Suspected Bronchiectasis and Mortality in Adults With a History of Smoking Who Have Normal and Impaired Lung Function
Alejandro A. Díaz, Wei Wang, J. Orejas, Rim Elalami, W.R. Dolliver, Pietro Nardelli, R. San José Estépar, Bina Choi, Carrie L. Pistenmaa, James C. Ross, Diego J. Maselli, Andrew Yen, Kendra A. Young, Gregory L. Kinney, Michael H. Cho, Raúl San Jośe Estépar
Abstract
BACKGROUND: Bronchiectasis in adults with chronic obstructive pulmonary disease (COPD) is associated with greater mortality. However, whether suspected bronchiectasis-defined as incidental bronchiectasis on computed tomography (CT) images plus clinical manifestation-is associated with increased mortality in adults with a history of smoking with normal spirometry and preserved ratio impaired spirometry (PRISm) is unknown. OBJECTIVE: To determine the association between suspected bronchiectasis and mortality in adults with normal spirometry, PRISm, and obstructive spirometry. DESIGN: Prospective, observational cohort. SETTING: The COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) study. PARTICIPANTS: = 3399). MEASUREMENTS: Bronchiectasis identified by CT was ascertained using artificial intelligence-based measurements of an airway-to-artery ratio (AAR) greater than 1 (AAR >1), a measure of bronchial dilatation. The primary outcome of "suspected bronchiectasis" was defined as an AAR >1 of greater than 1% plus 2 of the following: cough, phlegm, dyspnea, and history of 2 or more exacerbations. RESULTS: Among the 7662 participants (mean age, 60 years; 52% women), 1352 (17.6%) had suspected bronchiectasis. During a median follow-up of 11 years, 2095 (27.3%) died. Ten-year mortality risk was higher in participants with suspected bronchiectasis, compared with those without suspected bronchiectasis (normal spirometry: difference in mortality probability [Pr], 0.15 [95% CI, 0.09 to 0.21]; PRISm: Pr, 0.07 [CI, -0.003 to 0.15]; obstructive spirometry: Pr, 0.06 [CI, 0.03 to 0.09]). When only CT was used to identify bronchiectasis, the differences were attenuated in the normal spirometry (Pr, 0.04 [CI, -0.001 to 0.08]). LIMITATIONS: Only 2 racial groups were studied. Only 1 measurement was used to define bronchiectasis on CT. Symptoms of suspected bronchiectasis were nonspecific. CONCLUSION: Suspected bronchiectasis was associated with a heightened risk for mortality in adults with normal and obstructive spirometry. PRIMARY FUNDING SOURCE: National Heart, Lung, and Blood Institute.