The Metabolic Activity of the Spleen and Bone Marrow in Patients with Acute Myocardial Infarction Evaluated by 18F-FDG PET Imaging
Background—Atherosclerosis is considered to be an inflammatory disease associated with the activation of hematopoietic and immune-related organs such as the bone marrow (BM) and spleen. We evaluated the metabolic activity of those organs and of the carotid artery with 18F-FDG PET in patients with coronary artery disease, including acute myocardial infarction (AMI).
Methods and Results—Whole-body combined 18F-FDG PET/CT was performed in 32 patients with AMI, 33 patients with chronic stable angina, and 25 control subjects. The mean standard uptake value (SUV) was calculated in the regions of interest in the spleen and the BM of lumbar vertebrae. The target-to-background ratio (TBR) of the SUVs of the carotid artery and jugular vein was also calculated. In patients with AMI, the SUVs of the BM (1.67±0.16) and spleen (2.57±0.39), as well as the TBR of the carotid artery (2.13±0.42), were significantly higher than the corresponding values of patients with angina (1.22±0.62; 2.03±0.35; 1.36±0.37, all p<0.001) and controls (0.80±0.44; 1.54±0.26; 1.22±0.22, all p<0.001) independent of traditional cardiovascular risk factors and high-sensitivity CRP (hsCRP). In all groups combined, the TBR of the carotid artery was significantly associated with the SUVs of the BM (r=0.535, p<0.001), spleen (r=0.663, p<0.001), and hsCRP (r=0.465, p<0.001).
Conclusions—The metabolic activity of the BM and spleen as well as of the carotid artery was highest in patients with AMI, intermediate in patients with angina, and lowest in control subjects. The activation of the BM and spleen was significantly associated with inflammatory activity of the carotid artery.
- Received May 24, 2013.
- Accepted January 28, 2014.