Cardiovascular risk stratification using chest CT in idiopathic inflammatory myopathies

OBJECTIVE: To evaluate the diagnostic and prognostic value of incidentally detected coronary artery calcification (CAC) on routine chest computed tomography (CT) for cardiovascular risk stratification in patients with idiopathic inflammatory myopathies (IIM). METHODS: In this single-centre cross-sectional study, adult patients with IIM who underwent noncardiac, nongated high-resolution chest CT (HRCT) were included. CAC was visually categorized as absent, mild, moderate, or severe. Diagnostic performance for established coronary artery disease (CAD) and established cardiovascular (CV) events was assessed. Kaplan-Meier analyses evaluated CV death-free survival, and multivariable logistic regression identified factors associated with CAC. A matched systemic sclerosis (SSc) cohort served as validation cohort. RESULTS: Among 234 patients with IIM (mean age 57.1±15.9 years; 70.1% female), CAC was present in 43.2%. Higher CAC thresholds showed greater specificity for established CAD and prior CV events, whereas lower thresholds were more sensitive. CAC was associated with reduced CV death-free survival (log-rank p = 0.0095), with a stepwise decline across CAC severity categories. Findings were similar in the matched SSc cohort. Increasing CAC burden was associated with older age, smoking, higher CV risk burden, interstitial lung disease, and higher disease activity. In adjusted analyses, high disease activity was independently associated with moderate CAC (OR 4.01, 95% CI 1.29-12.50), while a higher number of concomitant DMARDs was associated with severe CAC (OR 2.55, 95% CI 1.27-5.11). CONCLUSION: Incidentally detected CAC on routine chest CT provides diagnostic and prognostic information in IIM and may represent a pragmatic approach to improve cardiovascular risk stratification in this high-risk population.