Oral Abstract Session: Translational view on atrial fibrillation

Radiofrequency (RF) catheter ablation is an accepted and widely used method in the invasive therapy of cardiac arrhythmias.Continuous, low voltage AC power is delivered through the tip of the catheter causing local thermal injury and irreversible necrosis.Our aim was to characterize the inflammatory reaction following RF ablation focusing on neutrophil migration and activation of the matrix metalloproteinase system.In this prospective study we included 39 patients who underwent RF ablation (atrial fibrillation n=12, typical atrial flutter n=14, AV-nodal reentry tachycardia n=13) and 12 patients who underwent cardiac electrophysiology study (EPS) without ablation.Blood samples were taken before, immediately after, as well as 4, 20 hours and 3 months after the procedure.The following biomarkers were determined: interleukin-6 (IL-6), C-reactive protein (CRP), sP-selectin, intracellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MCP-1), polymorphonuclear elastase (PMN-elastase), matrix-metalloproteinase-9 (MMP-9), creatine-kinase MB (CK-MB), high sensitivity troponin-T (hsTnT).After RF ablation we found immediate increase in IL-6 ( p , 0.0001), which was followed by elevation of CRP at 20 hours ( p , 0.0001).After an immediate drop in sP-selectin levels ( p=0.0038), ICAM-1 concentrations increased at 20 hours and remained elevated at 3 months post-procedure ( p , 0.0001).MCP-1 levels decreased, while PMN-elastase levels increased at 4 hours and 20 hours post-ablation respectively and remained elevated at 3 months (p , 0.0001 and p=0.0002, respectively).MMP-9 increased at 4 hours after the procedure and was elevated at the follow-up control ( p , 0.0001).We found a marked elevation in CK-MB (p , 0.0001) and hsTnT ( p , 0.0001) levels in the first 20 hours following RF ablation, while both decreased to baseline at 3 months.In the EPS group IL-6 increase was not followed by elevation of other inflammatory markers and a slight increase in hsTnT was observed.RF catheter ablation induces systemic inflammatory response reflected by the elevation of IL-6 and CRP.Leukocyte rolling and adhesion might be increased at the local laesion site, indicated by the changes in adhesion molecules P-selectin, ICAM-1 and the chemo-attractant MCP-1, while activation is reflected by PMN-elastase.Immediate activation of MMP-9 was also induced.According to our results activation of neutrophils and the matrix metalloproteinase system might still be present 3 months following RF ablation.