A Prospective Study on Autonomic Functions in Idiopathic Inflammatory Myopathies: The AFIIM Study.

Area of Science:

• Cardiology
• Neurology
• Rheumatology

Background:

• Dysautonomia is an underrecognized manifestation in idiopathic inflammatory myopathies (IIM).
• Autonomic dysfunction can impact disease prognosis and clinical management in IIM.
• Cardiac involvement is a significant concern in IIM patients.

Purpose of the Study:

• To assess autonomic dysfunction in IIM patients.
• To investigate the correlation between autonomic dysfunction and cardiac imaging biomarkers using cardiac magnetic resonance imaging (CMRI).
• To explore the potential of autonomic function testing (AFT) as a predictor of cardiac involvement in IIM.

Main Methods:

• Recruited IIM patients (aged 10-60) and age/sex-matched healthy controls.
• Conducted autonomic function testing (AFT), tilt table test (TTT), and CMRI with multiparametric mapping.
• Assessed myositis disease activity using the myositis disease activity assessment tool (MDAAT).

Main Results:

• IIM patients exhibited significantly lower total autonomic power and mean standard deviation of normal-to-normal intervals (SDNN) compared to controls.
• Autonomic function testing (AFT) parameters, including SDNN and total autonomic power, showed a negative correlation with native-T1-mapping on CMRI.
• Specific cut-offs for SDNN and total autonomic power demonstrated high sensitivity and specificity in predicting cardiac involvement.

Conclusions:

• This study is the first to integrate AFT and TTT with CMRI in evaluating IIM.
• Patients with IIM demonstrate significant autonomic dysfunction.
• AFT parameters correlate with CMRI findings, suggesting their utility as simple predictors of cardiac involvement in IIM.