The Impact of High Ratio of Airway Luminal Volume to Blood Volume in the Lungs on Exacerbations in Chronic Obstructive Pulmonary Disease

Wakazono et al. investigated the impact of a high airway luminal volume-to-blood volume (TAV/TBV) ratio on exacerbation risk in COPD patients. Using baseline CT scans from 96 patients in the Hokkaido COPD Cohort and 130 in the Kyoto University cohort, they calculated TAV/TBV ratios with AVIEW software. Patients were divided into high and low TAV/TBV groups based on the third quartile. Kaplan-Meier and multivariable Cox models, adjusted for clinical factors, revealed that a high TAV/TBV ratio was associated with a shorter time to first exacerbation. In multivariable models, a high TAV/TBV ratio significantly increased exacerbation risk (HR: 4.79 in Hokkaido; HR: 1.72 in Kyoto), independent of the PA/Ao ratio. These findings suggest that TAV/TBV could serve as a non-invasive CT biomarker for exacerbation risk in COPD, offering potential for improved patient risk stratification. Further validation in larger and more diverse cohorts is recommended.