Association of Serum Biomarkers and Cardiac Inflammation in Patients With Atrial Fibrillation: Identification by Positron Emission Tomography.

Background: Peripheral biomarkers may be affected by various factors, their reliability in reflecting local cardiac inflammatory status in patients with atrial fibrillation (AF) needs further exploration. This prospective study was aimed to investigate the relationship between circulating biomarkers and local cardiac inflammation measured by epicardial adipose tissue (EAT) activity via (18)F-fluorodeoxyglucose (FDG) imaging in AF patients. Methods: From 2017 to 2018, 83 AF patients [43 persistent AF (PsAF) and 40 paroxysmal AF (PAF)] referred for radiofrequency catheter ablation (RFCA) were recruited. Pre- and post-RFCA blood samples were collected to measure IL-6, IL-8, IL-10, IL-18, TNF-α, Hsp27, Hsp60, Hsp70, PDGF-BB, MMP-2, MMP-9, MPO, TGF-β1, Gal-3, and sST2. Pre-RFCA FDG images were obtained to assess EAT activity. Sixty-seven patients (35 PAF and 32 PsAF) received RFCA were regularly followed for 27 (24, 29) months. Results: Higher hsCRP and IL-6 and lower TGF-β1 were demonstrated in PsAF patients compared with PAF patients. Multivariate logistic regression analysis demonstrated that Gal-3 (OR: 1.221, 95% CI: 1.024-1.456, P = 0.026) and MPO (OR: 1.002, 95% CI: 1.001-1.003, P = 0.027) were independently correlated with EAT activity. The percentage decrease of Hsp60 linearly correlated with that of EAT activity post-RFCA (Spearman r (s) = 0.455, P = 0.019). Seventeen patients (10 PsAF and 7 PAF) had AF recurrence, but none of the selected biomarkers were predictive of post-RFCA recurrence. Conclusion: Our findings demonstrated that in patients with AF, Gal-3 correlated with local cardiac inflammation, and Hsp60 was associated with the alleviation of cardiac inflammation after RFCA.