Abstract
BACKGROUND: Recent PET studies suggest a link between amygdala activity and cardiovascular disease. Altered amygdala volumes are associated with increased stressor-evoked cardiovascular reactivity, which potentially increases the risk for cardiovascular disease. Therefore, we investigated the association between amygdala volume and MRI-based markers of cardiovascular disease in order to evaluate morphological alterations of the amygdala in persons with early, clinically inapparent signs of cardiovascular complications. MATERIALS AND METHODS: 400 subjects underwent a comprehensive 3-T MRI to estimate amygdala volume and imaging-based markers of cardiovascular disease, specifically carotid plaque presence and grading, media wall thickening, left ventricular myocardial mass, myocardial late gadolinium enhancement, and left ventricular function. Amygdala volume was automatically segmented based on FLAIR images and corrected for total intracranial volume. Logistic and linear regression analyses of amygdala volume and cardiovascular parameters were conducted while controlling for age, gender and cardiovascular risk factors. RESULTS: Among 339 included subjects (mean age: 56.3 ± 9.1, 57% males), the average absolute amygdala volume was 3.04 ± 0.24 mL, and the average amygdala ratio was 0.213 ± 0.017% of total intracranial volume. Carotid plaque was present in 22.6%, and myocardial late gadolinium enhancement in 3.2%. Mean media wall thickening was 0.76 ± 0.1 mm, mean left ventricular myocardial mass 71.6 ± 14.1 g/m(2), and mean ejection fraction 69.1 ± 8.2%. Logistic and linear regression analyses showed no significant association of amygdala volume and any of the MRI-based cardiovascular parameters (p > 0.05, respectively). CONCLUSIONS: Amygdala volume was not associated with early MRI-based markers of cardiovascular disease, suggesting that the amygdala is not morphologically altered in the initial phase of cardiovascular disease. CRITICAL RELEVANCE STATEMENT: This first large MRI study demonstrates that amygdala volume is not associated with subclinical cardiovascular disease, critically refining prior PET-based hypotheses and advancing clinical radiology by clarifying the preserved role of amygdala morphology in early cardiovascular pathology. KEY POINTS: PET studies link amygdala activity to cardiovascular disease, while the role of amygdala volume in early cardiovascular disease is unclear. In this large population-based study, 339 asymptomatic adults who underwent comprehensive 3-T MRI with cardiovascular assessment were analyzed. Amygdala volume showed no association with MRI markers of subclinical cardiovascular disease. This is the first large MRI study linking amygdala volume and early cardiovascular disease.