Diffusing capacity as an independent predictor of acute exacerbations in chronic obstructive pulmonary disease

A tale as old as time - the importance of accelerated lung aging in chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is progressive in nature and predominantly affects older individuals. Lung function decline is a typical part of the aging process, characterized by gradual loss of lung mechanics, airway remodeling, persistent low-grade inflammation of the airways, compromised epithelial barrier function, and impaired immune responses over time.

AREAS COVERED

The pathology of the senile lung is advanced in patients with COPD, whereby genomic damages contribute to structural defects and cellular dysfunction. Primary, antagonistic, and integrative hallmarks of aging are accelerated in COPD, potentiated by cumulative injury sustained from repeated environmental exposures and the interaction with comorbidities. Identification of epigenetic profiles in COPD indicates how cellular processes contribute to the advancement of biological age. Epigenetic abnormalities unique to COPD subpopulations occur in individuals who are immunodeficient, and often experience early onset and increased severity of COPD.

EXPERT OPINION

Accelerated aging processes indicated by epigenetic and other biomarkers may be a promising avenue for early detection, prevention, and subsequent management of COPD. Understanding risk factors contributing to progressive lung function decline and implementation of mitigation strategies such as cessation of smoking, repurposing existing pharmacotherapeutics and development of novel therapies may slow age-related pathologies in COPD. [Figure: see text].

Longitudinal recovery trajectories and ventilatory modalities in COVID-19 acute respiratory distress syndrome survivors

Background

The impact of different ventilatory support modalities and timing of intubation on longitudinal lung recovery trajectories in patients with severe coronavirus disease 2019 (COVID-19) is unknown.

Methods

This was a multicentre, prospective observational study conducted in 52 Spanish intensive care units (ICUs) involving critically ill COVID-19 patients admitted between 25 February 2020 and 8 February 2021. 1854 COVID-19 patients were followed after hospital discharge at 3, 6 and 12 months with diffusing capacity of the lung for carbon monoxide (D LCO) measurements and chest imaging. Patients were classified regarding the ventilatory support received during the ICU stay: noninvasive mechanical ventilation (NIMV), high-flow nasal cannula (HFNC) and invasive mechanical ventilation (IMV), divided into early IMV (intubation within 24 h) and late IMV (intubation after 24 h). The primary objective was to evaluate the impact of the different respiratory support modalities during the ICU stay and the time of intubation on D LCO measurements and their recovery trajectories over a 1-year follow-up. Secondary outcomes included other pulmonary function parameters and chest imaging findings.

Results

A total of 360 (19.4%) and 290 (15.6%) patients received HFNC and NIMV, respectively. 1204 (64.9%) patients underwent IMV; 966 received early IMV and 238 received late IMV. The latter exhibited a significantly worse percentage predicted D LCO during the 1-year follow-up with adjusted differences of 6.9 (95% CI 3.9-10; p<0.001), 4.2 (95% CI 1.1-7.2; p=0.007) and 4.9 (95% CI 1.7-8.2; p=0.003) at 3, 6 and 12 months compared with early IMV. NIMV patients exhibited greater lung damage at follow-up than those under HFNC with an adjusted difference of percentage predicted D LCO of 5.2 (95% CI 1.7-8.7; p=0.003) at 6 months and greater presence of radiological abnormalities during follow-up. Matched and sensitivity analysis showed results consistent with those reported.

Conclusions

Delay in intubation implies the worst outcomes; however, patients with NIMV exhibited a slower lung recovery in terms of D LCO measurements and more radiological abnormalities compared with HFNC patients. These results should be used to optimise follow-up protocols for COVID-19 acute respiratory distress syndrome (ARDS) survivors.

Risk factors of acute exacerbation and disease progression in young patients with COPD

OBJECTIVE

We aimed to elucidate the clinical factors associated with acute exacerbation and disease progression in young patients with chronic obstructive pulmonary disease (COPD).

METHODS

This retrospective longitudinal observational study included patients with COPD aged between 20 and 50 years with post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC)<0.7. Eligible patients were followed up with ≥2 spirometry examinations at 1 year interval after COPD diagnosis. The primary outcome was moderate-to-severe acute exacerbation in young patients with COPD. Secondary outcomes were early initiation of regular inhalation therapy and accelerated annual post-bronchodilator FEV1 decline.

RESULTS

A total of 342 patients were followed up during a median of 64 months. In multivariable analyses, risk factors for moderate-to-severe exacerbation were history of asthma (adjusted HR (aHR)=2.999, 95% CI=[2.074-4.335]), emphysema (aHR=1.951, 95% CI=[1.331-2.960]), blood eosinophil count >300/µL (aHR=1.469, 95% CI=[1.038-2.081]) and low FEV1 (%) (aHR=0.979, 95% CI=[0.970-0.987]). A history of asthma, sputum, blood eosinophil count >300/µL, low FEV1 (%) and low diffusing capacity of the lung for carbon monoxide (DLCO) (%) were identified as clinical factors associated with the early initiation of regular inhalation therapy. The risk factors associated with worsened FEV1 decline were increasing age, female sex, history of pulmonary tuberculosis, sputum, low FEV1 (%) and low DLCO (%).

CONCLUSIONS

In young COPD patients, specific high-risk features of acute exacerbation and disease progression need to be identified, including a history of previous respiratory diseases, current respiratory symptoms, blood eosinophil counts, and structural or functional pulmonary impairment.

Differential decline of lung function in COPD patients according to structural abnormality in chest CT

BACKGROUND

Different progressions or prognoses of chronic obstructive pulmonary disease (COPD) have been reported according to structural abnormalities based on chest computed tomography (CT). This study aimed to investigate whether different structural abnormalities independently affect annual lung function changes and clinical prognosis in patients with COPD.

METHODS

This longitudinal multicenter observational study was conducted using the KOCOSS cohort (NCT02800499) database in Korea from January 2012 to December 2019. For COPD patients with chest CT findings at baseline enrolment and longitudinal spirometric data, annual forced expiratory volume in 1 s (FEV1) decline rate (mL/year) and clinical outcomes were compared according to structural abnormalities, including emphysema, bronchiectasis (BE), and tuberculosis-destroyed lung (TDL). We estimated the adjusted annual FEV1 changes using a mixed-effect linear regression model.

RESULTS

Among the enrolled 237 patients, 152 showed structural abnormalities. Emphysema, BE, and TDL were observed in 119 (78.3%), 28 (18.4%), and 27 (17.8%) patients, respectively. The annual decline in FEV1 was faster in COPD patients with structural abnormalities than those without (β = -70.6 mL/year, P-value = 0.039). BE/TDL-dominant or emphysema-dominant structural abnormality contributed to an accelerated annual FEV1 decline compared to no structural abnormality (BE/TDL-dominant, β = -103.7 mL/year, P-value = 0.043; emphysema-dominant, β = -84.1 mL/year, P-value = 0.018). Structural abnormalities made no significant differences in acute exacerbation rate and mortality.

CONCLUSION

The lung function decline rate in COPD differed according to structural abnormalities on CT. These findings may suggest that more focus should be placed on earlier intervention or regular follow-up with spirometry in COPD patients with BE or TDL on chest CT.