Interactions between the heart and the brain in heart failure patients assessed by magnetic resonance imaging - interim results from Brain assessment and investigation in Heart Failure Trial (B-HeFT)

Abstract

Purpose: Heart failure (HF) affects almost all organs in our body through reduced organ perfusion and resultant neurohumoral alterations. Major depression is more prevalent in HF patients as compared with normal subjects, suggesting the possible interactions between the heart and the brain in HF. However, functional and structural brain changes in HF patients remain largely unclear. We thus prospectively performed Brain Assessment and Investigation in Heart Failure Trial (B-HeFT) (UMI08584), in which we investigated the interactions between the two vital organs by magnetic resonance (MR) imaging in Stage B/C HF patients. Methods: Stage B (n=14) and Stage C (n=16) HF patients, who were diagnosed by echocardiography and past HF symptoms, underwent brain and cardiac MR image acquisitions and questionnaires including the Minnesota Living with Heart Failure Questionnaire (Stage C, 38.5±6.5 vs. Stage B, 21.6±4.9, P<0.05) and the Beck depression inventory (Stage C, 11.9±2.3 vs. Stage B, 8.7±1.7, P=0.27). The brain MR images were analyzed to detect regional alterations in grey matter between Stage B and C groups as measured by grey matter probability values (a maximum value of 1). Left ventricular ejection fraction (LVEF), cardiac index (CI) and LV end-diastolic volume (LVEDV) were obtained from the cardiac MR images using Simpson's method. Results: Stage C and B groups did not differ in age (Stage C, 65.4±1.7 vs. Stage B, 63.3±3.7 years) or ischemic origin (Stage C, 50.0 vs. Stage B, 57.1%). Analysis of the cardiac MR images demonstrated significant cardiac remodeling in Stage C than in Stage B group, including reduced LVEF (Stage C, 34.2±4.3 vs. Stage B, 55.0±34.2%, P<0.01), increased LVEDV (Stage C, 194±25 vs. Stage B, 125±11 ml, P<0.05) and a tendency for reduced CI (Stage C, 2.2±0.2 vs. Stage B, 2.6±0.3 ml/m2/min, P=0.19). Analysis of the brain MR images identified grey matter reduction in Stage C as compared with Stage B group not only in regions associated with depressive symptoms such as the right hippocampus (Stage C, 0.559±0.016 vs. Stage B, 0.574±0.018, P<0.05) but also in the bilateral primary motor cortex (Stage C, 0.320±0.017 vs. Stage B, 0.337±0.016, P<0.05). There was a tendency for a positive correlation between increased LVEDV and grey matter reduction in the right hippocampus (Stage C, r=0.37, P=0.20; Stage B, r=0.28, P=0.34). Conclusion: These results indicate that HF is associated with cardiac remodeling along with grey matter reduction in the hippocampus and the primary motor cortex, which may be involved in depressive symptoms and reduced daily activity in HF patients.