Association of lung field area with mortality in Mycobacterium avium complex lung disease: a longitudinal cohort study.

BACKGROUND

Nontuberculous mycobacteria (NTM), particularly the Mycobacterium avium complex (MAC), is becoming a global health burden with increasing incidence worldwide. Previous studies have linked pulmonary function impairment with increased mortality in NTM lung disease, suggesting that lung volume may be a critical predictor of mortality. The objective of this study was to assess the prognostic value of lung field area (LFA) in predicting all-cause mortality among patients with MAC lung disease.

METHODS

We conducted a longitudinal cohort study of 232 patients diagnosed with MAC lung disease at NHO Fukuoka National Hospital from April 1996 to December 2021. Quantitative CT image analysis was performed to measure LFA. Statistical analysis included Kaplan-Meier curves and Cox proportional hazards models to estimate mortality risk, adjusting for demographic and clinical variables.

RESULTS

Patients with lower LFAs had significantly higher mortality rates (P < 0.01 for a trend), with a multivariable-adjusted hazard ratio of 5.90 (95% CI, 1.85-18.76) for the lowest tertile as compared to the highest. The predicting ability of mean LFA for all-cause death was superior to that of cavitary lesions assessed by low-attenuation areas (LAA), with area under the curve values of 0.77 for LFA versus 0.53 for LAA (P < 0.01).

CONCLUSION

Decreased LFA is an independent risk factor for mortality in patients with MAC lung disease, offering better prognostic utility than traditional markers of disease severity such as cavity lesions. These findings highlight the potential for LFA to guide clinical management and risk stratification in MAC lung disease.