Cardiac Magnetic Resonance Imaging Markers in Idiopathic Inflammatory Myopathy - A Prospective Observational Study

Idiopathic inflammatory myopathies (IIMs) encompass a spectrum of conditions with diverse muscular and extra-muscular symptoms, including cardiac manifestations, which significantly impact morbidity and mortality. Our study aims to assess cardiac involvement markers in IIM using cardiac magnetic resonance imaging (CMR) and evaluate their association with disease severity.

We recruited 62 participants prospectively, including 31 clinically suspected IIM patients and 31 healthy controls who were matched by age and sex. CMR with multiparametric mapping (1.5 T magnetic resonance imaging) and the Myositis Disease Activity Assessment Tool (MDAAT) were used in the evaluation.

With a mean age of 35.3 ± 12.2 years and a female preponderance (F:M = 2.4:1), the majority of the study population (77.4%) exhibited positive myositis-specific antibodies, whereas 45.2% had myositis-associated antibodies. Cardiac symptoms were reported by 45.2% of the cases, while 48.3% had an MDAAT cardiac Visual Analog Scale (VAS) score of ≥1, indicating potential cardiac involvement. Cases had significantly higher native T1 and T2 mapping values (1085.7 ± 57.7 vs. 1043.3 ± 36.1 ms, P = 0.002 and 52.9 ± 4.3 vs. 50.4 ± 2.6 ms, P = 0.011, respectively). Late gadolinium enhancement was seen in 6.4%. The native T1 value positively correlated with the MDAAT total score (ρ = 0.376, P < 0.014) and cardiac VAS score (ρ = 0.259, P = 0.038). A native T1 value ≥1048.25 ms has 72.7% sensitivity and 51.4% specificity (AUC = 0.711, P = 0.019) in detecting cardiac involvement.

Clinical parameters and CMR multiparametric mapping are shown to be correlated in this prospective investigation. It is the first study to look at the cardiac mapping parameters' sensitivity and specificity to MDAAT-based cardiac involvement. In the Indian population with IIM, it is the first assessment of cardiac involvement utilizing CMR. In IIM, this endeavor is expected to greatly improve early detection, prevention, and treatment of cardiac complications.