Heart Rate Variability Response to Therapist‐Selected Music as a Diagnostic Biomarker for Disorders of Consciousness

Music, as an auditory stimulus, has long been recognized for its ability to evoke heart rate variability (HRV) responses. In patients with disorders of consciousness (DOC), these responses may provide valuable insights into consciousness levels. However, the diagnostic value of music‐induced HRV and the influence of music type remain unclear. This study evaluated HRV under baseline (BL), patient‐preferred music (PPM), and therapist‐selected music (TSM) conditions in 15 minimally conscious state (MCS) and 14 vegetative state (VS) patients. Six HRV metrics showed significant differences between MCS and VS groups exclusively during TSM. Principal component analysis reduced these metrics into two components (PC1 was predominantly weighted by HF kurtosis, reflecting vagal modulation, whereas PC2 was associated with LHr, indicating sympathovagal balance), explaining > 99.45% of variance. A linear regression model using PC1 and PC2 under TSM significantly predicted Coma Recovery Scale‐Revised (CRS‐R) scores (adjusted R 2 = 0.328, p = 0.003), outperforming PPM and BL models. This study establishes TSM‐induced HRV as an effective diagnostic biomarker for DOC and links the HRV‐based autonomic responses to the CRS‐R‐based behavioral assessment of consciousness. Clinical Trial Registration: This study was registered as NCT05382260 at ClinicalTrials.gov on March 18, 2022.