Quantitative Imaging Markers on HRCT Predict Rapid Progression and Adverse Events of Patients with Idiopathic Inflammatory Myopathies-Related Interstitial Lung Disease.

To assess imaging quantitative markers on baseline High-resolution computed tomography (HRCT) for predicting rapid progression (RP) and adverse events in anti-synthetase syndrome associated interstitial lung disease (ASS-ILD) and anti-MDA5-positive dermatomyositis-associated interstitial lung disease (MDA5-ILD). This retrospective study analyzed 511 patients (ASS-ILD: n=356, median age=56 years; MDA5-ILD: n=155, median age=50 years) between Jan 2016 and Dec 2021. RP was defined as pulmonary function, image, or symptom aggravation within 3 months of initial presentation. Adverse events (death/intensive care) were recorded. Deep learning quantified ground-glass opacity (GGO) and consolidation volumes/percentages on baseline HRCT. Multivariable logistic and Cox regression adjusted for confounders (age, gender, smoking status, body mass index, fibrosis, and treatment). No multiple comparisons were conducted since this is an explorable study. RP occurred in 34.8% (124/356) of ASS-ILD and 44.5% (69/155) of MDA5-ILD patients. Elevated GGO/consolidation volumes and percentages independently predicted RP in patients with ASS-ILD (adjusted odd ratio=1.63, 95% confidence interval:1.25-2.12, P<0.001), but not in patients with MDA5-ILD. During median follow-up (ASS-ILD: 4.45 years; MDA5-ILD: 4.05 years), RP patients showed higher mortality versus patients without RP (hazard ratio=4.12, P<0.001). Increased baseline GGO/consolidation metrics predicted adverse events in patients with ASS-ILD or MDA5-ILD (P<0.01). GGO and consolidation quantification on baseline HRCT can provide clinically actionable predictors to identify patients with ASS-ILD at high-risk for RP, and to stratify adverse event risks across ASS/MDA5-ILD regardless of RP status, enabling early intervention.