Mannino, David M.

Abstract Background Nontuberculous mycobacterial pulmonary disease (NTMPD) is a chronic lung infection that is challenging to treat, especially refractory NTMPD. Data are limited on the natural history, risk profile, and burden of refractory NTMPD. The objective of this study was to evaluate the burden of illness (BOI) among patients with NTMPD who later develop refractory NTMPD vs those who do not. Methods This was a retrospective analysis using BRR data. Patients treated for NTMPD were included and stratified as refractory (received oral clofazimine/bedaquiline or inhaled amikacin/ALIS, or remained sputum culture positive despite ≥ 6 months of treatment) or nonrefractory. Modified bronchiectasis severity index (mBSI) at baseline visit and BOI including comorbid conditions and surgeries at the treatment visit were compared by cross-sectional analysis between the two groups. Longitudinal analysis of BOI focused on exacerbations and hospitalizations in the refractory group at their pre-refractory visit and refractory visit (first visit meeting the refractory definition). Results A total of 1,064 patients treated for NTMPD were included: 462 (43.4%) refractory and 602 (56.6%) nonrefractory. During the baseline period, the refractory group had more severe bronchiectasis (Table 1, mBSI, mean [SD], 7.3 [3.4] vs 6.7 [3.4]). At the time of treatment, bronchiectasis was more common in the refractory than nonrefractory (96.2% vs 89.7%) group, as were hemoptysis (26.6% vs 16.3%) and GERD (50.5% vs 39.9%). Except BMI, there were no statistically significant differences between the pre-refractory and nonrefractory treatment visits (Table 2). In the refractory group, exacerbations and hospitalizations remained high from the pre-refractory to refractory visit (45.6% vs 39.4% and 13.3% vs 12.8%, respectively). Oxygen and bronchial hygiene use increased from the pre-refractory to the refractory visit (5.2% vs 9.3% and 54.5% vs 61.7%, respectively) consistent with increased management of respiratory conditions when not responding to treatment (Table 2). Conclusion Refractory NTMPD imposes a high disease burden on patients in the BRR. This high burden was present at pre-refractory visits and through the development of refractory status. Disclosures Timothy R. Aksamit, MD, AstraZeneca: Advisor/Consultant|Baxter International, Hill-Rom: Advisor/Consultant|Insmed Incorporated: Advisor/Consultant|Johnson & Johnson: Advisor/Consultant|Redhill Biopharma: Advisor/Consultant|RespirTech: Advisor/Consultant|Spero Therapeutics: Advisor/Consultant|Zambon: Advisor/Consultant David M. Mannino, MD, AstraZeneca: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|Up to Date: Advisor/Consultant Ping Wang, PhD, Insmed Incorporated: Salary|Insmed Incorporated: Stocks/Bonds Mariam Hassan, PhD, B. Pharm, Insmed Incorporated: Salary|Insmed Incorporated: Stocks/Bonds

Abstract Rationale Staphylococcus aureus is commonly cultured from the sputum of patients with bronchiectasis; however, little is known about the prevalence of the organism in these patients, the characteristics of patients who have grown the organism, or its implications. Objectives Determine the relationship between S. aureus and pulmonary function, frequency of exacerbations, and frequency of hospitalization in patients with bronchiectasis Methods The Bronchiectasis Research Registry is a database of adults with non–cystic fibrosis bronchiectasis identified from 13 sites within the United States. Baseline and follow-up demographic, spirometric, microbiologic, and therapeutic data were entered into a central web-based database. Patients were grouped into three cohorts based on their previous respiratory cultures at the time of entry into the Registry: 1) no prior S. aureus or glucose-nonfermenting gram-negative bacilli (NF-GNB) (Pseudomonas, Stenotrophomonas, or Burkholderia spp.); 2) prior S. aureus at least once; or 3) no prior S. aureus but prior NF-GNB at least once. The association between S. aureus isolation and pulmonary function and frequency of exacerbations and hospital admissions was assessed, both at baseline and after 1 year of follow-up. Results S. aureus was cultured from 94 of 830 patients (11.3%) included in the analysis. Patients who had grown S. aureus before entry into the Registry had a frequency of prior exacerbations and baseline pulmonary function that was between that of patients who had grown NF-GNB and those who had grown neither NF-GNB or S. aureus. Similarly, at the first follow-up visit after study entry, patients who had grown S. aureus had a frequency of exacerbations and hospitalizations that was between those of patients who had grown NF-GNB and those who had grown neither NF-GNB nor S. aureus. However, in multivariate analysis, S. aureus was not associated with pulmonary function, frequency of exacerbation, or hospital admissions. There were no significant differences in patient characteristics or outcomes between patients who had methicillin-sensitive and methicillin-resistant S. aureus. Conclusions Staphylococcus aureus does not appear to be an independent risk factor for severe disease in patients with bronchiectasis enrolled in the Bronchiectasis Research Registry.