Association of apelin and AF in patients with implanted loop recorders undergoing catheter ablation

Previous studies showed an association between apelin and atrial fibrillation (AF). The aim of this study was to analyse the effect of pulmonary vein isolation (PVI) in patients with paroxysmal AF on plasmatic apelin concentrations. Nine consecutive patients (aged from 43 to 69 years, 3 females and 6 males) with documented paroxysmal atrial fibrillation and implanted loop recorders (ILR) for continuous ECG monitoring were included in this study. All the patients underwent a radiofrequency catheter ablation with PVI. The plasmatic concentration of apelin increased after PVI. The average plasmatic concentration of apelin before PVI was 0.299 ng/ml (±0.16), 3 months after PVI 0.462 ng/ml (±0.10) and 9 months after PVI 0.565 ng/ml (±0.146). There was an increase in the concentration of apelin 3 months and 9 months after the PVI by 0.163 ng/ml (p=0.07) and by 0.266 ng/ml (p=0.01), respectively. The concentration of apelin inversely correlated with the AF burden (r=-0.44, p=0.03). Our study showed a significant increase in apelin levels after the reduction of AF burden via PVI and an inverse correlation with AF burden. Apelin might be a promising marker of AF (Tab. 2, Fig. 2, Ref. 28).