Progression of bronchiectasis on CT and mortality in smokers

<bold>Background:</bold> Whether bronchiectasis progression on CT portends an adverse prognosis in smokers is poorly understood. We tested the hypothesis that the progression of bronchiectasis on CT is associated with higher mortality in smokers with normal and impaired spirometry. <bold>Methods:</bold> We quantified the percentage of airways with airway-to-artery diameter ratio (AAR) >1, a defining feature of radiologic bronchiectasis, using a validated artificial intelligence-based tool on CT scans from the COPDGene Study. Changes in the percentage of airways with AAR>1 from baseline to year 5 in smokers with normal spirometry, preserved ratio and impaired spirometry (PRISm), and COPD were classified as stable, ≤0%; slow progression, 1%-4%; and rapid progression, ≥5%. The association between bronchiectasis changes and all-cause mortality was assessed with multivariable Cox models. <bold>Results:</bold> During a median follow-up of 12 years, mortality rates were 9%, 15%, and 27% in the normal spirometry (n= 2019), PRISm (n= 549), and COPD (n= 1714) groups, respectively. In adjusted models, compared to stable bronchiectasis on CT, rapid progression but not slow progression was associated with a significantly higher risk of all-cause mortality in all spirometric groups, with the greatest risk in the normal spirometry and PRISm groups (Figure). <fig><object-id>erj;64/suppl_68/PA651/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusion:</bold> Bronchiectasis progression on CT is associated with an elevated risk of mortality in smokers with normal and impaired spirometry.