Relation between resting amygdala activity and cardiovascular events in patients with cardiac sarcoidosis

Previous studies indicate amygdala activity (AmygA) measured by FDG-positron emission tomography (PET) predicts the risk of subsequent cardiovascular events. However, AmygA measurement use for predicting the prognosis of patients with cardiac sarcoidosis (CS) is unknown. We aimed to investigate the association between AmygA and cardiovascular events in patients with CS.

Consecutive 40 patients with CS who underwent FDG-PET were identified retrospectively. Cardiovascular events included ventricular tachyarrhythmias and heart failure hospitalizations. We examined the association between AmygA and cardiovascular events and investigated the timing of FDG-PET influence on AmygA measurements.

During a follow-up of 4.5 (2.5-7.7) years, 14 (35%) patients experienced cardiovascular events. Left-AmygA was a stronger cardiovascular event predictor than the Right-AmygA, and incidences were significantly higher in the high left-AmygA group than low group (log-rank P = 0.018). Multivariable analysis revealed left-AmygA augmentation (hazard ratio [HR]: 1.76 per 0.1 increase, 95% confidence interval [CI]: 1.12-2.87, P = 0.016) was the only independent predictor of cardiovascular event. Among the 40 patients, 32 underwent multiple PET-scans. No significant difference was found between the AmygA value on the first PET-scan and the mean on multiple PET scans, and the correlation coefficient was 0.93 (P < 0.001). Multivariate analyses revealed the mean left-AmygA value was the only independent predictor of cardiovascular event (P = 0.011).

High left-AmygA was associated with the higher rates of cardiovascular events in patients with CS. AmygA would be a prognostic biomarker regardless of the PET-scan timing.