Association between serum inflammatory biomarkers and atrial low voltage in patients with atrial fibrillation: A phase 1 FIB-MARK study

Background The mechanisms leading to atrial fibrosis in patients with atrial fibrillation (AF), especially in relation to inflammation, remain unclear. Methods and Results Forty biomarkers were measured in peripheral blood samples collected prior to catheter ablation, and the association with left atrial (LVZ) was evaluated in 16 consecutive patients. The median %LVZ was 17%. In Pearson's correlation analysis, interleukin(IL)-17A and interferon(IFN)-γ showed the most significant positive and negative correlations with %LVZ (R = 0.35 and 0.43, P < 0.001). Furthermore, the IL-17A/IFN-γ ratio was significantly associated with %LVZ (R = 0.65, P = 0.007), as was the macrophage inflammatory protein (MIP)-1δ/IFN-γ ratio (R = 0.73, P = 0.001). The area under the receiver operator characteristics curves of the IL-17A/IFN-γ and MIP-1δ/IFN-γ ratios for detecting severe LVZ (%LVZ ≥ 10% as a reference standard) were 0.88 and 0.90, respectively. The IL-17A/IFN-γ ratio was significantly higher in patients with severe LVZ than those without (1.41 versus 0.97, P = 0.01). Furthermore, the sensitivity, specificity, and accuracy for detecting severe LVZ were 60%, 100%, and 75.0%, respectively, at a cut-off value of 1.3. Conclusions Among inflammatory biomarkers, the serum IL-17A/IFN-γ ratio was associated with severe left atrial LVZ in patients with AF. However, further studies are needed to clarify the role of inflammatory biomarkers in the development and progression of atrial fibrosis in patients with AF.