Coupling mechanism of cerebral oxygenation reserve and microstructural damage in heart failure patients and its impact on cognitive function: a multimodal MRI study

Background Heart failure (HF) is often associated with cognitive impairment, yet the underlying mechanisms of brain structural and functional alterations remain unclear. Objective To evaluate changes in cerebral oxygen reserve and microstructural integrity in HF patients using multimodal magnetic resonance imaging (MRI) and to explore their relationship with cognitive dysfunction. Methods A total of 45 HF patients and 31 healthy controls (HC) were enrolled. Based on cognitive assessments, HF patients were further divided into two subgroups: those with and without cognitive impairment. All participants underwent 3D-T1, resting-state BOLD, and DTI scans to obtain parameters including cerebral oxygen reserve index (CORE), gray matter volume (GMV), diffusion tensor image analysis along the perivascular space index (ALPS), choroid plexus volume (CP volume), perivascular space score (PVS score), and fractional anisotropy (FA). Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) within 24 hours after MRI scanning. Intergroup comparisons and correlation analyses were performed using SPSS software. Results Compared to the HC group, HF patients exhibited significantly lower global CORE, GMV, mean ALPS index, and MoCA scores (all P < 0.05), while CP volume, PVS score, and free water fraction (FW) were significantly increased (all P < 0.05). Notably, more pronounced reductions in cerebral oxygen signals were observed in specific subregions including the right inferior frontal gyrus, left superior frontal gyrus, and left precentral gyrus in HF patients. These regional decreases were accompanied by reduced ALPS index and GMV in the corresponding areas. Correlation analyses revealed that MoCA scores were positively correlated with global CORE (r = 0.815) and mean ALPS index (r = 0.486) (both P < 0.05). Conclusion Heart failure patients demonstrate widespread brain structural and functional impairments, with reduced cerebral oxygen reserve in key frontal and precentral regions closely associated with glymphatic system dysfunction. These multimodal MRI alterations may serve as important neuroimaging markers for HF-related cognitive impairment. Combined assessment of regional cerebral oxygen signals and the ALPS index could help elucidate the underlying mechanisms of cognitive decline in heart failure patients.