Abstract 3315: Systemic Inflammatory Changes After Pulmonary Vein Radiofrequency Ablation do not Alter Stem Cell Mobilization
Introduction: Acute myocardial infarction is followed by enhanced mobilization of bone marrow derived stem cells. Since stem cell mobilization might contribute to a more favorable outcome the analysis of stem cell mobilizing factors is of particular clinical importance. In addition to myocardial ischemia tissue necrosis may contribute to stem cell mobilization. Aim of this study, therefore, was to analyze myocardial necrosis, systemic inflammatory changes and the number of circulating stem cells after pulmonary vein radiofrequency (RF) ablation.
Methods: Blood samples from 13 Patients with paroxysmal atrial fibrillation were collected before and one day after pulmonary vein RF ablation. The cardiac enzymes creatine kinase (CK) and Troponin T (TnT) were analyzed to asses myocardial necrosis, C-reactive protein (CRP), Interleukin (IL)-6, IL-8, IL 10, IL-12 and SDF-1 were used as a measure for systemic inflammatory changes. CD133+ and CD117+ stem cells were quantified using flow cytometry and early outgrowth endothelial progenitor cells were analyzed 7 days after culture in endothelial medium.
Results: The mean number of RF-applications was 75±30 and mean duration of RF-ablation time was 3010 ± 1604 seconds. The following day after the procedure a significant increase in mean CK and TnT levels from 117 ± 50 to 203 ± 106 U/l (p=0.007) and 0.01 to 1.19 ± 0.86 ng/ml (p=0.003) respectively was observed. Mean CRP level rose from 2.4 ± 2.9 to 20.10 ± 9.19 mg/l (p<0.0001) accompanied by an isolated increase in IL-6 (p=0,007) that positively correlated with the increase of TnT (p=0.0018). SDF-1 levels decreased significantly (p=0.004) and negatively correlated with corresponding TnT plasma levels. Yet, no significant changes were observed in IL-8, IL 10 and IL-12 plasma levels as well as in the number of circulating CD133+ or CD117+ stem cells or endothelial progenitor cells.
Conclusion: Although pulmonary vein RF ablation induces significant myocardial necrosis that is accompanied by a systemic IL-6 associated inflammatory reaction and a decrease in SDF-1 plasma levels no alterations in stem cell mobilization were observed. Thus, isolated myocardial necrosis may not be sufficient to account for the stem cell mobilization observed in acute myocardial infarction.