Setting: Kyoto, Japan.
Objective: To determine predictors of 5-year mortality in pulmonary Mycobacterium avium-intracellulare complex (MAC) disease.
Design: Retrospective study of 164 patients diagnosed with pulmonary MAC disease between 1999 and 2005 and followed for 5 years.
Results: Overall 5-year mortality was 28.0%. Among 117 patients with microbiological outcomes, 54 were treated (treated MAC patients) and 24 were not treated and did not experience sputum culture conversion during follow-up (untreated chronic MAC patients); 39 patients were not treated and experienced sputum culture conversion. Five-year all-cause overall mortality among the 78 patients with definite MAC disease (including treated and untreated chronic MAC patients) was 25.6%. The mortality rate was 33.3% for untreated chronic MAC patients only vs. 22.2% for treated MAC patients (P = 0.30). After adjustment for clinical, microbiological and radiological confounders, independent factors for 5-year mortality were a high Charlson comorbidity index in cases with definite MAC disease (hazard ratio [HR] 1.76) and untreated chronic MAC (HR 3.08), and presence of cavitary lesions in cases with definite MAC disease (HR 1.82) and treated MAC patients (HR 3.91).
Conclusion: Patients with cavitary lesions require immediate treatment for sputum culture conversion and to improve their chances of survival.