Suspected bronchiectasis linked to high mortality risk regardless of lung function
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Key takeaways:
- Adults with a long-term smoking history suspected to have bronchiectasis faced an elevated mortality risk regardless of lung function.
- Imaging and clinical criteria should be used when suspecting this disease.
Fulfilling criteria for suspected bronchiectasis raised the risk for all-cause mortality among adults with a smoking history, even if they had normal lung function, according to results published in Annals of Internal Medicine.
“If a patient who smokes has features of bronchiectasis on a chest CT ordered by unrelated reasons and report[s] respiratory symptoms, it warrants a further workup for bronchiectasis,” Alejandro A. Diaz, MD, MPH, assistant professor of medicine at Harvard Medical School and associate scientist at Brigham and Women’s Hospital, told Healio. “Patients with COPD and bronchiectasis on CT (incidental or not) also require additional workup to rule out other causes of the airway abnormality and adjusting clinical management (eg, antibiotic regime duration for flare-up episodes).”
In a prospective, observational cohort study, Diaz and colleagues assessed 7,662 adults (mean age, 60 years; 52% women) aged 45 to 80 years with a smoking history of at least 10 pack-years from the COPDGene study to find out if suspected bronchiectasis on CT scans is related to 10-year mortality among smokers with normal spirometry (n = 3,277), preserved ratio impaired spirometry (PRISm; n = 986) and obstructive spirometry, indicating COPD (n = 3,399).
Notably, adults from the COPDGene study are either non-Hispanic Black or white.
Researchers defined suspected bronchiectasis as an artificial intelligence-based measurement of airway-to-artery ratio (ARR) of more than one of 1% on CT scans and the presence of two of the following symptoms: cough, phlegm, dyspnea, and/or history of at least two exacerbations. Overall, 1,352 (17.6%) adults met both these criteria, whereas 2,893 (37.7%) had none of the criteria and served as the no suspected bronchiectasis reference group.
More than a quarter of adults (27.3%; n = 2,095) from the total cohort died within the median follow-up period of 11 years.
Compared with adults without suspected bronchiectasis, those with suspected bronchiectasis plus normal spirometry had an elevated 10-year mortality risk (difference in mortality probability, 0.15; 95% CI, 0.09-0.21) in models adjusted for several covariates including age, sex, race, BMI, current smoking status and more.
“It was surprising that suspected bronchiectasis (ie, incidental abnormal bronchial dilation on CT plus symptoms) indicated a higher mortality risk in people who smoke but have normal lung function,” Diaz told Healio.
Researchers also observed differences in 10-year mortality probability among those with suspected bronchiectasis in the PRISm group (0.07; 95% CI, –0.003 to 0.15) and in the obstructive spirometry group (0.06; 95% CI, 0.03-0.09) vs. those without suspected bronchiectasis.
When dividing adults from the obstructive group with suspected bronchiectasis according to their Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage, those with GOLD stage 1 to 2 (mild to moderate COPD) had a 10-year mortality probability of 0.29 (95% CI, 0.26-0.32), which was similar to the mortality probability observed in the GOLD stage 3 to 4 group, signaling severe to very severe COPD (0.28; 95% CI, 0.25-0.31).
When researchers analyzed the group of patients who only met the CT criteria for suspected bronchiectasis, they found that those with normal spirometry (n = 731) showed a lower difference in 10-year mortality probability (0.04; 95% CI, –0.001 to 0.08) compared with the no suspected bronchiectasis group.
“Of note, bronchiectasis findings on CT per se do not seem to increase mortality risk,” Diaz told Healio.
Lastly, as quartiles of AAR greater than one increased, adults in the normal and obstructive spirometry groups had higher all-cause mortality. Mortality was heightened from quartiles one to two in adults in the PRISm group and then stayed similar from quartile two to quartile four.
“Artificial intelligence-based imaging metrics as the one used in this study will be used more often in bronchiectasis studies, including trials and longitudinal studies,” Diaz told Healio.