scholarly journals Association of lung clearance index with survival in individuals with cystic fibrosis

2021 ◽  
Author(s):  
Johanna M Kurz ◽  
Kathryn A Ramsey ◽  
Romy Rodriguez ◽  
Ben Spycher ◽  
Reta Fischer Biner ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Sensitivity Analyses ◽  
Event Analysis ◽  
Z Score ◽  
Lung Clearance ◽  
Risk Of Death ◽  
Ventilation Inhomogeneity ◽  
Hazard Ratios ◽  
Lung Clearance Index ◽  
The Mean

Background: Lung clearance index (LCI) quantifies global ventilation inhomogeneity, a sensitive biomarker of airway function in cystic fibrosis (CF) lung disease. Objectives: We examined the association of LCI with the risk of death or lung transplantation (LTX) in individuals with CF. Methods: We performed a retrospective analysis in a cohort of individuals with CF aged ≥ five years with available LCI and FEV1 measurements between 1980 and 2006. Outcome was time until death or LTX. We applied Cox proportional hazard regressions using the earliest available LCI and FEV1 values and adjusted for demographic and clinical variables. For sensitivity analyses, we used the mean of the first three LCI and FEV1 measurements, stratified the cohort based on age, and investigated individuals with normal FEV1. Results: In total, 237 individuals with CF aged mean (range) 13.9 (5.6-41.0) years were included. This time-to-event analysis accrued 3813 person-years, 94 (40%) individuals died or received LTX. Crude hazard ratios [95% CI] were 1.04 [1.01-1.06] per one z-score increase in LCI and 1.25 [1.11-1.41] per one z-score decrease in FEV1. After adjusting LCI and FEV1 mutually in addition to sex, age, BMI and the number of hospitalisations, hazard ratios were 1.04 [1.01-1.07] for LCI, and 1.12 [0.95-1.33] for FEV1. Sensitivity analyses yielded similar results and using the mean LCI strengthened the associations. Conclusions: Increased ventilation inhomogeneity is associated with greater risk of death or LTX. Our data support LCI as novel surrogate of survival in individuals with CF.

scholarly journals Association of lung clearance index with survival in individuals with cystic fibrosis

2021 ◽  
pp. 2100432
Author(s):  
Johanna Manuela Kurz ◽  
Kathryn Angela Ramsey ◽  
Romy Rodriguez ◽  
Ben Spycher ◽  
Reta Fischer Biner ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Sensitivity Analyses ◽  
Event Analysis ◽  
Z Score ◽  
Lung Clearance ◽  
Risk Of Death ◽  
Ventilation Inhomogeneity ◽  
Hazard Ratios ◽  
Lung Clearance Index ◽  
The Mean

BackgroundThe lung clearance index (LCI) assesses global ventilation inhomogeneity and is a sensitive biomarker of airway function in cystic fibrosis (CF) lung disease.ObjectivesWe examined the association of LCI with the risk of death or lung transplantation (LTX) in individuals with CF.MethodsWe performed a retrospective analysis in a cohort of individuals with CF aged≥5 years with LCI and FEV1 measurements performed between 1980 and 2006. The outcome was time until death or LTX. We used the earliest available LCI and FEV1 values in a Cox proportional hazard regression adjusted for demographic and clinical variables. For sensitivity analyses, we used the mean of the first three LCI and FEV1 measurements, stratified the cohort based on age, and investigated individuals with normal FEV1.ResultsIn total, 237 individuals with CF with a mean (range) age of 13.9 (5.6–41.0) years were included. The time-to-event analysis accrued 3813 person-years and 94 (40%) individuals died or received LTX. Crude hazard ratios [95% CI] were 1.04 [1.01–1.06] per one z-score increase in LCI and 1.25 [1.11–1.41] per one z-score decrease in FEV1. After adjusting LCI and FEV1 mutually in addition to sex, age, BMI and the number of hospitalisations, hazard ratios were 1.04 [1.01–1.07] for LCI, and 1.12 [0.95–1.33] for FEV1. Sensitivity analyses yielded similar results and using the mean LCI strengthened the associations.ConclusionsIncreased ventilation inhomogeneity is associated with greater risk of death or LTX. Our data support LCI as novel surrogate of survival in individuals with CF.

scholarly journals Elevated lung clearance index in infants with cystic fibrosis shortly after birth

2017 ◽  
Vol 50 (5) ◽  
pp. 1700580 ◽  
Author(s):  
Elisabeth Kieninger ◽  
Sophie Yammine ◽  
Insa Korten ◽  
Pinelopi Anagnostopoulou ◽  
Florian Singer ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Specific Treatment ◽  
Lung Clearance ◽  
Time To Peak ◽  
Ventilation Inhomogeneity ◽  
Lung Clearance Index ◽  
Residual Capacity ◽  
Z Scores ◽  
Noninvasive Markers

It is not known at what age lung function impairment may arise in children with cystic fibrosis (CF). We assessed lung function shortly after birth in infants with CF diagnosed by newborn screening.We performed infant lung function measurements in a prospective cohort of infants with CF and healthy controls. We assessed lung clearance index (LCI), functional residual capacity (FRC) and tidal breathing parameters. The primary outcome was prevalence and severity of abnormal lung function (±1.64 z-scores) in CF.We enrolled 53 infants with CF (mean age 7.8 weeks) and 57 controls (mean age 5.2 weeks). Compared to controls, LCI and FRC were elevated (mean difference 0.30, 95% CI 0.02–0.60; p=0.034 and 14.5 mL, 95% CI 7.7–21.3 mL; p<0.001, respectively), while ratio of time to peak tidal expiratory flow to expiratory time was decreased in infants with CF. In 22 (41.5%) infants with CF, either LCI or FRC exceeded 1.64 z-scores; three infants had both elevated LCI and FRC.Shortly after birth, abnormal lung function is prevalent in CF infants. Ventilation inhomogeneity or hyperinflation may serve as noninvasive markers to monitor CF lung disease and specific treatment effects, and could thus be used as outcome parameters for future intervention studies in this age group.

scholarly journals Longitudinal assessment of lung clearance index to monitor disease progression in children and adults with cystic fibrosis

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2021-216928
Author(s):  
Alex R Horsley ◽  
John Belcher ◽  
Katie Bayfield ◽  
Brooke Bianco ◽  
Steve Cunningham ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Clinical Practice ◽  
Lung Function ◽  
Latent Class ◽  
Longitudinal Change ◽  
Test Time ◽  
Longitudinal Assessment ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
The Mean

BackgroundLung clearance index (LCI) is a valuable research tool in cystic fibrosis (CF) but clinical application has been limited by technical challenges and uncertainty about how to interpret longitudinal change. In order to help inform clinical practice, this study aimed to assess feasibility, repeatability and longitudinal LCI change in children and adults with CF with predominantly mild baseline disease.MethodsProspective, 3-year, multicentre, observational study of repeated LCI measurement at time of clinical review in patients with CF >5 years, delivered using a rapid wash-in system.Results112 patients completed at least one LCI assessment and 98 (90%) were still under follow-up at study end. The median (IQR) age was 14.7 (8.6–22.2) years and the mean (SD) FEV1 z-score was −1.2 (1.3). Of 81 subjects with normal FEV1 (>−2 z-scores), 63% had raised LCI (indicating worse lung function). For repeat stable measurements within 6 months, the mean (limits of agreement) change in LCI was 0.9% (−18.8% to 20.7%). A latent class growth model analysis identified four discrete clusters with high accuracy, differentiated by baseline LCI and FEV1. Baseline LCI was the strongest factor associated with longitudinal change. The median total test time was under 19 min.ConclusionsMost patients with CF with well-preserved lung function show stable LCI over time. Cluster behaviours can be identified and baseline LCI is a risk factor for future progression. These results support the use of LCI in clinical practice in identifying patients at risk of lung function decline.

scholarly journals Patterns of regional lung physiology in cystic fibrosis using ventilation magnetic resonance imaging and multiple-breath washout

2018 ◽  
Vol 52 (5) ◽  
pp. 1800821 ◽  
Author(s):  
Laurie J. Smith ◽  
Guilhem J. Collier ◽  
Helen Marshall ◽  
Paul J.C. Hughes ◽  
Alberto M. Biancardi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cystic Fibrosis ◽  
Total Lung Capacity ◽  
Resonance Imaging ◽  
Ventilation Distribution ◽  
Lung Clearance ◽  
Lung Capacity ◽  
Lung Clearance Index ◽  
Ventilation Heterogeneity ◽  
Multiple Breath Washout

Hyperpolarised helium-3 (3He) ventilation magnetic resonance imaging (MRI) and multiple-breath washout (MBW) are sensitive methods for detecting lung disease in cystic fibrosis (CF). We aimed to explore their relationship across a broad range of CF disease severity and patient age, as well as assess the effect of inhaled lung volume on ventilation distribution.32 children and adults with CF underwent MBW and 3He-MRI at a lung volume of end-inspiratory tidal volume (EIVT). In addition, 28 patients performed 3He-MRI at total lung capacity. 3He-MRI scans were quantitatively analysed for ventilation defect percentage (VDP), ventilation heterogeneity index (VHI) and the number and size of individual contiguous ventilation defects. From MBW, the lung clearance index, convection-dependent ventilation heterogeneity (Scond) and convection–diffusion-dependent ventilation heterogeneity (Sacin) were calculated.VDP and VHI at EIVT strongly correlated with lung clearance index (r=0.89 and r=0.88, respectively), Sacin (r=0.84 and r=0.82, respectively) and forced expiratory volume in 1 s (FEV1) (r=−0.79 and r=−0.78, respectively). Two distinct 3He-MRI patterns were highlighted: patients with abnormal FEV1 had significantly (p<0.001) larger, but fewer, contiguous defects than those with normal FEV1, who tended to have numerous small volume defects. These two MRI patterns were delineated by a VDP of ∼10%. At total lung capacity, when compared to EIVT, VDP and VHI reduced in all subjects (p<0.001), demonstrating improved ventilation distribution and regions of volume-reversible and nonreversible ventilation abnormalities.

Six‐minute walk, lung clearance index, and QOL in bronchiolitis obliterans and cystic fibrosis

2018 ◽  
Vol 54 (4) ◽  
pp. 451-456 ◽  
Author(s):  
Michal Gur ◽  
Kamal Masarweh ◽  
Yazeed Toukan ◽  
Vered Nir ◽  
Ronen Bar‐Yoseph ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Bronchiolitis Obliterans ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
Minute Walk

Natural Variability of Clinically Measured Lung Clearance Index in Children with Cystic Fibrosis

2021 ◽  
Author(s):  
Bettina Sarah Frauchiger ◽  
Kathryn Ramsey ◽  
Jakob Usemann ◽  
Elisabeth Kieninger ◽  
Carmen Casaulta ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Natural Variability ◽  
Lung Clearance ◽  
Lung Clearance Index
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