan-Meier estimated survival rates at 1, 3 and 5 years were 94%, 65% and 42% respectively. Univariate analysis showed a significant reduction in survival in patients with a higher simplified risk score at follow-up (Hazard ratio (HR) 2.88 [1.16-7.15]; p = 0.02). Hypoxemia <50 mmHg was correlated to mortality in multivariate analysis (HR 4.33 [1.08-17.42]; p = 0.04).

CONCLUSIONS

Our study confirms the poor prognosis of patients with COPD and a pulmonary vascular phenotype and the potential interest of combined PAH therapy in this population, with good tolerability and greater clinical and hemodynamic improvement than monotherapy. Using the simplified risk score during follow-up could be of interest in this population.

Efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension patients with pulmonary comorbidity

Background

Balloon pulmonary angioplasty (BPA) is an established treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but its efficacy in CTEPH patients with a pulmonary comorbidity has not been well-studied. Here, we compared post-BPA outcomes between CTEPH patients with and without chronic pulmonary disease at baseline and analyzed predictors of BPA success.

Methods

From August 2017 to October 2022, 62 patients with inoperable CTEPH who underwent BPA were consecutively enrolled and grouped based on the presence of a pulmonary comorbidity at baseline. All patients underwent transthoracic echocardiography, pulmonary function tests, and right heart catheterization. Pre- and post-BPA data were evaluated to identify factors that influence the success of BPA.

Results

Among the 62 CTEPH patients, BPA was considered successful in 50 patients and unsuccessful in 12 patients. Responders to BPA had better exercise capacity and right heart function at baseline, but no differences in hemodynamic or respiratory function were detected between the groups. In CTEPH patients with chronic pulmonary disease (n = 14), BPA significantly improved mean pulmonary arterial pressure, pulmonary vascular resistance and right heart function parameters. Only CTEPH patients without chronic pulmonary disease (n = 48) exhibited significant improvement in 6-minute walk distance and respiratory function. Multivariate logistic regression analysis showed that pulmonary comorbidity at baseline was independently associated with the efficacy of BPA.

Conclusions

BPA provided significantly improvements in hemodynamics and right heart function in CTEPH patients, independent of pulmonary comorbidity at baseline. However, pulmonary comorbidity can negatively impact post-BPA outcomes.

Clinical course of COPD patients with exercise-induced elevation of pulmonary artery pressure or less severe pulmonary hypertension presenting with respiratory symptoms and the impact of bosentan intervention-prospective, single-center, randomized, parallel-group study

BACKGROUND

The data on bosentan were lacking for the treatment of exercise-induced elevation of pulmonary artery pressure (eePAP) or less severe PH in COPD. This study was conducted to investigate long-term efficacy and safety of bosentan for the treatment of eePAP or less severe PH in COPD.

METHODS

COPD patients diagnosed at this hospital as having COPD (WHO functional class II, III or IV) with eePAP or less severe PH whose respiratory symptoms were stable but remained and gradually progressed even after COPD therapy were randomly assigned in a 1:1 ratio to receive either bosentan or no PH treatment for two years and assessed at baseline and every 6 months for respiratory failure, activities of daily living (ADL), lung and heart functions by right heart catheterization (RHC), and other parameters.

RESULTS

A total of 29 patients who underwent RHC for detail examination were enrolled in the current study between August 2010 and October 2018.No death occurred in drug-treated group (n = 14) for 2 years; 5 patients died in untreated group (n = 15). Significant differences were noted between the 2 group in hospital-free survival (686.00 ± 55.87 days vs. 499.94 ± 53.27 days; hazard ratio [HR], 0.18; P = 0.026) and overall survival (727 days vs. 516.36 ± 55.38 days; HR, 0.095; P = 0.030) in all causes of death analysis, but not in overall survival in analysis of respiratory-related death. Bosentan was not associated with increased adverse events including requiring O2 inhalation.

CONCLUSIONS

This study suggested that the prognosis for COPD patients with eePAP or less severe PH presenting with respiratory symptoms was very poor and that bosentan tended to improve their prognosis and suppress ADL deterioration without worsening respiratory failure.

TRIAL REGISTRATION

This study was registered with UMIN-CTR Clinical Trial as UMIN000004749 . First trial registration at 18/12/2010.

Impacts of regular physical activity on hospitalisation in chronic obstructive pulmonary disease: a nationwide population-based study

INTRODUCTION

Studies that comprehensively evaluate the association between physical activity (PA) levels, particularly by quantifying PA intensity, and healthcare use requiring emergency department (ED) visit or hospitalisation in patients with chronic obstructive pulmonary disease (COPD) are limited in Korea.

METHODS

The risk of all-cause and respiratory ED visit or hospitalisation according to the presence or absence of COPD and the level of PA was evaluated in a retrospective nationwide cohort comprising 3308 subjects with COPD (COPD cohort) and 293 358 subjects without COPD (non-COPD cohort) from 2009 to 2017.

RESULTS

The COPD group exhibited a higher relative risk of all-cause and respiratory ED visit or hospitalisation across all levels of PA compared with the highly active control group (≥1500 metabolic equivalents (METs)-min/week). Specifically, the highest risk was observed in the sedentary group (adjusted HR (aHR) (95% CI) = 1.70 (1.59 to 1.81) for all-cause ED visit or hospitalisation, 5.45 (4.86 to 6.12) for respiratory ED visit or hospitalisation). A 500 MET-min/week increase in PA was associated with reductions in all-cause and respiratory ED visit or hospitalisation in the COPD cohort (aHR (95% CI) = 0.92 (0.88 to 0.96) for all-cause, 0.87 (0.82 to 0.93) for respiratory cause).

CONCLUSIONS

Compared with the presumed healthiest cohort, the control group with PA>1500 METs-min/week, the COPD group with reduced PA has a higher risk of ED visit or hospitalisation.

Echocardiography and pulmonary hypertension in patients with chronic obstructive pulmonary disease undergoing lung transplantation evaluation

BACKGROUND

The use of echocardiography in pulmonary hypertension (PH) in advanced chronic obstructive pulmonary disease (COPD) is understudied. We aimed to compare the performance of echocardiography with right heart catheterization (RHC) in the diagnosis of PH in COPD patients undergoing lung transplant evaluation.

METHODS

We included 111 patients with severe COPD who underwent RHC in a single center as part of lung transplantation evaluation. COPD-PH and severe COPD-PH were defined based on RHC per the 6th world symposium on pulmonary hypertension. Echocardiographic probability of PH was described according to the European Society of Cardiology guidelines. Summary and univariate analyses were performed.

RESULTS

The mean age (±SD) was 62 (8) and 47% (n=52) were men. A total of 82 patients (74 %) had COPD-PH. The sensitivity, specificity, positive predictive, and negative predictive values of echocardiography in diagnosing COPD-PH were 43 %, 83 %, 88 %, and 34 % respectively and for severe COPD-PH were 67 %, 75 %, 50 %, and 86 % respectively. Echocardiography was consistent with RHC in ruling in/out PH in 53% (n=59) of patients. After controlling for age, sex. BMI, pack year, echocardiography-RHC time difference, GOLD class, FVC, and CT finding of emphysema, higher TLC decreased consistency (parameter estimate=-0.031; odds ratio: 0.97, 95%CI 0.94-0.99; p=0.037) and higher DLCO increased consistency (parameter estimate=0.070; odds ratio: 1.07, 95%CI 0.94-0.99; p=0.026).

CONCLUSIONS

Echocardiography has high specificity but low sensitivity for the diagnosis of PH in advanced COPD. Its performance improves when ruling out severe COPD-PH. This performance correlates inversely with lung hyperinflation.

[Pulmonary hypertension associated with lung disease]

Lung diseases and hypoventilation syndromes are often associated with pulmonary hypertension (PH). In most cases, PH is not severe. This is defined hemodynamically by a mean pulmonary arterial pressure (PAPm) > 20 mmHg, a pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg and a pulmonary vascular resistance of ≤ 5 Wood units (WU). Both the non-severe (PVR ≤ 5 WU) and much more the severe PH (PVR > 5 WU) have an unfavorable prognosis.If PH is suspected, it is recommended to primarily check whether risk factors for pulmonary arterial hypertension (PAH, group 1 PH) or chronic thromboembolic pulmonary hypertension (CTEPH, group 4 PH) are present. If risk factors are present or there is a suspicion of severe PH in lung patients, it is recommended that the patient should be presented to a PH outpatient clinic promptly.For patients with severe PH associated with lung diseases, personalized, individual therapy is recommended - if possible within the framework of therapy studies. Currently, a therapy attempt with PH specific drugs should only be considered in COPD patients if the associated PH is severe and a "pulmonary vascular" phenotype (severe precapillary PH, but typically only mild to moderate airway obstruction, no or mild hypercapnia and DLCO < 45 % of predicted value) is present. In patients with severe PH associated with interstitial lung disease phosphodiesterase-5-inhibitors may be considered in individual cases. Inhaled treprostinil may be considered also in non-severe PH in this patient population.

Lung Transplantation for Pulmonary Arterial Hypertension

TOPIC IMPORTANCE

Even though patients with pulmonary arterial hypertension have multiple therapeutic options, the disease can be refractory despite appropriate management. In patients with end-stage pulmonary arterial hypertension, lung transplantation has the potential both to extend survival and improve health-related quality of life. Pulmonary arterial hypertension is the only major diagnostic indication for transplantation that is not a parenchymal pulmonary process, and thus the care of these patients is unique.

REVIEW FINDINGS

This review focuses on the complexities of lung transplantation for patients with pulmonary arterial hypertension, presents the updated referral and listing criteria, and discusses the inequities in the organ allocation process that impact this disease group and the strategies to optimize outcomes for patients with pulmonary arterial hypertension who require lung transplantation.

SUMMARY

Lung transplantation is an effective and lifesaving therapy for patients with end-stage lung disease. Sadly, patients with pulmonary arterial hypertension face many challenges as it relates to transplantation including higher perioperative risks, inequities in the allocation system, and less favorable long-term outcomes. This review covers the complexities of transplantation in patients with pulmonary vascular disease.

Quantitative CT measures of pulmonary vascular volume distribution in pulmonary hypertension associated with COPD: Association with clinical characteristics and outcomes

To determine whether quantitative computed tomography (qCT)-derived metrics of pulmonary vascular volume distribution could distinguish chronic obstructive pulmonary disease (COPD) subjects with associated pulmonary hypertension (PH) from those without and to characterize associations of these measurements with clinical and physiological characteristics and outcomes. We collected retrospective CT, pulmonary hemodynamic, clinical, and outcomes data from subjects with COPD and right-heart catheterization-confirmed PH (PH-COPD) and control subjects with COPD but without PH. We measured the volumes of pulmonary vessels < 5 and >10 mm2 in cross-sectional area as a percentage of total pulmonary vascular volume (qCT-derived volume of pulmonary vessels < 5 mm2 in cross-sectional area as a volume fraction of total pulmonary blood volume [BV5%] and qCT-derived volume of pulmonary vessels > 10 mm2 in cross-sectional area [BV10] as a volume fraction of total pulmonary blood volume [BV10%], respectively) using Functional Respiratory Imaging (FRI), an automated qCT platform, and compared them between PH and control arms and between subjects with mild-moderate PH and those with severe disease. Correlations of hemodynamics with pulmonary function and associations with survival were tested. Forty-five PH-COPD and 42 control subjects were studied. BV5% was lower in PH subjects (32.2% vs. 37.7%, p = 0.003), and BV10% was higher (50.2% vs. 43.5, p = 0.001). Subjects with severe PH did not differ from those with mild-moderate PH in qCT. Pulmonary vascular volumes were not associated with pulmonary function. BV10 was associated with mean pulmonary artery pressure (r = 0.3, p = 0.05). Associations with survival were observed for BV5% (hazard ratio 0.63, p = 0.02) and BV10% (hazard ratio 1.43, p = 0.03) in the PH-COPD arm, but not for controls. qCT-derived measures of pulmonary vascular volume may have diagnostic and prognostic significance in PH-COPD and should be investigated further as screening and risk stratification tools.

Impact of targeted pulmonary arterial hypertension therapies in severe pulmonary hypertension in chronic lung diseases

Research questions

Patients with severe pulmonary hypertension associated with chronic lung disease have a poor prognosis. Targeted pulmonary arterial hypertension therapies might improve exercise capacity and outcome, but there are no guidelines on treatments which are not recommended because of an unproven benefit, with discordant results from few studies in this context. The aim of our study was to evaluate targeted pulmonary arterial hypertension therapies for severe group 3 pulmonary hypertension patients.

Study design and methods

We conducted an observational retrospective monocentre study on patients with severe group 3 pulmonary hypertension diagnosed on right heart catheterisation treated with targeted therapies. Primary outcome was an improvement of the distance on 6-min walk test of ≥30 m. Secondary end-points included changes in haemodynamics (pulmonary vascular resistance (PVR) and mean pulmonary arterial pressure (mPAP)) and identification of potential predictive factors of therapeutic response.

Results

139 patients were enrolled. Most patients had monotherapy with phosphodiesterase 5 inhibitors (n=128; 92%). Mean change in 6-min walk distance was +1.5 m after treatment (p=0.59). Forced expiratory volume in 1 s and forced vital capacity were not predictive factors for response. We found a significant improvement of PVR and mPAP of -1.0 Wood Units (p<0.001) and -4 mmHg (p<0.001), respectively, under treatment. 18% of patients had to withdraw treatment for intolerance. Treatment duration <3 months was associated with poor survival (hazard ratio 2.75, p=0.0005).

Conclusion

Oral targeted pulmonary arterial hypertension therapies do not improve exercise capacity in patients with severe pulmonary hypertension associated with chronic lung disease, but could improve haemodynamic parameters.

FVC/DLCO identifies pulmonary hypertension and predicts 5-year all-cause mortality in patients with COPD

BACKGROUND

Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD). However, it is unknown whether the ratio of forced vital capacity (FVC) to diffusing lung capacity for carbon monoxide (D_LCO) can identify PH in the patients with COPD and predict its prognosis.

METHODS

The study population I included 937 COPD patients who were admitted to inpatient treatments from 2010 to 2017, and finally 750 patients were available to follow-up the 5-year all-cause mortality (study population II). Clinical characteristics of the study population were recorded.

RESULTS

COPD patients with PH had a higher FVC/D_LCO value compared with the patients without PH. The threshold for FVC/D_LCO to identify PH in COPD patients was 0.44 l/mmol/min/kPa. Multivariate logistic regression analysis showed that FVC/D_LCO was a significant predictor for PH in the patients with COPD. The study population II showed that the 5-year all-cause mortality of COPD patients was significantly higher in combined with PH group than without PH group. Compared with the survivor group, FVC/D_LCO value was significantly increased in non-survivor group. The threshold for FVC/D_LCO to predict 5-year all-cause mortality was 0.41 l/mmol/min/kPa. Kaplan-Meier survival curves showed that 5-year cumulative survival rate for COPD patients were significantly decreased when the value of FVC/D_LCO was ≥ 0.41 l/mmol/min/kPa. Multivariate cox regression analysis showed that FVC/D_LCO was an independent prognostic factor for 5-year all-cause mortality in COPD patients.

CONCLUSION

FVC/D_LCO could identify PH in the patients with COPD and was an independent predictor for 5-year all-cause mortality of COPD.

Effect of Long-Term Oxygen Therapy on Reducing Rehospitalization of Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

The aim of this work is to evaluate whether the addition of home oxygen therapy (HOT) would reduce readmission in chronic obstructive pulmonary disease (COPD) patients.

METHODS

PubMed, ScopeMed, Cochrane, Scopus, and Google Scholar databases were searched. The search strategy used the following keywords "chronic obstructive pulmonary disease", the intervention "long-term oxygen therapy", and the outcome "readmission" combined with the AND operator. The Newcastle-Ottawa Scale and Jadad Scale were used for assessing the quality of cohort studies and clinical trials, respectively. A random-effects model was employed in this study after calculating the standard errors by 95% confidence intervals. The I2 statistic and Cochran's Q-test were used to measure heterogeneity. To address heterogeneity, subgroup analyses were carried out according to the length of LTOT, which was classified as "over 8 months" and "under 8 months".

RESULTS

Seven studies were included in the analysis. In the pooled analysis, the RR [CI95%, p value], heterogeneity criteria for readmission reduced by 1.542 [1.284-1.851, < 0.001], I² = 60%, and 1.693 [1.645-1.744, < 0.001], I² = 60% for patients with a length of LTOT treatment under and above 8 months, respectively. A sensitivity analysis was conducted by systematically omitting each study, and it showed no influential studies. Egger's test indicated no publication bias (p = 0.64).

CONCLUSIONS

Based on our results in this systematic review, long-tern oxygen therapy (LTOT) at home was associated with a significantly lower risk ratio of hospital readmission. However, the sample sizes in the studies necessitate larger RCTs to evaluate the effect of LTOT on readmission in COPD patients.

Relationship between abnormal P-wave axis, chronic obstructive pulmonary disease and mortality in the general population

BACKGROUND

It is unclear whether the presence of a vertical P-wave axis on electrocardiogram modifies the association of COPD with mortality.

OBJECTIVE

To examine the association and interaction of abnormal P-wave axis and COPD with mortality.

STUDY DESIGN AND METHODS

The analysis included 7359 with ECG data from the Third National Health and Nutrition Examination Survey (NHANES-III) who were free of cardiovascular disease (CVD) at enrollment. Abnormal P-wave axis (aPWA) was defined as values above 75°. COPD was self-reported as either a diagnosis of emphysema or chronic bronchitis. National Death Index was used to identify the date of death and cause of death. Using multivariable Cox proportional hazard analysis, we examined the association of COPD with all-cause mortality by aPWA status.

RESULTS

Over a median follow-up of 14 years, 2435 deaths occurred. Participants with concomitant presence of aPWA and COPD experienced higher death rates (73.9 per 1000 person-years (PY)) compared to either COPD or aPWA alone (36.4 per 1000 PY and 31.1 per 1000 PY), respectively. In multivariable-adjusted models, a stronger association between COPD and mortality was noted in the presence compared to the absence of aPWA (HR 95% CI): 1.71 (1.37-2.13) vs. 1.22(1.00-1.49), respectively (interaction P-value = 0.02). Similarly, a stronger association between aPWA and mortality was observed in the presence compared to the absence of COPD (HR 95% CI): 1.66(1.26-2.19) vs. 1.18(1.06-1.31), respectively (interaction P-value = 0.02). Similar higher death rates and mortality risk was observed when spirometry-confirmed COPD and aPWA were present together than in isolation.

CONCLUSION

The concomitant presence of aPWA and COPD leads to a significantly higher mortality rate compared to the presence either COPD or aPWA alone as a clinical variable. P-wave axis, reported routinely on ECG printout, can potentially identify patients with COPD who need intensive control of risk factors and disease management.

Physiological predictors of resting pulmonary hypertension associated with COPD: a retrospective analysis

Background

Resting pulmonary hypertension (PH) is not uncommon in patients with chronic obstructive pulmonary disease (COPD). In the current study, we aimed to identify physiological predictors of resting PH in patients with COPD.

Methods

We retrospectively analyzed data derived from right heart catheterization in sixty-nine stable patients with COPD. Patients were categorized into COPD-PH (n = 33) and COPD-non-PH (n = 36), based on the “6th World Symposium on PH.”

Results

Demographics, forced expiratory volume in 1 s (FEV1), lung volumes, cardiac output, and cardiac index were similar between groups, yet COPD-PH had greater pulmonary vascular resistance (PVR) and lower resting PaO2 (P < 0.05). The proportion of COPD-PH patients did not differ across the range of FEV1 (χ2 = 3.01, P = 0.22). No correlations were found between PVR and the degree of airflow obstruction or resting hyperinflation. Resting PaO2 was the only predictor of both pulmonary artery pressure and PVR.

Conclusions

Increased PVR, in response to arterial hypoxemia or directly induced by tobacco smoking, is likely the key factor that led to resting PH in the current sample of patients with moderate-severe COPD, regardless of the degree of airflow limitation or resting hyperinflation.

Tensions in Taxonomies: Current Understanding and Future Directions in the Pathobiologic Basis and Treatment of Group 1 and Group 3 Pulmonary Hypertension

In the over 100 years since the recognition of pulmonary hypertension (PH), immense progress and significant achievements have been made with regard to understanding the pathophysiology of the disease and its treatment. These advances have been mostly in idiopathic pulmonary arterial hypertension (IPAH), which was classified as Group 1 Pulmonary Hypertension (PH) at the Second World Symposia on PH in 1998. However, the pathobiology of PH due to chronic lung disease, classified as Group 3 PH, remains poorly understood and its treatments thus remain limited. We review the history of the classification of the five groups of PH and aim to provide a state-of-the-art review of the understanding of the pathogenesis of Group 1 PH and Group 3 PH including insights gained from novel high-throughput omics technologies that have revealed heterogeneities within these categories as well as similarities between them. Leveraging the substantial gains made in understanding the genomics, epigenomics, proteomics, and metabolomics of PAH to understand the full spectrum of the complex, heterogeneous disease of PH is needed. Multimodal omics data as well as supervised and unbiased machine learning approaches after careful consideration of the powerful advantages as well as of the limitations and pitfalls of these technologies could lead to earlier diagnosis, more precise risk stratification, better predictions of disease response, new sub-phenotype groupings within types of PH, and identification of shared pathways between PAH and other types of PH that could lead to new treatment targets. © 2023 American Physiological Society. Compr Physiol 13:4295-4319, 2023.

Characterization of pulmonary vascular remodeling and MicroRNA-126-targets in COPD-pulmonary hypertension

BACKGROUND

Despite causing increased morbidity and mortality, pulmonary hypertension (PH) in chronic obstructive pulmonary disease (COPD) patients (COPD-PH) lacks treatment, due to incomplete understanding of its pathogenesis. Hypertrophy of pulmonary arterial walls and pruning of the microvasculature with loss of capillary beds are known features of pulmonary vascular remodeling in COPD. The remodeling features of pulmonary medium- and smaller vessels in COPD-PH lungs are less well described and may be linked to maladaptation of endothelial cells to chronic cigarette smoking (CS). MicroRNA-126 (miR126), a master regulator of endothelial cell fate, has divergent functions that are vessel-size specific, supporting the survival of large vessel endothelial cells and inhibiting the proliferation of microvascular endothelial cells. Since CS decreases miR126 in microvascular lung endothelial cells, we set out to characterize the remodeling by pulmonary vascular size in COPD-PH and its relationship with miR126 in COPD and COPD-PH lungs.

METHODS

Deidentified lung tissue was obtained from individuals with COPD with and without PH and from non-diseased non-smokers and smokers. Pulmonary artery remodeling was assessed by ⍺-smooth muscle actin (SMA) abundance via immunohistochemistry and analyzed by pulmonary artery size. miR126 and miR126-target abundance were quantified by qPCR. The expression levels of ceramide, ADAM9, and endothelial cell marker CD31 were assessed by immunofluorescence.

RESULTS

Pulmonary arteries from COPD and COPD-PH lungs had significantly increased SMA abundance compared to non-COPD lungs, especially in small pulmonary arteries and the lung microvasculature. This was accompanied by significantly fewer endothelial cell markers and increased pro-apoptotic ceramide abundance. miR126 expression was significantly decreased in lungs of COPD individuals. Of the targets tested (SPRED1, VEGF, LAT1, ADAM9), lung miR126 most significantly inversely correlated with ADAM9 expression. Compared to controls, ADAM9 was significantly increased in COPD and COPD-PH lungs, predominantly in small pulmonary arteries and lung microvasculature.

CONCLUSION

Both COPD and COPD-PH lungs exhibited significant remodeling of the pulmonary vascular bed of small and microvascular size, suggesting these changes may occur before or independent of the clinical development of PH. Decreased miR126 expression with reciprocal increase in ADAM9 may regulate endothelial cell survival and vascular remodeling in small pulmonary arteries and lung microvasculature in COPD and COPD-PH.

Chronic moderate hypercapnia suppresses ventilatory responses to acute CO&lt;sub&gt;2&lt;/sub&gt; challenges

Chronic hypercapnia (CH) is a hallmark of chronic lung disease, and CH increases the risk for acute-on-chronic exacerbations leading to greater hypoxemia/hypercapnia and poor health outcomes. However, the role of hypercapnia per se (duration and severity) in determining an individual's ability to tolerate further hypercapnic exacerbations is unknown. Our primary objective herein was to test the hypothesis that mild-to-moderate CH (arterial [Formula: see text] ∼50-70 mmHg) increases susceptibility to pathophysiological responses to severe acute CO₂ challenges. Three groups (GR) of adult female goats were studied during 14 days of exposure to room air (<i>GR 1</i>; control) or 6% inspired CO₂ (<i>GR 2</i>; mild CH), or 7 days of 6% inspired CO₂ followed by 7 days of 8% inspired CO₂ (<i>GR 3</i>; moderate CH). Consistent with previous reports, there were no changes in physiological parameters in <i>GR 1</i> (RA control), but mild CH (<i>GR 2</i>) increased steady-state ventilation and transiently suppressed CO₂/[H⁺] chemosensitivity. Further increasing InCO₂ from 6% to 8% (<i>GR 3</i>) transiently increased ventilation and arterial [H⁺]. Similar to mild CH, moderate CH increased ventilation to levels greater than predicted. However, in contrast to mild CH, acute ventilatory chemosensitivity was suppressed throughout the duration of moderate CH, and the arterial - mixed expired CO₂ gradient became negative. These data suggest that moderate CH limits physiological responses to acute severe exacerbations and provide evidence of recruitment of extrapulmonary systems (i.e., gastric CO₂ elimination) during times of moderate-severe hypercapnia.<b>NEW &amp; NOTEWORTHY</b> Moderate levels of chronic hypercapnia (CH; ∼70 mmHg) in healthy adult female goats elicited similar steady-state physiological adaptations compared with mild CH (∼55 mmHg). However, unlike mild CH, moderate CH chronically suppressed acute CO₂/[H⁺] chemosensitivity and reversed the arterial to mixed expired CO₂ gradient. These findings suggest that moderate CH suppresses vital mechanisms of ventilatory control and recruits additional physiological systems (i.e., gastric CO₂ release) to help buffer excess CO₂.

Effectiveness of pulmonary rehabilitation performed through exercise training for patients with stable COPD: A meta-analysis of randomized controlled trials

Background

The application of pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease (COPD) improves functional capacity and health-related quality of life (HRQoL) at all stages of disease severity. The aim of this study was to determine the effects of PR, performed through exercise training (PR-ET), on functional capacity and HRQoL in patients with stable COPD.

Methods

The meta-analysis was performed by including randomized controlled trials (RCTs) involving patients with stable COPD who participated in different types of PR-ET in which six-minute walk distance (6MWD) and/ or St. George’s Respiratory Questionnaire total scores (SGRQ) were measured. The data search was conducted in December 2020 and January 2021.

Results

The first meta-analysis showed a statistically significant positive effect (MD=31.73m; p<0.00001) of PR-ET on 6MWD. Similarly, the second meta-analysis found a statistically significant favourable effect of pulmonary rehabilitation through exercise training on SGRQ total scores (MD=-8.09; p=0.002).

Conclusions

PR, which includes several different types of exercise training, has a positive effect on the functional capacity and HRQoL of patients with stable COPD. Further studies should be conducted to determine the effects of home-based PR-ET and PR-ET >8 weeks on SGRQ total scores.

Emerging phenotypes of pulmonary hypertension associated with COPD: a field guide

PURPOSE OF REVIEW

Pulmonary hypertension (PH) is a common complication of chronic obstructive lung disease (COPD), but clinical presentation is variable and not always 'proportional' to the severity of the obstructive disease. This review aims to analyze heterogeneity in clinical features of PH-COPD, providing a guide for diagnosis and management according to phenotypes.

RECENT FINDINGS

Recent works have focused on severe PH in COPD, providing insights into the characteristics of patients with predominantly vascular disease. The recently recognized 'pulmonary vascular phenotype', characterized by severe PH and mild airflow obstruction with severe hypoxemia, has markedly worse prognosis and may be a candidate for large trials with pulmonary vasodilators. In severe PH, which might be best described by a pulmonary vascular resistance threshold, there may also be a need to distinguish patients with mild COPD (pulmonary vascular phenotype) from those with severe COPD ('Severe COPD-Severe PH' phenotype).

SUMMARY

Correct phenotyping is key to appropriate management of PH associated with COPD. The lack of evidence regarding the use of pulmonary vasodilators in PH-COPD may be due to the existence of previously unrecognized phenotypes with different responses to therapy. This review offers the clinician caring for patients with COPD and PH a phenotype-focused approach to diagnosis and management, aimed at personalized care.

Relationship Between Episodic Nocturnal Hypercapnia and History of Exacerbations in Patients with Advanced Chronic Obstructive Pulmonary Disease

Purpose

An episodic increase in transcutaneous carbon dioxide pressure (PtcCO₂) is often recognized in patients with advanced chronic obstructive pulmonary disease (COPD) by overnight PtcCO₂ monitoring. This phenomenon, called episodic nocturnal hypercapnia (eNH), mainly corresponds to rapid eye movement (REM) sleep-related hypoventilation. However, it is unclear whether eNH is associated with the frequency of COPD exacerbation. We aimed to investigate whether a relationship exists between COPD exacerbation and eNH.

Patients and Methods

We enrolled consecutive patients with stable, severe, or very severe COPD with a daytime arterial carbon dioxide pressure (PaCO₂) <55.0 mmHg who underwent overnight PtcCO₂ monitoring from April 2013 to January 2017. We retrospectively analyzed the prevalence of eNH and sleep-associated hypoventilation (SH) as defined by the American Academy of Sleep Medicine. Moreover, we compared the relationship between the frequency of COPD exacerbations in the previous year and eNH or SH.

Results

Twenty-four patients were included in this study. The study patients had a mean daytime PaCO₂ and nocturnal PtcCO₂ of 43.3 ± 6.8 mmHg and 42.9 ± 9.6 mmHg, respectively. Six (25.0%) and 11 (45.9%) of the 24 patients met the SH and eNH criteria, respectively. The odds ratios of SH and eNH for at least one annual exacerbation were 1.0 [95% confidence interval (CI): 0.16–6.00] and 11.1 [95% CI: 1.39–87.7], respectively. The odds ratios of SH and eNH for at least two annual exacerbations were 0.3 [95% CI: 0.04–2.64] and 6.6 [95% CI: 1.06–39.4], respectively.

Conclusion

In patients with advanced COPD and a daytime PaCO₂ <55.0 mmHg, eNH may be associated with a history of more frequent exacerbations than SH. Further studies are required to validate these findings.

Association of PM2.5 and PM10 with Acute Exacerbation of Chronic Obstructive Pulmonary Disease at lag0 to lag7: A Systematic Review and Meta-Analysis

This study aimed to conduct a meta-analysis to investigate whether short-term exposure to fine (PM_2.5) and coarse (PM₁₀) particulate matter was associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) hospitalization, emergency room visit, and outpatient visit at different lag values. PubMed, Embase, and the Cochrane Library were searched for relevant papers published up to March 2021. For studies reporting results per 1-µg/m³ increase in PM_2.5, the results were recalculated as per 10-µg/m³ increase. We manually calculated the RRs for these two studies and transferred the RRs to estimate 10 µg/m³ increases in PM_2.5. Automation tools were initially used to remove ineligible studies. Two reviewers independently screened the remaining records and retrieved reports. Twenty-six studies (28 datasets; 7,018,419 patients) were included. There was a significant association between PM_2.5 and AECOPD events on lag0 (ES = 1.01, 95%CI: 1.01-1.02, p < 0.001; I²=88.6%, P_{heterogeneity}<0.001), lag1 (ES = 1.00, 95%CI: 1.00-1.01, p < 0.001; I²=82.5%, P_{heterogeneity}<0.001), lag2 (ES = 1.01, 95%CI: 1.01-1.01, p < 0.001; I²=90.6%, P_{heterogeneity}<0.001), lag3 (ES = 1.01, 95%CI: 1.00-1.01, p < 0.001; I²=88.9%, P_{heterogeneity}<0.001), lag4 (ES = 1.00, 95%CI: 1.00-1.01, p < 0.001; I²=83.7%, P_{heterogeneity}<0.001), and lag7 (ES = 1.00, 95%CI: 1.00-1.00, p < 0.001; I²=0.0%, P_{heterogeneity}=0.743). The subgroup analyses showed that PM_2.5 influenced the rates of hospitalization, emergency room visits, and outpatient visits. Similar trends were observed with PM₁₀. The risk of AECOPD events (hospitalization, emergency room visit, and outpatient visit) was significantly increased with a 10-µg/m³ increment in PM_2.5 and PM₁₀ from lag0 to lag7.List Of Abbreviations: particulate matter (PM_2.5 and PM₁₀); acute exacerbation of chronic obstructive pulmonary disease (AECOPD); Chronic obstructive pulmonary disease (COPD); Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA); Effect sizes [48]; confidence intervals (CIs).

TIMP-1: A Circulating Biomarker for Pulmonary Hypertension Diagnosis Among Chronic Obstructive Pulmonary Disease Patients

Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD) and induces increased mortality among COPD patients. However, there are no blood biomarkers to identify PH in COPD. Here, we investigated whether circulating angiogenic factors and cytokines could serve as (a) biomarker (s) for COPD-PH patients. Using Angiogenesis and Cytokine proteome profile array assay, we measured the level of 36 cytokines and 55 angiogenesis-associated proteins in plasma from four COPD patients with PH (COPD-PH) and four COPD patients without PH (COPD), respectively, tissue inhibitor of metalloproteinase 1 (TIMP-1) and thrombospondin 1(TSP-1) were significantly different between the two groups. Enzyme-linked immunosorbent assay (ELISA) was applied to measured TIMP-1 and TSP-1 in a validation cohort (COPD-PH, n = 28; COPD, n = 18), and TIMP-1 was the only factor that was significantly different between COPD-PH and COPD patients (P < 0.01). Logistic regression analysis demonstrated that elevated TIMP-1 was an independent risk factor for COPD-PH [odds ratio (OR) = 1.258, 95% CI: 1.005–1.574, P < 0.05). Next, we explored the expression level and function of TIMP-1 in human pulmonary arterial smooth muscle cells (hPASMCs) exposed to cigarette smoking extract (CSE, a major etiological factor of COPD). In cultured hPASMCs, CSE treatment increased both TIMP-1 protein level and cell proliferation, and exogenous TIMP-1 (25 ng/mL) treatment inhibited CSE-induced hPASMCs proliferation. Overall, our results indicated that TIMP-1 elevation could serve as a circulating biomarker to diagnose PH among COPD patients, and TIMP-1 elevation in COPD-PH could be adaptive.

Clinical impact of pulmonary hypertension on the outcomes of acute myocardial infarction patients with or without chronic obstructive pulmonary disease

Acute myocardial infarction (AMI) and chronic obstructive pulmonary disease (COPD) are leading global causes of morbidity and mortality. In patients with both of these conditions, the presence of pulmonary hypertension (PH) can further worsen their prognosis. We examined the outcomes of AMI patients with COPD (AMI+COPD) and without COPD (AMI-COPD), depending on the presence or absence of PH.A total of 318 AMI patients with COPD (AMI+COPD cohort) (n = 109) or without COPD (AMI-COPD cohort) (n = 209) were included in this study and were subdivided into 2 groups according to right ventricular systolic pressure (RVSP) level (PH group [RVSP ≥35 mm Hg] and no PH group [RVSP <35 mm Hg]).We investigated characteristics and clinical outcomes in both the AMI-COPD and AMI+COPD cohorts. When investigating in-hospital clinical outcomes, the PH group had a higher proportion of new-onset heart failure (HF) in both cohorts. In the AMI+COPD cohort, however, the PH group had a higher incidence of cardiogenic shock than the no PH group, which was consistent with the result of the post-inverse probability of treatment weighting (IPTW) analysis. When investigating 1-year clinical outcomes, the PH group had higher incidences of a major adverse cardiac event and all-cause mortality in both cohorts. This finding was mainly driven by cardiac death in the AMI-COPD cohort, whereas it was mainly driven by non-cardiac death in the AMI+COPD cohort. After IPTW adjustment, these differences were statistically attenuated such that all variables were similar between both groups.PH may be associated with the development of new-onset HF (in all patients) and cardiogenic shock (in the AMI+COPD cohort). In addition, PH may be also associated with all-cause mortality, although it was statistically attenuated after IPTW adjustment.

Developing a Machine Learning Model to Predict Severe Chronic Obstructive Pulmonary Disease Exacerbations: Retrospective Cohort Study

Background

Chronic obstructive pulmonary disease (COPD) poses a large burden on health care. Severe COPD exacerbations require emergency department visits or inpatient stays, often cause an irreversible decline in lung function and health status, and account for 90.3% of the total medical cost related to COPD. Many severe COPD exacerbations are deemed preventable with appropriate outpatient care. Current models for predicting severe COPD exacerbations lack accuracy, making it difficult to effectively target patients at high risk for preventive care management to reduce severe COPD exacerbations and improve outcomes.

Objective

The aim of this study is to develop a more accurate model to predict severe COPD exacerbations.

Methods

We examined all patients with COPD who visited the University of Washington Medicine facilities between 2011 and 2019 and identified 278 candidate features. By performing secondary analysis on 43,576 University of Washington Medicine data instances from 2011 to 2019, we created a machine learning model to predict severe COPD exacerbations in the next year for patients with COPD.

Results

The final model had an area under the receiver operating characteristic curve of 0.866. When using the top 9.99% (752/7529) of the patients with the largest predicted risk to set the cutoff threshold for binary classification, the model gained an accuracy of 90.33% (6801/7529), a sensitivity of 56.6% (103/182), and a specificity of 91.17% (6698/7347).

Conclusions

Our model provided a more accurate prediction of severe COPD exacerbations in the next year compared with prior published models. After further improvement of its performance measures (eg, by adding features extracted from clinical notes), our model could be used in a decision support tool to guide the identification of patients with COPD and at high risk for care management to improve outcomes.

International Registered Report Identifier (IRRID)

RR2-10.2196/13783

Abnormal pulmonary hemodynamics during exercise is associated with exercise capacity in COPD

BACKGROUND

Pulmonary hypertension (PH) is a frequent complication in COPD and it is associated with decreased exercise capacity and poor prognosis. We hypothesized that even in COPD patients without significant PH at rest, abnormal pulmonary hemodynamics during exercise affect exercise capacity.

METHODS

Consecutive COPD patients with clinically indicated right heart catheterization and resting mean pulmonary arterial pressure (mPAP) < 25 mmHg and age- and sex-matched controls with the same limits of pulmonary hemodynamics but no chronic lung disease who underwent clinical work-up including invasive hemodynamic assessment during exercise, were retrospectively analyzed. Chi-square tests were used to evaluate differences between groups for categorical data and Fisher's exact test or Mann-Whitney-U-tests for continuous variables. Associations were analyzed with Spearman rank correlation tests.

RESULTS

We included n = 26 COPD patients (female/male: 16/10, 66 ± 11 yr, FEV₁: 56 ± 25%predicted) and n = 26 matched controls (FEV₁: 96 ± 22%predicted). At rest, COPD patients presented with slightly increased mPAP (21 (18-23) vs. 17 (14-20) mmHg, p = 0.022), and pulmonary vascular resistance (PVR) [2.5 (1.9-3.0) vs. 1.9 (1.5-2.4) WU, p = 0.020] as compared to controls. During exercise, COPD patients reached significantly higher mPAP [47 (40-52) vs. 38 (32-44) mmHg, p = 0.015] and PVR [3.1 (2.2-3.7) vs. 1.7 (1.1-2.9) WU, p = 0.028] values despite lower peak exercise level [50 (50-75) vs. 100 (75-125) Watt, p = 0.002]. The mPAP/cardiac output slope was increased in COPD vs. controls [6.9 (5.5-10.9) vs. 3.7 (2.4-7.4) mmHg/L/min, p = 0.007] and negatively correlated with both peak oxygen uptake (r = - 0.46, p = 0.007) and 6-min walk distance (r = - 0.46, p = 0.001).

CONCLUSION

Even in the absence of significant PH at rest, COPD patients reveal characteristic abnormalities in pulmonary hemodynamics during exercise, which may represent an important exercise-limiting factor.

High-intensity interval training and pulmonary hemodynamics in COPD with hypoxemia

Background

Exercise is recommended for all patients with COPD. Evidence for its benefit is considerably weaker in the more severe stages of the disease. The aim of this study was to investigate whether high-intensity interval training could improve exercise capacity, pulmonary hemodynamics and cardiac function in patients with severe COPD and hypoxemia.

Methods

Stable patients with COPD GOLD stage III or IV and hypoxemia were included. They underwent extensive cardiopulmonary testing including right heart catheterization, lung function tests, echocardiography and 6-minute walk test before and after completion of 10 weeks of high-intensity interval training performed with supplemental oxygen. Primary endpoint was change in pulmonary artery pressure measured by right heart catheterization.

Results

Ten patients with very severe airflow obstruction, mean FEV1 28.7% predicted and mean FEV1/VC 0.39 completed the exercise programme. Pulmonary artery pressure remained unchanged following the intervention (26,3 mmHg vs. 25,8 mmHg at baseline, p 0.673). Six-minute walk distance improved by a mean of44.8 m (p 0.010), which is also clinically significant. We found marginally improved left ventricular ejection fraction on echocardiography (54.6% vs 59.5%, p 0.046).

Conclusion

High-intensity interval training significantly improved exercise capacity while pulmonary hemodynamics remained unchanged. The improvement may therefore be due to mechanisms other than altered pulmonary artery pressure. The increase in ejection fraction is of uncertain clinical significance. The low number of patients precludes firm conclusions.

Clinical Utility of the Electrocardiographic P-Wave Axis in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND

The vertical P-wave axis on electrocardiography (ECG) is a useful criterion for screening patients with chronic obstructive pulmonary disease (COPD). This study aimed to investigate the clinical characteristics of patients with COPD with a vertical P-wave axis as they have not yet been elucidated.

METHODS

Keio University and its affiliated hospitals conducted an observational COPD cohort study over 3 years. We analyzed 201 patients using ECG and chest computed tomography.

RESULTS

The severity of airflow limitation was higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. Patients with a P-wave axis >75° exhibited significantly higher total COPD assessment test scores and increased St. George's Respiratory Questionnaire total, activity, and impact scores than those with a P-wave axis ≤75°. The incidence of exacerbations over 1 and 3 years was significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. The optimal cutoff for the P-wave axis for a percentage of the predicted forced expiratory volume in 1 s <50% and future exacerbations over 3 years was 70° (the areas under the curve [AUC]: 0.788; sensitivity: 65.3%; specificity: 78.3%) and 79° (AUC: 0.642; sensitivity: 36.7%; specificity: 92.6%). The ratio of the low attenuation area was also significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. However, the ratio of the airway wall area did not differ between the 2 groups.

CONCLUSIONS

Patients with COPD with a vertical P-wave axis exhibited severe airflow limitation and emphysema, a worse health status, and more frequent exacerbation than patients without a vertical P-wave. Detection of the vertical P-wave axis by ECG is beneficial for the management of patients with COPD.

[Chronic obstructive pulmonary disease, sleep-disordered breathing and hypoventilation-Influence on the cardiorenal system]

Comorbidities are frequently observed in patients suffering from pulmonary diseases due to shared risk factors and intricate interactions between various organ systems. This article aims to characterize the effects of selected diseases of the respiratory system on the cardiovascular system and kidneys. Advanced chronic obstructive pulmonary disease (COPD) often leads to a prognostically unfavorable increased pressure in the pulmonary circulation. In this respect treatment of these patients is primarily aimed at the underlying pulmonary disease and targeted treatment of the pulmonary hypertension should only be carried out according to invasive diagnostics and in an individualized manner. So far, the fact that there is a substantial overlap between COPD and heart failure with preserved ejection fraction has been completely ignored, which should be considered in the diagnostic procedure. Obstructive sleep apnea (OSA) has several unfavorable effects on the cardiovascular system and has been identified as an independent risk factor for cardiovascular diseases. The established treatment of OSA with continuous positive airway pressure (CPAP) has been shown to improve daytime sleepiness and the quality of life; however, an effect of CPAP on the occurrence of cardiovascular events, especially in asymptomatic patients, has so far not been demonstrated in randomized trials. Peripheral edema is frequently observed in patients suffering from chronic hypercapnia, which can be explained by several pathophysiological mechanisms, including pulmonary vasoconstriction and a direct effect of the hypercapnia on renal blood flow. Apart from the administration of diuretics, recompensation of such patients always requires treatment of the hypercapnia by noninvasive ventilation.

Patterns of medical care utilization according to environmental factors in asthma and chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use.

RESULTS

The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males.

CONCLUSION

Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.

Comorbidities Associated With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease or COPD is characterized by airflow obstruction, causing respiratory symptoms. There are treatments available for COPD; however, COPD has significant extrapulmonary effects, including well-recognized ones as cardiovascular disease and often underdiagnosed ones as osteoporosis. It is imperative to be aware of these comorbidities to optimize COPD patient care.

Role of Selexipag in Chronic Obstructive Pulmonary Disease (COPD) Patients With Out-of-Proportion Pulmonary Hypertension

Pulmonary hypertension (PH) in patients with chronic obstructive pulmonary disease (COPD) is associated with an increase in the risk of COPD exacerbation, increased hospitalization, and worse survival in this patient population. No specific treatment is available for PH in COPD. However, reported out-of-proportion PH may benefit from a certain type of treatment. This study shows that the use of selexipag in the treatment of out-of-proportion PH in COPD patients was associated with an improvement in functional status evaluated by a six-minute walk test (6MWT) and a mean pulmonary artery pressure at 6 +/- 2 months of treatment.

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.

Group 3 Pulmonary Hypertension: A Review of Diagnostics and Clinical Trials

Group 3 pulmonary hypertension (PH) is a known sequelae of chronic lung disease. Diagnosis and classification can be challenging in the background of chronic lung disease and often requires expert interpretation of numerous diagnostic studies to ascertain the true nature of the PH. Stabilization of the underlying lung disease and adjunctive therapies such as oxygen remain the mainstays of therapy, as there are no Food and Drug Administration-approved therapies for group 3 PH. Referral to PH centers for individualized management and clinical trial enrollment is paramount.

Severe pulmonary hypertension associated with chronic obstructive pulmonary disease: A prospective French multicenter cohort

BACKGROUND

A small proportion of patients with chronic obstructive pulmonary disease (COPD) patients present severe pulmonary hypertension (PH), defined by mean pulmonary artery pressure (mPAP) ≥35 mm Hg measured by right heart catheterization. Little is known about the characteristics of severe PH-COPD. The aim of the study based on a national registry was to describe this phenotype.

METHODS

We prospectively included and followed patients with incident PH-COPD. Clinical, functional, hemodynamic data at inclusion and follow-up were retrieved. Survival assessed by Kaplan-Meier analysis was the primary end-point.

RESULTS

From 2012 to 2016, 99 patients from 13 French centers were included in the study (82 males; median age 66.0 years [interquartile range 62.0-72.0]). At inclusion, most patients had marked dyspnea (55.6% and 22.2% New York Heart Association class III and IV, respectively). During 12 months before inclusion, 42.9% had an exacerbation requiring a hospitalization. Pulmonary function tests showed a moderate obstructive pattern with median (interquartile range) FEV₁ 50.0 [35.0-63.0] % predicted and low diffusing capacity for carbon monoxide, median 20.0 [16.5-30.6] % predicted. The median values for PaO₂ and PaCO₂ on room air were 50.0 [44.8-62.0] and 36.0 [31.1-43.0] mm Hg. Median values of mPAP, pulmonary artery occlusion pressure, cardiac index and pulmonary vascular resistance were 42.0 [37.0-48.0] mm Hg, 11.0 [9.0-14.0] mm Hg, 3.0 [2.4-3.6] L/min/m², and 6.3 [4.2-7.9] WU, respectively. Mean restricted survival was 15.0 [13.9-16.0] months.

CONCLUSIONS

Severe PH-COPD is characterized by moderate airway obstruction but marked dyspnea and marked hypoxemia, low DLCO and high mPAP. This phenotype is associated with poor prognosis.

Physiological and neurochemical adaptations following abrupt termination of chronic hypercapnia in goats

Chronic hypercapnia (CH) is a hallmark of respiratory diseases such as chronic obstructive pulmonary disease. In such patients, mechanical ventilation is often used to restore normal blood-gas homeostasis. However, little is known regarding physiological changes and neuroplasticity within physiological control networks after termination of CH. Utilizing our goat model of increased inspired CO₂-induced CH, we determined whether termination of CH elicits time-dependent physiological and neurochemical changes within brain stem sites of physiological control. Thirty days of CH increased [Formula: see text] (+15 mmHg) and steady-state ventilation (SS V̇i; 283% of control). Within 24 h after terminating CH, SS V̇i, blood gases, arterial [H⁺], and most physiological measurements returned to control. However, the acute ventilatory chemoreflex (ΔV̇i/Δ[H⁺]) was greater than control, and measured SS V̇i exceeded ventilation predicted by arterial [H⁺] and ΔV̇i/Δ[H⁺]. Potentially contributing to these differences were increased excitatory neuromodulators serotonin and norepinephrine in the nucleus tractus solitarius, which contrasts with minimal changes observed at 24 h and 30 days of hypercapnia. Similarly, there were minimal changes found in markers of neuroinflammation and glutamate receptor-dependent neuroplasticity upon termination of CH, which were previously increased following 24 h of hypercapnia. Thus, following termination of CH: 1) ventilatory, renal, and other physiological functions rapidly return to control; 2) neuroplasticity within the ventilatory control network may contribute to the difference between measured vs. predicted ventilation and the elevation in the acute ventilatory [H⁺] chemoreflex; and 3) neuroplasticity is fundamentally distinct from acclimatization to CH.NEW & NOTEWORTHY In healthy adult goats, steady-state ventilation and most physiological measures return to control within 24 h after termination of chronic hypercapnia (CH). However, the acute [H⁺] chemoreflex is increased, and measured ventilation exceeds predicted ventilation. At 24 h of recovery, excitatory neuromodulators are above control, but other measured markers of neuroplasticity are unchanged from control. Our data suggest that CH elicits persistent physiological and neurochemical changes for up to 24 h after termination of CH.

The Challenge to Decide between Pulmonary Hypertension Due to Chronic Lung Disease and PAH with Chronic Lung Disease

Chronic lung diseases are strongly associated with pulmonary hypertension (PH), and even mildly elevated pulmonary arterial pressures are associated with increased mortality. Chronic obstructive pulmonary disease (COPD) is the most common chronic lung disease, but few of these patients develop severe PH. Not all these pulmonary pressure elevations are due to COPD, although patients with severe PH due to COPD may represent the largest subgroup within patients with COPD and severe PH. There are also patients with left heart disease (group 2), chronic thromboembolic disease (group 4, CTEPH) and pulmonary arterial hypertension (group 1, PAH) who suffer from COPD or another chronic lung disease as co-morbidity. Because therapeutic consequences very much depend on the cause of pulmonary hypertension, it is important to complete the diagnostic procedures and to decide on the main cause of PH before any decision on PAH drugs is made. The World Symposia on Pulmonary Hypertension (WSPH) have provided guidance for these important decisions. Group 2 PH or complex developmental diseases with elevated postcapillary pressures are relatively easy to identify by means of elevated pulmonary arterial wedge pressures. Group 4 PH can be identified or excluded by perfusion lung scans in combination with chest CT. Group 1 PAH and Group 3 PH, although having quite different disease profiles, may be difficult to discern sometimes. The sixth WSPH suggests that severe pulmonary hypertension in combination with mild impairment in the pulmonary function test (FEV1 > 60 and FVC > 60%), mild parenchymal abnormalities in the high-resolution CT of the chest, and circulatory limitation in the cardiopulmonary exercise test speak in favor of Group 1 PAH. These patients are candidates for PAH therapy. If the patient suffers from group 3 PH, the only possible indication for PAH therapy is severe pulmonary hypertension (mPAP ≥ 35 mmHg or mPAP between 25 and 35 mmHg together with very low cardiac index (CI) < 2.0 L/min/m²), which can only be derived invasively. Right heart catheter investigation has been established nearly 100 years ago, but there are many important details to consider when reading pulmonary pressures in spontaneously breathing patients with severe lung disease. It is important that such diagnostic procedures and the therapeutic decisions are made in expert centers for both pulmonary hypertension and chronic lung disease.

[Differential Diagnosis of Pulmonary Hypertension Using the Example of Collagenosis-associated PAH in the Context of Chronic Lung and Left Heart Disease]

Pulmonary hypertension (PH) can be diagnosed in the context of connective tissue diseases (CTD) as well as in elderly patients with multiple comorbidities. A correct clinical differential diagnosis and classification is essential before adequate therapeutic decisions can be made. Differential diagnosis of PH in CTD comprises associated pulmonary arterial hypertension (APAH), group 2 or 3 PH (PH arising from left heart or chronic lung disease), chronic thromboembolic PH (PH) and group 5 (e. g. in the context of terminal renal insufficiency). This is also true of elderly patients in whom the decision has to be made if the increasing number of coincident diseases lead to PH or have to be interpreted as comorbidities. In this manuscript, the differential diagnosis of PH is elucidated, focusing on CTD, in the context of left heart disease and chronic lung disease. Furthermore, criteria are presented facilitating an objective approach in this context.

The five-repetition sit-to-stand test is a predictive factor of severe exacerbations in COPD

Background:

Although the six-minute-walk test (6MWT) has been used to predict chronic obstructive pulmonary disease (COPD) exacerbations, additional research is necessary to identify more rapid, simpler tests that are directly associated with exacerbations, such as the five-repetition sit-to-stand (5STS) test and 4-m gait speed (4MGS) test.

Aims:

To determine the ability of the 5STS and 4MGS tests in predicting severe exacerbations in stable COPD over the following year, and to assess the ability of the best prognostic test to identify patients at high risk of hospital admission correctly.

Methods:

This prospective study included 137 patients with stable COPD. Multiple logistic regression models were constructed to assess whether the 6MWT, 5STS, and 4MGS tests were associated with severe exacerbations in the year following the test. Receiver-operating characteristic curves and the area under the curve (AUC) were evaluated to determine the accuracy of each test for identifying patients with severe exacerbations.

Results:

Scores of <350 m for the 6WMT and ⩽2 for the 5STS test were associated with severe exacerbations in the model adjusted for age and the number of exacerbations in the previous year. The 5STS test and the 6MWT had very similar predictive and discriminative abilities. Odds ratios were 3.20 (95% confidence interval [CI] 1.14–8.96) and 3.84 (95% CI 1.14–12.94) and AUCs were 0.793 (95% CI 0.704–0.882) and 0.783 (95% CI 0.686–0.879), respectively.

Conclusions:

The 5STS test predicted the risk of severe exacerbation within the following year among patients with COPD. The 5STS test could replace the 6MWT for identifying patients at high risk of hospital admission.

TRPV1 genetic polymorphisms and risk of COPD or COPD combined with PH in the Han Chinese population

COPD is a common chronic disease with genetic predisposition. TRPV1 is mainly expressed in peripheral neuron which widely exists in entire respiratory tract. In present study, we aimed to study the relationship between single nucleotide polymorphisms (SNPs) of transient receptor potential vanilloid-1 (TRPV1) and the risk of chronic obstructive pulmonary disease (COPD) or COPD combined with pulmonary hypertension (PH) in Chinese Han population. A total of 1019 individuals, including 506 healthy volunteers and 513 COPD patients (150 patients combined with PH among them) were recruited in this study. Genomic DNA were extracted and sequenced. Genotype and allele frequencies of the TRPV1 SNPs among COPD, COPD combined with PH and control groups were compared. Then, the association of TRPV1 SNPs and smoking status were analyzed. Genotype frequencies of SNP rs3744683 had a significant difference in COPD patients with PH patients compared with control (p = 0.006) or COPD patients without PH patients (p = 0.016). Likewise, SNP rs3744683 was remarkedly associated with the risk of COPD (p = 0.004) in current-smoker groups which phenomenon was not observed in nonsmoker or former-smoker groups. Compared with the control group, there was a significant difference for the distribution of SNP rs4790521 alleles in the COPD group (p = 0.041). For further, logical regression analysis showed that SNP rs3744683 genotype of “TC” was a protective factor for PH in COPD patients compared with the genotype of “TT” (OR = 0.364, 95%CI = 0.159–0.829, p = 0.016). Our findings firstly revealed the relevance between TRPV1 SNPs and the risk for COPD/COPD combined with PH.

COPD smokers who switched to e-cigarettes: health outcomes at 5-year follow up

Background and Aims:

The long-term health effects of the use of electronic cigarettes (ECs) in patients with chronic obstructive pulmonary disease (COPD) are largely unexplored. We present findings from a 5-year prospective assessment of respiratory parameters in a cohort of COPD patients who substantially reduced conventional smoking or achieved abstinence by switching to ECs.

Methods:

Patients were evaluated prospectively for their measurements of respiratory exacerbations, spirometric indices, quality of life using the COPD assessment tool (CAT), 6-min walk distance (6MWD), as well as conventional cigarette consumption. Baseline measurements prior to switching to EC use were compared with follow-up visits at 12-, 24-, 48- and 60-months. Age- and sex-matched COPD patients reporting to be regular smokers (not using ECs) were the reference group for the analysis.

Results:

Complete data were available from 39 patients. Those in the EC user group achieved a marked decline in cigarette smoking or abstinence. COPD EC users had a significant diminution in COPD exacerbations; with the mean (±SD) exacerbation rate falling from 2.3 (±0.9) at baseline to 1.1 (±1.0) at 5 years (p < 0.001), whereas no significant changes were observed in the control group.

Significant and constant improvements in lung function, CAT scores and 6MWD were reported in the EC user group over the 5-year observation period compared with the reference group (p < 0.05).

Conclusion:

The present study suggests that EC use may ameliorate objective and subjective COPD outcomes, and that the benefits gained appear to persist long term. EC use for abstinence and smoking reduction may ameliorate some of the harm resulting from tobacco smoking in COPD patients.

Two chair test: a substitute of 6 min walk test appear cardiopulmonary reserve specific

Background

A simple and efficient exercise test possible in a small space is welcome to supplement 6 min walk test (6MWT) that demands a 100 feet corridor to perform.

Methods

The proposed two chair test (2CT) makes a person to sit and move five times between two chairs placed face to face at 5 feet apart and note the changes in pulse-rate (PR) and arterial oxygen saturation (SpO₂) at every 10 s for 2 min after that. Comparison of the post-exercise measurements (PR and SpO₂) with a repeat performance in same patients was done for reproducibility and doing the same after 6MWT and 2CT in another set of patients was meant for for acceptability. The statistical analysis was made on moment to moment change, mean maximal difference and mean cumulative difference for the measurements using p value, z-score, r value and principal component analysis (PCA).

Findings

A total of 40 and 60 volunteers were included for testing reproducibility and acceptability. On both the sets, the difference in most of comparisons between the measured variable (PR and SpO₂) showed the p values remaining insignificant (>0.05), and z-score being <1 SD of the corresponding other and the correlation coefficients (r) remaining excellent (>0.9). Furthermore, the PCA shows complete overlapping. The post-exercise changes did not corelate the walking distance in 6MWT.

Interpretation

The proposed 2CT demands small space and appears reproducible and comparable with 6MWT in terms of its post-exercise impact on PR and SpO₂. This novel test also appears more of cardiopulmonary reserve specific.

Association Between Systemic and Pulmonary Vascular Dysfunction in COPD

Introduction

In chronic obstructive pulmonary disease (COPD), endothelial dysfunction and stiffness of systemic arteries may contribute to increased cardiovascular risk. Pulmonary vascular disease (PVD) is frequent in COPD. The association between PVD and systemic vascular dysfunction has not been thoroughly evaluated in COPD.

Methods

A total of 108 subjects were allocated into four groups (non-smoking controls, smoking controls, COPD without PVD and COPD with PVD). In systemic arteries, endothelial dysfunction was assessed by flow-mediated dilation (FMD) and arterial stiffness by pulse wave analysis (PWA) and pulse wave velocity (PWV). PVD was defined by a mean pulmonary artery pressure (PAP) ≥25 mmHg at right heart catheterization or by a tricuspid regurgitation velocity >2.8 m/s at doppler echocardiography. Biomarkers of inflammation and endothelial damage were assessed in peripheral blood.

Results

FMD was lower in COPD patients, with or without PVD, compared to non-smoking controls; and in patients with COPD and PVD compared to smoking controls. PWV was higher in COPD with PVD patients compared to both non-smoking and smoking controls in a model adjusted by age and the Framingham score; PWV was also higher in patients with COPD and PVD compared to COPD without PVD patients in the non-adjusted analysis. FMD and PWV correlated significantly with forced expiratory volume in the first second (FEV₁), diffusing capacity for carbon monoxide (DL_CO) and systolic PAP. FMD and PWV were correlated in all subjects.

Discussion

We conclude that endothelial dysfunction of systemic arteries is common in COPD, irrespective if they have PVD or not. COPD patients with PVD show increased stiffness and greater impairment of endothelial function in systemic arteries. These findings suggest the association of vascular impairment in both pulmonary and systemic territories in a subset of COPD patients.

Comorbidities and Readmissions in Survivors of Acute Hypercapnic Respiratory Failure

Chronic obstructive pulmonary disease (COPD) is defined by chronic airflow obstruction, but is presently considered as a complex, heterogeneous, and multicomponent disease in which comorbidities and extrapulmonary manifestations make important contributions to disease expression. COPD-related hospital readmission. In particular frequent intensive care unit (ICU) readmissions for exacerbations represent a major challenge and place a high burden on patient outcomes and health-related quality of life, as well as on the healthcare system.In this narrative review, we first address major and often undiagnosed comorbidities associated with COPD that could have an impact on hospital readmission after an index ICU admission for acute hypercapnic respiratory failure. Some guidance for treatment is discussed. Second, we present predictors of hospital and ICU readmission and discuss various strategies to reduce such events.There is a strong rationale to detect and treat major comorbidities early after index ICU admission for acute hypercapnic respiratory failure. It still remains unclear, however, if a comprehensive and holistic approach to comorbidities in frail patients surviving hypercapnic respiratory failure can efficiently reduce the readmission rate.