Retrospective study of the predictors of mortality and radiographic deterioration in 782 patients with nodular/bronchiectatic Mycobacterium avium complex lung disease

Abstract

Objectives: Some patients with nodular/bronchiectatic Mycobacterium avium complex lung disease (NB MAC-LD) deteriorate and die. The main aim of the study is to evaluate the prognostic factors and radiographic outcomes in patients with NB MAC-LD.

Setting: Retrospective single-centre review.

Participants: 782 HIV-negative patients with NB MAC-LD treated at our institution in Japan.

Primary and secondary outcome measures: All-cause and MAC-LD progression mortality rates and the prognostic factors, and radiographic deterioration rates and the prognostic factors.

Results: Mean age was 68.1 years, and median follow-up period was 4.3 years. Death from any cause and progression of MAC lung disease (MAC-LD) occurred in 130 (16.6%), and 19 (2.4%) patients, respectively. All-cause and MAC-LD progression 10-year mortality rates were 27.4% and 4.8%, respectively. In 536 patients with MAC-LD who were followed-up for more than 1 year, radiographic deterioration occurred in 221 (41.2%) patients and median time-to-radiographic deterioration was 9 years. A multivariate Cox proportional hazard model showed male sex, older age, body mass index <18.5 kg/m(2), absence of bloody sputum, hypoalbuminaemia and erythrocyte sedimentation rate >40 mm/h to be negative prognostic factors for all-cause mortality, and the presence of idiopathic pulmonary fibrosis, haemoglobin <11.3 mg/dL, C reactive protein >1.0 mg/dL and the presence of cavity to be negative prognostic factors for radiographic deterioration.

Conclusions: Only 2.4% of patients with NB MAC-LD died from MAC-LD progression. As clinical trials testing the effectiveness of drug therapy in patients with NB MAC-LD are being designed and implemented, the primary end point could be time-to-radiographic deterioration, and trial patients need to be stratified according to these prognostic factors before randomisation.

Figure 1

Kaplan-Meier survival curves of all-cause mortality of patients with nodular/bronchiectatic Mycobacterium avium complex lung disease with or without bloody sputum. Overall cumulative 5-year and 10-year mortality rates were 12.5% and 27.4%, respectively. Five-year and 10-year all-cause mortality rate in the patients without bloody sputum were 14% and 29%, versus 5.9% and 19.9% in those with bloody sputum (p=0.018), respectively.

Figure 2

Kaplan-Meier survival curves of Mycobacterium avium complex lung disease (MAC-LD) progression mortality of patients with nodular/bronchiectatic MAC-LD with or without cavity. Five-year and 10-year MAC-LD progression mortality rates were 2% and 4.8%, respectively. Five-year and 10-year MAC-LD progression mortality rates in the patients with cavity were 8.5% and 25.1%, versus 0.8% for each period in those without cavity, respectively (p<0.001).

Figure 3

Kaplan-Meier curves of the probability of no radiographic deterioration of patients with nodular/bronchiectatic Mycobacterium avium complex lung disease with or without cavity. Cumulative median time-to-radiographic deterioration was 9 years, and 5-year and 10-year radiographic deterioration rates were 39.1% and 54%, respectively. Median time-to-radiographic deterioration and 5-year and 10-year radiographic deterioration rate in the patients with cavity were 30 years, and 66.7% and 70.4%, versus 10 years, and 34.6% and 51.7%, in those without cavity, respectively (p<0.001).