Prevalence of atrial FDG uptake and association with atrial arrhythmias in patients with cardiac sarcoidosis.

Abstract Background There is increasing evidence that a proportion of patients with cardiac sarcoidosis (CS) have atrial arrhythmias (AA). Although 18F-fluorodeoxy-glucose (FDG) uptake in the ventricle on positron emission tomography/computed tomography (PET/CT) is well studied, FDG uptake in the atrium has not been elucidated in detail. Objectives To evaluate FDG uptake in the atrium and its relationship with AA in patients with CS. Methods We retrospectively investigated 62 CS patients. All patients underwent echocardiography and PET/CT. Serum angiotensin converting enzyme (ACE) and soluble IL-2 receptor (sIL-2R) levels, plasma N-terminal pro–brain natriuretic peptide (NT-proBNP) concentrations were also evaluated. ECG, Holter monitoring and device interrogations were used to detect AA. Results Of the studied population, 25 patients (40.3%) had AA, of which 2 patients had atrial tachycardia (AT) and 23 patients had atrial fibrillation (AF). Eighteen patients with AA had atrial FDG uptake on PET/CT, whereas 14 patients without AA had atrial FDG uptake (72.0% vs 37.8%, P = 0.017). Multivariate analysis revealed a significant association between AA and age (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 1.01–1.31, P = 0.040), atrial FDG uptake (odds ratio [OR]: 7.23; 95% confidence interval [CI]: 1.91–27.36, P = 0.004), and left atrial diameter (OR: 1.08; 95% CI: 1.01–1.16, P = 0.027). Meanwhile, gender, serum ACE and BNP levels, and left ventricular ejection fraction were not associated with AA. Conclusions Atrial FDG uptake was common in patients with CS and strongly associated with AA.