Brain-heart interactions are associated with mortality and acute encephalopathy in ICU patients with severe COVID-19

Research in critical care has revealed the significance of autonomic dysfunctions, and more recently of brain-heart interactions, as valuable biomarkers for evaluating patients' physiological status. These biomarkers provide insights into consciousness levels, severity, and outcomes. This study aims to determine the potential of these biomarkers in predicting the mortality and neurological outcome of severe COVID-19 patients.

We examined severe COVID-19 patients who required mechanical ventilation and observed them both during sedation and after sedation cessation. Standard EEG and ECG recordings were conducted at bedside, from which 5 min of continuous data were analyzed. Using a synthetic data generation model, we evaluated bidirectional brain-heart interactions from EEG power and heartbeat dynamics series.

Our findings indicate that brain-heart interactions, especially involving cardiac parasympathetic activity, indicate the degree of patients' severity. We observed correlations with acute encephalopathy duration (coma and delirium), particularly evident in top-down markers (from brain to heart) while bottom-up signaling (from heart to brain) correlated with ICU mortality. Additionally, we noted stronger modulation of brain-heart interactions in milder patients when comparing sedation versus non-sedation conditions, compared to those in more severe states.

Our results imply that autonomic dysfunctions, as measured through brain-heart interactions, can track the pathophysiology of comatose states following SARS-CoV-2 infection.

These findings highlight the potential of brain-heart interactions as an integrated marker for autonomic function in critical care, offering a more accurate assessment of patient severity and outcomes compared to isolated cardiac or brain measures.