International Variation in Severe Exacerbation Rates in Patients With Severe Asthma

BACKGROUND

Exacerbation frequency strongly influences treatment choices in patients with severe asthma.

RESEARCH QUESTION

What is the extent of the variability of exacerbations rate across countries and its implications in disease management?

STUDY DESIGN AND METHODS

We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients ≥ 18 years of age who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naïve model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables.

RESULTS

The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39).

INTERPRETATION

Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.

Clinical Predictors of Severe Exacerbations in Pediatric Patients With Recurrent Wheezing

Introduction Wheezing is common in preschool-aged children, affecting about half of all children within their first six years of life. Children who have recurrent wheezing experience disease-related morbidity, including increased emergency visits and hospitalizations. Early-life lower respiratory tract viral infections are linked to recurrent wheezing and eventual asthma onset. Identifying high-risk children is crucial, with the frequency and severity of wheezing episodes being good predictors of long-term outcomes. Aim To identify predictors of severe exacerbations in children with recurrent wheezing. Methods We conducted a retrospective cohort study involving 168 pediatric patients with recurrent wheezing followed up at our outpatient clinic. The outcome of interest was the occurrence of a severe exacerbation, defined as any exacerbation requiring hospitalization and the need for supplemental oxygenation or ventilatory support. Results The median age of the first wheezing exacerbation was five months, with a predominance of the male gender. Approximately two-thirds of the patients had a family history of atopy. Comorbid allergic rhinitis and atopic dermatitis were present in 15.4% and 16.7% of patients, respectively. Twenty percent of patients had a severe wheezing exacerbation as the first form of presentation, and 30% presented at least one severe exacerbation from the first presentation to the last follow-up. Patients with severe exacerbations were younger at the first episode (median age 4 months, IQR 2-7, versus 7 months, IQR 4-12, p=0.027) and more frequently had a family history of atopy (71.7% versus 55.6%, p=0.050). In this cohort, patients who initially presented with a severe episode are at increased risk of incident severe exacerbations during follow-up, HR 2.24 (95%CI 1.01-4.95). Conclusions We know that the severity of exacerbations in children with recurrent wheezing correlates with the long-term outcomes of the disease. Therefore, preventing severe exacerbations can positively impact the prognosis of these patients. In this analysis, we found independent predictors of severe exacerbations to be the first clinical episode before the age of three months and a family history of atopy. We also found that patients whose initial presentation was severe have a higher risk of new severe exacerbations. Therefore, these subgroups of patients should be closely monitored by pediatricians.

Lung Mycobiota α-Diversity Is Linked to Severity in Critically Ill Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) affects more than 200 million people worldwide. The chronic course of COPD is frequently worsened by acute exacerbations (AECOPD). Mortality in patients hospitalized for severe AECOPD remains dramatically high, and the underlying mechanisms are poorly understood. Lung microbiota is associated with COPD outcomes in nonsevere AECOPD, but no study specifically investigated severe AECOPD patients. The aim of this study is thus to compare lung microbiota composition between severe AECOPD survivors and nonsurvivors. Induced sputum or endotracheal aspirate was collected at admission from every consecutive severe AECOPD patient. After DNA extraction, the V3-V4 and ITS2 regions were amplified by PCR. Deep-sequencing was performed on a MiSeq sequencer (Illumina); the data were analyzed using DADA2 pipeline. Among 47 patients admitted for severe AECOPD, 25 (53%) with samples of sufficient quality were included: 21 of 25 (84%) survivors and 4 of 25 (16%) nonsurvivors. AECOPD nonsurvivors had lower α-diversities indices than survivors for lung mycobiota but not for lung bacteriobiota. Similar results were demonstrated comparing patients receiving invasive mechanical ventilation (n = 13 [52%]) with those receiving only noninvasive ventilation (n = 12 [48%]). Previous systemic antimicrobial therapy and long-term inhaled corticosteroid therapy could alter the lung microbiota composition in severe AECOPD patients. In acidemic AECOPD, lower lung mycobiota α-diversity is linked to the severity of the exacerbation, assessed by mortality and the requirement for invasive mechanical ventilation, whereas lung bacteriobiota α-diversity is not. This study encourages a multicenter cohort study investigating the role of lung microbiota, especially fungal kingdom, in severe AECOPD. IMPORTANCE In AECOPD with acidemia, more severe patients-i.e., nonsurvivors and patients requiring invasive mechanical ventilation-have lower lung mycobiota α-diversity than survivors and patients receiving only noninvasive ventilation, respectively. This study encourages a large multicenter cohort study investigating the role of lung microbiota in severe AECOPD and urges investigation of the role of the fungal kingdom in severe AECOPD.

Influence of Comorbidities and Airway Clearance on Mortality and Outcomes of Patients With Severe Bronchiectasis Exacerbations in Taiwan

Bronchiectasis is characterized by systemic inflammation and multiple comorbidities. This study aimed to investigate the clinical outcomes based on the bronchiectasis etiology comorbidity index (BACI) score in patients hospitalized for severe bronchiectasis exacerbations. We included non-cystic fibrosis patients hospitalized for severe bronchiectasis exacerbations between January 2008 and December 2016 from the Chang Gung Research Database (CGRD) cohort. The main outcome was the 1-year mortality rate after severe exacerbations. We used the Cox regression model to assess the risk factors of 1-year mortality. Of 1,235 patients who were hospitalized for severe bronchiectasis exacerbations, 641 were in the BACI < 6 group and 594 in the BACI ≥ 6 group. The BACI ≥ 6 group had more previous exacerbations and a lower FEV₁. Pseudomonas aeruginosa (19.1%) was the most common bacterium, followed by Klebsiella pneumoniae (7.5%). Overall, 11.8% of patients had respiratory failure and the hospital mortality was 3.0%. After discharge, compared to the BACI < 6 group, the BACI ≥ 6 group had a significantly higher cumulative incidence of respiratory failure and mortality in a 1-year follow-up. The risk factors for 1-year mortality in a multivariate analysis include age [hazard ratio (HR) 4.38, p = 0.01], being male (HR 4.38, p = 0.01), and systemic corticosteroid usage (HR 6.35, p = 0.001), while airway clearance therapy (ACT) (HR 0.50, p = 0.010) was associated with a lower mortality risk. An increased risk of respiratory failure and mortality in a 1-year follow-up after severe exacerbations was observed in bronchiectasis patients with multimorbidities, particularly older age patients, male patients, and patients with a history of systemic corticosteroid use. ACT could effectively improve the risk for 1-year mortality.

Will the asthma revolution fostered by biologics also benefit adult ICU patients?

PURPOSE

Asthma exacerbations are inflammatory events that rarely result in full hospitalization following an ER visit. Unfortunately, certain patients require prolonged support, including occasional external lung support through ECMO or ECCOR (with subsequent further exposure to other life-threatening issues), and some die. In parallel, biologics are revolutionizing severe asthma management, mostly in T2 high patients.

METHODS

We extensively reviewed the current unmet needs surrounding ICU-admitted asthma exacerbations, with a focus on currently available drugs and the underlying biological processes involved. We explored whether currently available T2-targeting drugs can reasonably be seen as potential players not only for relapse prevention but also as candidate drugs for a faster resolution of such episodes. The patient's perspective was also sought.

RESULTS

About 30% of asthma exacerbations admitted to the ICU do not resolve within five days. Persistent severe airway obstruction despite massive doses of corticosteroids and maximal pharmacologically induced bronchodilation is the main cause of treatment failure. Previous ICU admission is the main risk factor for such episodes and may eventually be considered as a T2 surrogate marker. Fatal asthma cases are hallmarked by poorly steroid-sensitive T2-inflammation associated with severe mucus plugging. New, fast-acting T2-targeting biologics (already used for preventing asthma exacerbations) have the potential to circumvent steroid sensitivity pathways and decrease mucus plugging. This unmet need was confirmed by patients who reported highly negative, traumatizing experiences.

CONCLUSIONS

There is room for improvement in the management of ICU-admitted severe asthma episodes. Clinical trials assessing how biologics might improve ICU outcomes are direly needed.

Neutrophil-to-Lymphocyte Ratio Predicts Clinical Outcome of Severe Acute Exacerbation of COPD in Frequent Exacerbators

Purpose

Frequent exacerbators are a specific phenotype of chronic obstructive pulmonary disease (COPD), whose clinical characteristics and prognostic biomarkers during severe acute exacerbation (AECOPD) have not yet been fully elucidated. The aim of this study was to investigate the clinical features of severe AECOPD in frequent exacerbators and explore the predictive value of the neutrophil-to-lymphocyte ratio (NLR) for outcome in this phenotype during severe exacerbation.

Patients and Methods

A total of 604 patients with severe AECOPD were retrospectively included in the study. Subjects were defined as frequent exacerbators if they experienced two or more exacerbations in the past year. Clinical characteristics and worse outcome (ICU admission, or invasive ventilation, or in-hospital mortality) during severe AECOPD were compared between frequent exacerbators and non-frequent ones. Furthermore, the relationship between NLR and worse outcome in frequent exacerbators was analyzed using logistic regression and receiver operating characteristic (ROC).

Results

Among 604 patients with severe AECOPD, 282 (46.69%) were frequent exacerbators and 322 (53.31%) were non-frequent exacerbators. Compared with the non-frequent ones, frequent exacerbators presented higher levels of NLR (5.93 [IQR, 3.40–9.28] vs 4.41 [IQR, 2.74–6.80]; p<0.001), and more worse outcome incidence (58 [20.57%] vs 38 [11.80%]; p=0.003). Moreover, among the frequent exacerbators, NLR levels in the patients with worse outcome were much higher than in those without worse outcome (11.09 [IQR, 7.74–16.49] vs 5.28 [IQR, 2.93–7.93]; p<0.001). Increased NLR was significantly associated with a higher risk of worse outcome in frequent exacerbators (OR, 1.43; 95% CI, 1.28–1.64; p<0.001). Furthermore, ROC analysis revealed that a cut-off value of 10.23, NLR could predict worse outcome of severe AECOPD in frequent exacerbators (sensitivity 62.1%, specificity 92.0%, AUC 0.833).

Conclusion

Frequent exacerbators exhibited an increased level of NLR and a higher proportion of worse outcome during severe AECOPD. NLR is expected to be a promising predictive biomarker for the prognosis of severe AECOPD in frequent exacerbators.

Appearance of large scavenger receptor A-positive cells in peripheral blood: A potential risk factor for severe exacerbation of chronic obstructive pulmonary disease

Fresh peripheral blood (PB) samples from 432 outpatients with stable chronic obstructive pulmonary disease (COPD) were examined. Patients were classified into Group A (large SRA⁺ cells were undetected) and Group B (large SRA⁺ cells were detected) and followed‐up for 1 year. Patients were further subdivided according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. Cox proportional hazard model had shown that Gold, Group, home oxygen therapy (HOT), and treatment were significant predictors of severe exacerbation. Six of 353 patients in Group A and 29 of 79 in Group B developed severe exacerbation. The rates of severe exacerbation were significantly higher in Group B patients, GOLD stage 2 than Group A, GOLD stage 2; in Group B, GOLD stage 3 than Group A, GOLD stage 3; and in all of Group B compared with in all of Group A. The Kaplan‐Meier curves of Group B, GOLD stages 1–4, and of all of Group B showed significantly worse rates of severe exacerbation than those of Group A, Gold 1–4, and all of Group A, respectively. The appearance of large SRA⁺ cells in the PB of patients with stable COPD may represent a useful biomarker for severe COPD exacerbation.

Right heart failure as a risk factor for severe exacerbation in patients with chronic obstructive pulmonary disease: Prospective cohort study

BACKGROUND

The prognosis in patients with Chronic Obstructive Pulmonary Disease (COPD) depends, in large part, on the frequency of exacerbations. Cardiovascular diseases, including heart failure (HF), are the risk factors for exacerbations. However, the importance of HF type over the exacerbations in COPD patients is unknown.

OBJECTIVE

To determine whether right heart failure (RHF) is an independent risk factor for severe exacerbations in patients with COPD.

METHODS

A prospective cohort study of 133 patients diagnosed with COPD with a follow-up period from 2010 to 2016. Patients with bronchial hyperreactivity, asthma, or pulmonary embolism were excluded.

RESULTS

The mean age was 74.7 ± 8.2 years and 43.6% were men, 69.9% had severe exacerbations during follow-up. Subjects with RHF had lower FEV₁ (50.2 ± 19.9 vs 57.4 ± 16.9, P = .006) and greater incidence of stroke (15.4% vs 1.8%, P = .009) compared to those without RHF. Subjects with RHF were at higher risk of severe exacerbations (HR, 2.46; CI 95%, 1.32-4.58, P = .005) compared to those without RHF after adjusting for confounding variables.

CONCLUSION

In patients with COPD, RHF is an independent risk factor for suffering severe exacerbations.

Comparative effects of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on the risk of pneumonia and severe exacerbations in patients with COPD

Objectives

This study aimed to compare the effects of angiotensin-converting-enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) on the risk of pneumonia and severe exacerbations in patients with COPD.

Patients and methods

All patients with COPD who used ACEis and ARBs for >90 days between 2000 and 2005 were recruited. Pairwise matching (1:1) of the ACEi and ARB groups resulted in two similar subgroups, with 6,226 patients in each. The primary outcomes were pneumonia and COPD exacerbations, and the secondary outcome was death.

Results

During the follow-up period, the incidence of pneumonia was 7.20 per 100 person-years in the ACEi group and 5.89 per 100 person-years in the ARB group. The ACEi group had a higher risk of pneumonia (adjusted hazard ratio [aHR], 1.22; 95% CI, 1.15–1.29) than the ARB group. The incidence of severe exacerbations was 0.65 per person-year for the patients receiving ACEis and 0.52 per person-year for those receiving ARBs. The patients receiving ACEis had a higher risk of severe exacerbations (aHR, 1.19; 95% CI, 1.16–1.21) than those receiving ARBs. Similar trends were noted in terms of severe exacerbations requiring hospitalization (aHR, 1.24; 95% CI, 1.21–1.28) or emergency department visits (aHR, 1.16; 95% CI, 1.13–1.18), pneumonia requiring mechanical ventilation (aHR, 1.35; 95% CI, 1.24–1.47), and mortality (aHR, 1.33; 95% CI, 1.26–1.42).

Conclusion

ARBs were associated with lower rates of pneumonia, severe pneumonia, and mortality than ACEis in patients with COPD.

Estimating the effectiveness of pulmonary rehabilitation for COPD exacerbations: reduction of hospital inpatient days during the following year

AIMS

To study the short- and long-term results of pulmonary rehabilitation (PR) given in the Helsinki University Heart and Lung Center and to understand the hospital resources used to treat severe COPD exacerbations in the city of Helsinki.

MATERIALS AND METHODS

Seventy-eight inactive patients with severe COPD were recruited for a PR course; three of them did not finish the course. The course took 6-8 weeks and included 11-16 supervised exercise sessions. Using electronic medical records, we studied all COPD patients with hospital admission in the city of Helsinki in 2014, including COPD diagnosis, criteria for exacerbation, and potential exclusion/inclusion criteria for PR.

RESULTS

Seventy-five of the patients finished the PR course and 92% of those patients showed clinically significant improvement. Their hospital days were reduced by 54% when compared to the year before. At 1 year after the course, 53% of the patients reported that they have continued with regular exercise training. In the city of Helsinki, 437 COPD patients were treated in a hospital due to exacerbation during 2014. On the basis of their electronic medical records, 57% of them would be suitable for PR. According to a rough estimate, 10%-20% hospital days could be saved annually if PR was available to all, assuming that the PR results would be as good as those shown here.

CONCLUSIONS

The study showed that in a real-world setting, PR is efficient when measured by saved hospital days in severe COPD. Half of the patients could be motivated to continue exercising on their own.

Impact of exacerbations on health care cost and resource utilization in chronic obstructive pulmonary disease patients with chronic bronchitis from a predominantly Medicare population

BACKGROUND

Exacerbations of chronic obstructive pulmonary disease (COPD) lead to significant increases in resource utilization and cost to the health care system. COPD patients with chronic bronchitis and a history of exacerbations pose an additional burden to the system. This study examined health care utilization and cost among these patients.

METHODS

For this retrospective analysis, data were extracted from a large national health plan with a predominantly Medicare population. This study involved patients who were aged 40-89 years, had been enrolled continuously for 24 months or more, had at least two separate insurance claims for COPD with chronic bronchitis (International Classification of Diseases, Ninth Revision, Clinical Modification code 491.xx), and had pharmacy claims for COPD maintenance medications between January 1, 2007, and March 31, 2009. Two years of data were examined for each patient; the index date was defined as the first occurrence of COPD. Baseline characteristics were obtained from the first year of data, with health outcomes tracked in the second year. Severe exacerbation was defined by COPD-related hospitalization or death; moderate exacerbation was defined by oral or parenteral corticosteroid use. Adjusted numbers of exacerbations and COPD-related costs per patient were estimated controlling for demographic and clinical characteristics.

RESULTS

The final study sample involved 8554 patients; mean age was 70.1±8.6 years and 49.8% of the overall population had exacerbation, 13.9% had a severe exacerbation only, 29.1% had a moderate exacerbation only, and 6.8% had both a severe and moderate exacerbation. COPD-related mean annual costs were $4069 (all figures given in US dollars) for the overall population and $6381 for patients with two or more exacerbations. All-cause health care costs were $18,976 for the overall population and $23,901 for patients with history of two or more exacerbations. Severity of exacerbations, presence of cardiovascular disease, diabetes, and long-term oxygen use were associated with higher adjusted costs.

CONCLUSIONS

The results indicate that despite treatment with maintenance medications, COPD patients continue to have exacerbations resulting in higher costs. New medications and disease management interventions are warranted to reduce the severity and frequency of exacerbations and the related cost impact of the disease.