Programmed Follow-up and Quality Control of Treatment Techniques Enhance Chronic Thromboembolic Pulmonary Hypertension Management: Lessons From a Multidisciplinary Team.

BACKGROUND AND OBJECTIVES: The recent developments in chronic thromboembolic pulmonary hypertension (CTEPH) are emphasizing the multidisciplinary team. We report on the changes in clinical practice following the development of a multidisciplinary team, based on our 7 years of experience. METHODS: Multidisciplinary team was established in 2015 offering both balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) with technical upgrades by internal and external expertise. For operable cases, PEA was recommended as the primary treatment modality, followed by pulmonary angiography and right heart catheterization after 6 months to evaluate treatment effect and identify patients requiring further BPA. For patients with inoperable anatomy or high surgical risk, BPA was recommended as the initial treatment modality. Patient data and clinical outcomes were closely monitored. RESULTS: The number of CTEPH treatments rapidly increased and postoperative survival improved after team development. Before the team, 38 patients were treated by PEA for 18 years; however, 125 patients were treated by PEA or BPA after the team for 7 years. The number of PEA performed was 64 and that of BPA 342 sessions. World Health Organization functional class I or II was achieved in 93% of patients. The patients treated with PEA was younger, male dominant, higher pulmonary artery pressure, and smaller cardiac index, than BPA-only patients. In-hospital death after PEA was only 1 case and none after BPA. CONCLUSIONS: The balanced development of BPA and PEA through a multidisciplinary team approach proved synergistic in increasing the number of actively treated CTEPH patients and improving clinical outcomes.

Clinical characteristics of chronic obstructive pulmonary disease patients with superoptimal peak inspiratory flow rate.

Characteristics of chronic obstructive pulmonary disease (COPD) patients with superoptimal peak inspiratory flow rates (PIFR) has not been thoroughly investigated. This study aimed to compare the characteristics between COPD patients with superoptimal PIFR and those with optimal and sub-optimal PIFR. PIFR was measured using In-Check DIAL G16 and categorized into sub-optimal (PIFR lower than that required by the patient's device), optimal, and superoptimal (peak PIFR ≥ 90 L/min). Considering COPD patients with sub-optimal PIFR as the reference group, analyses were performed to identify PIFR-related factors. Subgroup analysis was performed according to the forced expiratory volume in 1 s (FEV1) % of the predicted value (%pred). Among 444 post-bronchodilator-confirmed COPD patients from seven tertiary hospitals in South Korea, 98, 223, and 123 were classified into the sub-optimal, optimal, and superoptimal PIFR groups, respectively. The superoptimal PIFR group were younger, had an increased proportion of males, a higher body mass index, lowest number of comorbidities and less frequent exacerbation in the previous year, as well as the highest forced vital capacity %pred. The adjusted odds ratio for frequent exacerbation in the previous year was lower in the superoptimal PIFR group than in the sub-optimal PIFR group and was more pronounced in patients with an FEV1%pred of < 70%. COPD patients with superoptimal PIFR have clinical characteristics different from those patients with the sub-optimal and optimal PIFR. Having a high inspiratory flow may be a favorable trait in COPD.

Efficacy and safety of mixture of ivy leaf extract and coptidis rhizome in the treatment of acute bronchitis: multicenter, randomized, double-blinded, active-controlled, parallel, therapeutic confirmatory clinical trial.

BACKGROUND: Acute bronchitis is the most common respiratory disease. Mixture of Ivy Leaf Extract and Coptidis rhizome syrup has shown good treatment efficacy against chronic bronchitis and acute respiratory infections. This study aimed to evaluate the efficacy and safety of Mixture of Ivy Leaf Extract and Coptidis rhizome compared with those of Pelargonium sidoides extract, for the treatment of acute bronchitis. METHODS: We performed a multicenter, randomized, double-blind, active-controlled, parallel phase III study in 220 patients with acute bronchitis. The participants were offered either Mixture of Ivy Leaf Extract and Coptidis rhizome syrup (AGS) and placebo of P. sidoides tablet or placebo syrup and active tablet of P. sidoides (AGU) for 7 days. The primary endpoint was the change in the Bronchitis Severity Score (BSS) from the baseline visit (visit 2) to day 7 (visit 3). RESULTS: For the primary outcome, there was no significant difference in the change of total BSS between visits 2 and 3 (-4.10 ± 1.93 vs. -4.24 ± 1.85, p = 0.5125), and since the upper limit of the confidence interval (1.00) was smaller than the predetermined non-inferiority margin (1.17), it was confirmed that the AGS group was non-inferior to the AGU group. The changes in each symptom in the BSS between visits 2 and 3 also showed no significant differences. The overall improvement rate measured by the investigator (91.7 vs. 89.7%; p = 0.3506) and the satisfaction rate of the participants at visit 3 also showed no significant differences (97.2 vs. 94.4%; p = 0.4388). Regarding safety issues, adverse reactions were noted in both groups similarly, with no serious adverse events (4.55 vs. 3.64%, p > 0.999). CONCLUSION: Mixture of Ivy Leaf Extract and Coptidis rhizome syrup is as effective and safe as P. sidoides in controlling symptoms of acute bronchitis.

The association of blood eosinophil counts and FEV1 decline: a cohort study.

BACKGROUND: Accelerated lung function decline is characteristic of COPD. However, the association between blood eosinophil counts and lung function decline, accounting for current smoking status, in young individuals without prevalent lung disease is not fully understood. METHODS: This is a cohort study of 629 784 Korean adults without COPD or a history of asthma at baseline who participated in health screening examinations including spirometry and differential white blood cell counts. We used a linear mixed-effects model to estimate the annual change in forced expiratory volume in 1 s (FEV1) (mL) by baseline blood eosinophil count, adjusting for covariates including smoking status. In addition, we performed a stratified analysis by baseline and time-varying smoking status. RESULTS: During a mean follow-up of 6.5 years (maximum 17.8 years), the annual change in FEV1 (95% CI) in participants with eosinophil counts <100, 100-199, 200-299, 300-499 and ≥500 cells·µL-1 in the fully adjusted model were -23.3 (-23.9--22.7) mL, -24.3 (-24.9--23.7) mL, -24.8 (-25.5--24.2) mL, -25.5 (-26.2--24.8) mL and -26.8 (-27.7--25.9) mL, respectively. When stratified by smoking status, participants with higher eosinophil count had a faster decline in FEV1 than those with lower eosinophil count in both never- and ever-smokers, which persisted when time-varying smoking status was used. CONCLUSIONS: Higher blood eosinophil counts were associated with a faster lung function decline among healthy individuals without lung disease, independent of smoking status. The findings suggest that higher blood eosinophil counts contribute to the risk of faster lung function decline, particularly among younger adults without a history of lung disease.

Lack of Association between Inhaled Corticosteroid Use Based on the Exhaled Nitric Oxide and Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) is known to useful biomarker for detecting eosinophilic airway inflammation. However, there is a lack of evidence regarding the role of FeNO in chronic obstructive pulmonary disease (COPD). We aimed to assess whether elevated FeNO and its impact on treatment change into an inhaled corticosteroid (ICS)-containing regimen and association with acute exacerbation (AE) in patients with COPD. METHODS: We retrospectively analyzed 107 COPD patients without a history of asthma from March 2016 to December 2019. The patients whose FeNO value was more than 50 parts per billion (ppb) were defined into the high FeNO group. Multivariable analysis with logistic regression was used to identify factors associated with AE in COPD. RESULTS: The median FeNO value was 32 ppb (interquartile range, 19 to 45) and 34 (20.0%) patients were classified as high FeNO group (median 74 ppb). In the high FeNO group, changes in inhaler treatment into an ICS-containing regimen occurred in 23 of 34 patients after the measurement of FeNO. In multivariate analysis, high FeNO was not a contributing factor for AE, but only the high blood eosinophil count (≥300 cells/µL) was associated with AE (adjusted odds ratio, 2.63; 95% confidence interval, 1.01 to 6.91; p=0.049). CONCLUSION: High FeNO value had a significant impact on the prescription of ICSs in COPD patients, but it did not show a significant association with AE either on its own or with changes in treatment.

Preoperative DLco and FEV1 are correlated with postoperative pulmonary complications in patients after esophagectomy.

Limited information is available regarding the association between preoperative lung function and postoperative pulmonary complications (PPCs) in patients with esophageal cancer who undergo esophagectomy. This is a retrospective cohort study. Patients were classified into low and high lung function groups by the cutoff of the lowest fifth quintile of forced expiratory volume in 1 s (FEV1) %predicted (%pred) and diffusing capacity of the carbon monoxide (DLco) %pred. The PPCs compromised of atelectasis requiring bronchoscopic intervention, pneumonia, and acute lung injury/acute respiratory distress syndrome. Modified multivariable-adjusted Poisson regression model using robust error variances and inverse probability treatment weighting (IPTW) were used to assess the relative risk (RR) for the PPCs. A joint effect model considered FEV1%pred and DLco %pred together for the estimation of RR for the PPCs. Of 810 patients with esophageal cancer who underwent esophagectomy, 159 (19.6%) developed PPCs. The adjusted RR for PPCs in the low FEV1 group relative to high FEV1 group was 1.48 (95% confidence interval [CI] = 1.09-2.00) and 1.98 (95% CI = 1.46-2.68) in the low DLco group relative to the high DLco group. A joint effect model showed adjusted RR of PPCs was highest in patients with low DLco and low FEV1 followed by low DLco and high FEV1, high DLco and low FEV1, and high DLco and high FEV1 (Reference). Results were consistent with the IPTW. Reduced preoperative lung function (FEV1 and DLco) is associated with post-esophagectomy PPCs. The risk was further strengthened when both values decreased together.

Impact of smoking reduction on lung cancer risk in patients with COPD who smoked fewer than 30 pack-years: a nationwide population-based cohort study.

BACKGROUND: The effects of smoking reduction on the incidence of lung cancer in patients with chronic obstructive pulmonary disease (COPD) are not well known. This study aimed to investigate the effects of changes in smoking habits after COPD diagnosis on lung cancer development in patients who smoked less than 30 pack-years. METHODS: This nationwide retrospective cohort study included 16,832 patients with COPD who smoked less than 30 pack-years at the time of COPD diagnosis. Based on changes in smoking habits in the health screening examination data, smokers were categorized into three groups: quitters, reducers, and sustainers. The primary outcome was the risk of lung cancer development, which was estimated using the Cox proportional hazards model. We also modelled the amount of smoking reduction as a continuous variable. RESULTS: During a median follow-up of 4 years, the cumulative incidence of lung cancer was the highest among sustainers, followed by reducers and quitters. Compared with sustainers, reducers (adjusted HR 0.74, 95% CI:0.56-0.98) and quitters (adjusted HR 0.78, 95% CI:0.64-0.96) had a significantly lower risk of lung cancer. Incidence of lung cancer showed a decreasing trend with a decreasing amount of smoking (P for linearity < 0.01). CONCLUSIONS: In patients with COPD who smoked less than 30 pack-years, smoking reduction and cessation lowered the risk of lung cancer.

Association of resistance training and moderate-to-vigorous physical activity with clinical outcomes in men with airflow limitation: a nationwide population-based study.

Aerobic moderate-to-vigorous physical activity (MVPA) is recommended for individuals with chronic diseases. However, the association between resistance training (RT) in addition to moderate to vigorous physical activity (MVPA) and sleep duration, as well as respiratory symptoms, in patients with chronic obstructive pulmonary disease has not been thoroughly investigated. This population-based cross-sectional study used data from the Korea National Health and Nutrition Examination Survey between 2014 and 2019. A total of 61,754 individuals were identified and men with airflow limitation (FEV1/FVC < 0.7) who engaged in aerobic MVPA were selected (n = 794). Weighted percentages and odds ratio (OR) of sleep problems (≤ 5 or ≥ 9 h), chronic cough, and chronic sputum were estimated. A multivariate-adjusted complex sample logistic regression model was used to calculate ORs and 95% confidence intervals (CI). Subgroup analyses were conducted using the forced expiratory volume (FEV1) % of the predicted value (%pred) ≥ 80 vs. < 80. The percentages of sleep problems, chronic cough, and chronic sputum production were lower in men who underwent aerobic MVPA + RT than in those who underwent aerobic MVPA alone. The multivariable-adjusted OR of sleep problems was 0.44 (95% CI 0.25-0.77) in individuals undergoing aerobic MVPA + RT compared to aerobic MVPA alone. The ORs of chronic cough and sputum were 0.35 (95% CI 0.13-0.94) and 0.51 (95% CI 0.30-0.87), respectively. These associations were only significant in individuals with FEV1 < 80% pred. Compared with aerobic MVPA alone, aerobic MVPA + RT was associated with appropriate sleep duration and a decrease in chronic cough and sputum in male with airflow limitation. This was more pronounced in individuals with a FEV1 < 80% pred.

Longitudinal BMI change and outcomes in Chronic Obstructive Pulmonary Disease: a nationwide population-based cohort study.

BACKGROUND: The association between longitudinal body mass index (BMI) change and clinical outcomes in patients with chronic obstructive pulmonary disease (COPD) has not fully investigated. METHODS: This retrospective cohort study included 116,463 COPD patients aged ≥ 40, with at least two health examinations, one within 2 years before and another within 3 years after COPD diagnosis (January 1, 2014, to December 31, 2019). Associations between BMI percentage change with all-cause mortality, primary endpoint, and initial severe exacerbation were assessed. RESULTS: BMI decreased > 5% in 14,728 (12.6%), while maintained in 80,689 (69.2%), and increased > 5% in 21,046 (18.1%) after COPD diagnosis. Compared to maintenance group, adjusted hazard ratio (aHR) for all-cause mortality was 1.70 in BMI decrease group (95% CI:1.61, 1.79) and 1.13 in BMI increase group (95% CI:1.07, 1.20). In subgroup analysis, decrease in BMI showed a stronger effect on mortality as baseline BMI was lower, while an increase in BMI was related to an increase in mortality only in obese COPD patients with aHRs of 1.18 (95% CI: 1.03, 1.36). The aHRs for the risk of severe exacerbation (BMI decrease group and increase group vs. maintenance group) were 1.30 (95% CI:1.24, 1.35) and 1.12 (95% CI:1.07, 1.16), respectively. CONCLUSIONS: A decrease in BMI was associated with an increased risk of all-cause mortality in a dose-dependent manner in patients with COPD. This was most significant in underweight patients. Regular monitoring for weight loss might be an important component for COPD management.

Usefulness of cardiopulmonary exercise test combined with exercise stress echocardiography in mild chronic thromboembolic pulmonary disease.

PURPOSE: Chronic thromboembolic pulmonary disease (CTEPD) can lead to exercise limitations even without right ventricular (RV) dysfunction or pulmonary hypertension at rest. Combining exercise stress echocardiography with cardiopulmonary exercise testing (ESE-CPET) for RV function and pressure changes combined measuring overall function may be useful for CTEPD evaluation. This study aims to investigate CPET and ESE results to elucidate the mechanisms of exercise limitation in mild CTEPD cases. METHODS: Among our CTEPD registry, 50 patients who performed both right heart catheterization data of mild disease (less than 30 mm Hg of mean pulmonary arterial pressure (mPAP)) and ESE-CPET were enrolled. Echocardiography and CPET-derived parameters were compared with hemodynamic parameters measured through right heart catheterization. RESULTS: Peak VO2 (maximal oxygen consumption) was decreased in overall population (71.3 ± 16.3% of predictive value). Peak VO2 during exercise was negatively correlate with mPAP and pulmonary vascular resistance at rest. A substantial increase in RV systolic pressure (RVSP) was observed during exercise (RVSP: pre-exercise 37.2 ± 11.8 mm Hg, postexercise 64.3 ± 24.9 mm Hg, p-value < .001). Furthermore, RV function deteriorated during exercise when compared to the baseline (RV fractional area change: 31.5 ± 10.0% to 37.8 ± 7.0%, p-value < .001; RV global longitudinal strain: -17.1 ± 4.2% to -17.7 ± 3.3%, p-value < .001) even though basal RV function was normal. While an excessive increase in RVSP during exercise was noticed in both groups, dilated RV and RV dysfunction during exercise were demonstrated only in the impaired exercise capacity group. CONCLUSION: CTEPD patients with mild PH or without PH exhibited limited exercise capacity alongside an excessive increase in RVSP during exercise. Importantly, RV dysfunction during exercise was significantly associated with exercise capacity. ESE-CPET could aid in comprehending the primary cause of exercise limitation in these patients.

Prospective study investigating hypofractionated proton beam therapy in patients with inoperable early stage non-small cell lung cancer.

Purpose: To report the results of hypofractionated proton beam therapy (PBT) for the treatment of early stage lung cancer in patients not suitable for surgical resection. Methods: Data from 27 adult patients, who were diagnosed with inoperable cT1-3N0 non-small cell lung cancer (NSCLC) between March 2018 and August 2020, were analyzed. PBT was prescribed as 64 Cobalt Grey equivalents delivered in 8 fractions (Sumitomo, Japan). The primary endpoint was local control; secondary endpoints included overall survival, quality of life, and grade ≥3 toxicity. Results: The median follow-up was 28.9 months (range, 1.1-62.1 months). During follow-up, 13 (48.1%) patients experienced disease progression, including local progression in 7. Two-year local control rates were 73.5%, 85.7% for T1, and 61.4% for T2-3. The worse local control rate was observed in those with large clinical target volumes (≥ 47.5 cc) and heavy smoking history (≥30 pack-years). The two-year overall survival rate was 76.5%. Grade 3 radiation-related toxicities were observed in 2 (7.4%) patients. In the European Organization for Research and Treatment of Cancer Quality of Life Core 30 results, the global score did not change significantly from baseline. However, dyspnea score increased from 19.8 before PBT to 33.3 at 4 months' post-PBT (p=0.047) and was maintained until 13 months (p=0.028). Conclusion: Hypofractionated PBT was a safe treatment option for inoperable early stage NSCLC and appeared to be appropriate for small tumor volumes. However, local control for larger tumors requires further improvement.

Machine learning model for circulating tumor DNA detection in chronic obstructive pulmonary disease patients with lung cancer.

Background: Patients with chronic obstructive pulmonary disease (COPD) have a high risk of developing lung cancer. Due to the high rates of complications from invasive diagnostic procedures in this population, detecting circulating tumor DNA (ctDNA) as a non-invasive method might be useful. However, clinical characteristics that are predictive of ctDNA mutation detection remain incompletely understood. This study aimed to investigate factors associated with ctDNA detection in COPD patients with lung cancer. Methods: Herein, 177 patients with COPD and lung cancer were prospectively recruited. Plasma ctDNA was genotyped using targeted deep sequencing. Comprehensive clinical variables were collected, including the emphysema index (EI), using chest computed tomography. Machine learning models were constructed to predict ctDNA detection. Results: At least one ctDNA mutation was detected in 54 (30.5%) patients. After adjustment for potential confounders, tumor stage, C-reactive protein (CRP) level, and milder emphysema were independently associated with ctDNA detection. An increase of 1% in the EI was associated with a 7% decrease in the odds of ctDNA detection (adjusted odds ratio =0.933; 95% confidence interval: 0.857-0.999; P=0.047). Machine learning models composed of multiple clinical factors predicted individuals with ctDNA mutations at high performance (AUC =0.774). Conclusions: ctDNA mutations were likely to be observed in COPD patients with lung cancer who had an advanced clinical stage, high CRP level, or milder emphysema. This was validated in machine learning models with high accuracy. Further prospective studies are required to validate the clinical utility of our findings.

Predictive Role of White Blood Cell Differential Count for the Development of Acute Exacerbation in Korean Chronic Obstructive Pulmonary Disease.

Purpose: Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by chronic inflammation. Acute exacerbation of COPD (AECOPD) manifests as acute worsening of respiratory symptoms and is associated with high morbidity and mortality. The aim of the present study was to evaluate the predictive value of white blood count (WBC) and its derived inflammatory biomarkers for AECOPD. Methods: From the Korean COPD Subgroup Study cohort, a prospective and multicenter observational study, 826 patients who had baseline complete blood count (CBC) and 3-year AECOPD data were included. Follow-up CBC data at 1 (n = 385), 2 (n = 294), and 3 (n = 231) years were collected for available patients. The primary outcome was the occurrence of AECOPD at 3 years. The risk of AECOPD was evaluated using a binary logistic analysis. Results: The cumulative incidences of 12-, 24-, and 36-month AECOPD were 47.6%, 60.5%, and 67.6%, respectively. Patients with AECOPD at 3 years had higher baseline WBC counts, neutrophil counts, neutrophil/lymphocyte ratio (NLR), and neutrophil/monocyte ratio than those without AECOPD. Higher WBC count, neutrophil count, and NLR were associated with the 3-year occurrence of AECOPD in the univariate analysis, but only the higher neutrophil count was a significant risk factor (odds ratio [OR] = 1.468; 95% confidence interval [CI]: 1.024-2.104) in the covariates-adjusted analysis. In the analysis of changes in inflammatory parameters, a decrease in the platelet count (OR = 0.502; 95% CI: 0.280-0.902) and NLR (OR = 0.535; 95% CI: 0.294-0.974) at 2 years and an increase in the eosinophil count (OR = 2.130; 95% CI: 1.027-4.416) at 3 years were significantly associated with AECOPD in the adjusted analysis. Conclusion: Our data suggest that a high baseline WBC count, particularly neutrophil count, was associated with a higher incidence of long-term AECOPD.

Impact of preserved ratio impaired spirometry on coronary artery calcium score progression: a longitudinal cohort study.

Background: Preserved ratio impaired spirometry (PRISm) is associated with increased cardiovascular disease (CVD) risk and mortality. However, a causal relationship between PRISm and CVD remains unclear. We investigated the progression of coronary artery calcium (CAC) scores based on the presence of PRISm and reduced forced vital capacity (FVC). Methods: This retrospective cohort study included 11 420 participants aged ≥40 years with forced expiratory volume in 1 s (FEV1)/FVC ≥0.7 who underwent at least two health screening examinations with coronary computed tomography scan between 2003 and 2020, and were without a history of CVD or interstitial lung disease. Participants with PRISm, defined as FEV1/FVC ≥0.7 and FEV1 <80% predicted, were further divided by low FVC (FVC <80% predicted). We estimated the 5-year progression rates of CAC by comparing participants with and without PRISm at baseline using mixed linear models. Results: Of the 11 420 participants, 8536 (75%), 811 (7%) and 2073 (18%) had normal spirometry, PRISm with normal FVC and PRISm with low FVC, respectively. During the mean (range) follow-up of 6.0 (0.5-17.2) years, the multivariable adjusted ratio of 5-year CAC progression rates comparing participants with PRISm to those with normal spirometry was 1.08 (95% CI 1.04-1.13). This rate was higher in participants with PRISm with low FVC (1.21 (95% CI 1.12-1.30)) than in those with normal FVC. Conclusion: In this longitudinal cohort study of subjects without a history of CVD, PRISm was significantly associated with CAC progression, which was more evident in the group with PRISm and low FVC.

Association Between Regular Moderate to Vigorous Physical Activity Initiation Following COPD Diagnosis and Mortality: An Emulated Target Trial Using Nationwide Cohort Data.

BACKGROUND: Moderate to vigorous physical activity (MVPA) in patients with COPD affects their overall health outcomes, including symptom relief and improved quality of life. However, the magnitude of the effect of MVPA initiation on real-world clinical outcomes has not been well investigated. RESEARCH QUESTION: How does MVPA initiation affect mortality and severe exacerbation in patients who have not engaged in MVPA prior to COPD diagnosis? STUDY DESIGN AND METHODS: This study included patients with COPD aged ≥ 40 years who were not performing MVPA prior to COPD diagnosis and who had at least one health screening visit prior to and following their COPD diagnosis between January 1, 2010, and December 31, 2018. The main exposure was MVPA, defined as vigorous aerobic exercise > 20 min per day on ≥ 3 days per week or moderate aerobic exercise > 30 min per day on ≥ 5 days per week. The primary end point was all-cause mortality, and the secondary end point was initial severe exacerbation as the time to event following COPD diagnosis. RESULTS: In total, 110,097 person-trials were included (27,564 MVPA increases and 82,533 control groups). No differences were observed between the covariates following matching. The adjusted hazards ratio of all-cause mortality for the MVPA group compared with the control group was 0.84 (95% CI, 0.79-0.89). In the subgroup analysis, patients aged > 65 years, female patients, those who had never smoked, and patients with a higher Charlson Comorbidity Index score displayed a stronger effect of MVPA on reducing mortality than younger male patients, those who had ever smoked, and patients with a lower Charlson Comorbidity Index score (Pinteraction < .05). The fully adjusted hazards ratio for the risk of severe exacerbation (MVPA group vs control) was 0.90 (95% CI, 0.87-0.94). INTERPRETATION: Initiation of MVPA can potentially reduce mortality and severe exacerbations in patients with COPD, although personalized interventions and further clinical trials are necessary.

Factors associated with failure of cardiopulmonary function recovery after lung cancer surgery.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the longitudinal changes in cardiopulmonary function (CPF) and identify predictors of cardiopulmonary recovery failure after lung cancer surgery. METHODS: Data was obtained from a prospective CATCH-LUNG cohort study, where patients were divided into two groups based on 6-min walk distance (6MWD) at baseline and 6 months after surgery. CPF recovery failure was defined as a participant whose 6MWD dropped over 50 m from baseline to 6 months after surgery. Patients with a baseline 6MWD less than 400 m were excluded. The analysis was investigated using mixed effects models, and the relative estimates for the predictors were expressed relative risk (RR) and 95% CI using a Poisson regression. RESULTS: Among 419 patients, 24.1% and 17.7% showed failure of CPF recovery at 6 months and 1 year after surgery, respectively. In the multivariable analysis, baseline step count [RR per 1000 steps lower = 1.05 (95% CI, 1.01-1.09)], baseline dyspnoea [RR per 10 points higher = 1.15(1.07-1.23)], decreased FEV1 % predicted from baseline to 2 weeks after surgery [RR per 10% lower = 1.30(1.10-1.53)] and decreased moderate-to-vigorous physical activity (MVPA) from baseline to 2 weeks [RR = 1.95(1.22, 3.11)] or persistent low MVPA at baseline and 2 weeks after surgery [RR = 1.63(1.04, 2.54)] were significant factors for loss of CPF. CONCLUSION: The inability to recover CPF at 6 months after surgery was linked to reduction of lung function and MVPA from baseline to 2 weeks as well as baseline physical activity (PA) and dyspnoea. These results imply that engagement of perioperative PA is necessary to facilitate recovery of CPF after lung cancer surgery.

Air pollution and mortality in patients with chronic obstructive pulmonary disease: a cohort study in South Korea.

Background: Evidence on whether long-term exposure to air pollution increases the mortality risk in patients with chronic obstructive pulmonary disease (COPD) is limited. Objectives: We aimed to investigate the associations of long-term exposure to particulate matter with diameter <10 µm (PM10) and nitrogen dioxide (NO2) with overall and disease-specific mortality in COPD patients. Design: We conducted a nationwide retrospective cohort study of 121,423 adults ⩾40 years diagnosed with COPD during 1 January to 31 December 2009. Methods: Exposure to PM10 and NO2 was estimated for residential location using the ordinary kriging method. We estimated the risk of overall mortality associated with 1-, 3-, and 5-years average concentrations of PM10 and NO2 using Cox proportional hazards models and disease-specific mortality using the Fine and Gray method adjusted for age, sex, income, body mass index, smoking, comorbidities, and exacerbation history. Results: The adjusted hazard ratios (HRs) for overall mortality associated with a 10 µg/m3 increase in 1-year PM10 and NO2 exposures were 1.004 [95% confidence interval (CI) = 0.985, 1.023] and 0.993 (95% CI = 0.984, 1.002), respectively. The results were similar for 3- and 5-year exposures. For a 10-µg/m3 increase in 1-year PM10 and NO2 exposures, the adjusted HRs for chronic lower airway disease mortality were 1.068 (95% CI = 1.024, 1.113) and 1.029 (95% CI = 1.009, 1.050), respectively. In stratified analyses, exposures to PM10 and NO2 were associated with overall mortality in patients who were underweight and had a history of severe exacerbation. Conclusion: In this large population-based study of patients with COPD, long-term PM10 and NO2 exposures were not associated with overall mortality but were associated with chronic lower airway disease mortality. PM10 and NO2 exposures were both associated with an increased risk of overall mortality, and with overall mortality in underweight individuals and those with a history of severe exacerbation.

Definitions of Chronic Obstructive Pulmonary Disease and Chronic Obstructive Pulmonary Disease Exacerbation: A Modified Delphi Survey.

BACKGROUND: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) update 2023 proposed new definitions of chronic obstructive pulmonary disease (COPD) and COPD exacerbation. However, an agreement on the definitions has not been made, either internationally or domestically. This study aimed to reach an agreement between experts on the new definitions of COPD and COPD exacerbation in South Korea. METHODS: A modified Delphi method was used to make an agreement on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023. We performed two rounds of the survey including 15 Korean experts on COPD, asthma, and tuberculosis. RESULTS: More than two-thirds of the experts agreed on 12 of the 13 statements related to the definitions of COPD and COPD exacerbation in the two rounds of the survey. The experts agreed on the definitions of COPD and COPD exacerbation that should be revised in line with the definitions proposed by the GOLD update 2023. However, the experts showed an uncertain opinion on the statement that the definition of COPD includes patients with persistent airflow obstruction due to bronchiectasis. CONCLUSION: Based on this Delphi survey, experts' agreement was made on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023.