Journal Article

Acute exacerbation of rheumatoid arthritis-associated interstitial lung disease: mortality and its prediction model

Inui, Naoki, Nakamura, Yutaro, Suda, Takafumi, Furuhashi, Kazuki, Kono, Masato, Inoue, Yusuke, Enomoto, Noriyuki, Yokomura, Koshi, Suzuki, Yuzo, Hasegawa, Hirotsugu, Karayama, Masato, Fujisawa, Tomoyuki, Kato, Shinpei, Nakamura, Hidenori, Hozumi, Hironao

2022

Overview

Background Patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD), like those with idiopathic pulmonary fibrosis (IPF), might develop an unexpected acute exacerbation (AE)—a rapidly progressing and deadly respiratory decline. Although AE incidence and risk factors in RA-ILD patients are known, their post-AE clinical course remains unknown owing to the rarity of AE-RA-ILD. This multicentre retrospective study evaluated post-AE mortality and prognostic variables in AE-RA-ILD patients and created a mortality prediction model for AE-RA-ILD. Methods This research comprised 58 patients with AE-RA-ILD and 96 with AE-IPF (a control disease). Multivariate Cox regression analysis was performed to identify prognostic variables. A prediction model was created with recursive partitioning (decision tree). Results The post-AE 90-day mortality rate in the overall AE-RA-ILD group was 48.3%; percent predicted forced vital capacity within 12 months before AE onset (baseline %FVC) and PaO 2 /FiO 2 ratio at AE onset (P/F at AE) were independent predictors of mortality. Post-AE 90-day mortality rates were 40.6% and 43.8%, respectively, in AE-RA-ILD and AE-IPF patients propensity score-matched for age, sex, baseline %FVC and P/F at AE ( P  = 1.0000). In AE-RA-ILD patients, C -indices of baseline %FVC and P/F at AE to predict post-AE 90-day mortality were 0.604 and 0.623, respectively. A decision tree model based on these prognostic factors classified AE-RA-ILD patients into mild, moderate and severe groups (post-AE 90-day mortality rates: 20.8%, 64.0% and 88.9%, respectively; P  = 0.0002); the C -index improved to 0.775. Conclusions Post-AE mortality was high in AE-RA-ILD patients similar to AE-IPF patients. The discovered prognostic factors and our mortality prediction model may aid in the management of AE-RA-ILD patients.

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: Acute exacerbation / Aged / Aged, 80 and over / Arthritis, Rheumatoid - complications / Case-Control Studies / Complications and side effects / Decision Trees / Female / Humans / Interstitial lung disease / Lung diseases, Interstitial / Lung Diseases, Interstitial - etiology / Lung Diseases, Interstitial - mortality / Male / Medicine / Medicine & Public Health / Mortality / Mortality prediction model / Patient outcomes / Pneumology/Respiratory System / Prognosis / Prognostic factor / Retrospective Studies / Rheumatoid arthritis / Risk factors / Vital Capacity