Preoperative regional homogeneity predicts postoperative delirium susceptibility after cardiac surgery

Area of Science:

• Neuroimaging
• Cardiac Surgery
• Geriatric Medicine

Background:

• Postoperative delirium (POD) is a frequent complication following cardiac surgery, associated with increased morbidity and prolonged hospital stays.
• Objective preoperative neuroimaging markers for predicting POD are currently lacking, hindering effective risk stratification and intervention.
• Understanding the interplay between cardiac function and brain activity is crucial for elucidating POD mechanisms.

Purpose of the Study:

• To investigate whether preoperative regional homogeneity (ReHo) alterations detected via resting-state functional MRI correlate with POD development.
• To assess the predictive value of preoperative ReHo for POD in patients undergoing valve replacement surgery.
• To explore the relationship between ReHo, cardiac function, and cognitive performance in the context of POD.

Main Methods:

• Prospective observational study involving patients undergoing valve replacement surgery.
• Preoperative resting-state functional MRI data acquisition to measure regional homogeneity (ReHo).
• Postoperative delirium assessment using standardized tools; Support Vector Machine (SVM) models for predictive analysis incorporating ReHo and age.

Main Results:

• Patients who developed POD showed significantly reduced preoperative ReHo in the left hippocampus, precuneus, and rolandic operculum compared to non-POD patients.
• Lower hippocampal ReHo correlated with poorer cardiac function, and altered rolandic operculum ReHo was linked to episodic memory deficits.
• Machine learning models combining preoperative ReHo features and age demonstrated discriminative ability for predicting POD.

Conclusions:

• Preoperative ReHo alterations in key brain regions indicate an underlying neural susceptibility to POD.
• Integrating ReHo metrics with patient age may enhance preoperative risk stratification for POD after cardiac surgery.
• These findings highlight the significant heart-brain interactions contributing to POD risk.