Coronary artery disease (CAD) and cognitive impairment (CI) represent a significant public health challenge, with the heart-brain axis theory explaining their interrelationship. CAD damages the microstructure of brain white matter, disrupts the functional connectivity of brain networks, and causes gray matter atrophy through chronic cerebral hypoperfusion, small vessel disease, neuroinflammation, and oxidative stress, leading to cognitive decline. Multimodal magnetic resonance imaging (MRI) of the brain is used to assess damage to the heart-brain axis. Graph-theoretic analysis and artificial intelligence enable the identification of relationships between abnormal brain network topology, cardiovascular risk phenotypes and imaging functions in CAD patients and serve as promising biomarkers. The review systematically examines MRI biomarkers as objective tools to validate the traditional Chinese medicine (TCM) heart-brain theory in CAD-related CI. It clarifies the convergence of holistic TCM concepts with modern neuroimaging and provides a framework for imaging evaluation to guide the development of integrated TCM and Western medicine strategies for synergistic treatment of the heart and brain.