Impaired mobilization of bone marrow derived CD34 positive mononuclear cells is related to the recurrence of atrial fibrillation after radiofrequency catheter ablation

Abstract

Background: We have reported previously that non-ischemic titrated cardiac injury by radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) mobilizes bone marrow derived CD34+ mononuclear cells. We hypothesized that the degree of post-RFCA CD34+ cell mobilization affects the clinical outcome of AF ablation. Methods and Results: Fifty-six patients (39 males, 53 +/- 13 years) who underwent electrophysiology study (EPS; n=10) or RFCA of AF (n=46) were included. The peripheral blood CD34+ cell count and multiple serologic markers were evaluated before, immediately after the procedure. Results: 1. The percent increase of CD34+ cells (%Delta CD34+) was significant after RFCA as compared to EPS (p<0.01). 2. The post-RFCA CD34+ cell count was significantly higher in patients who underwent RF energy delivery >= 80 min than those <80 min (p=0.024). 3. The %Delta CD34+ was linearly correlated with the plasma level of troponin I (R=0.38, p<0.01), but not with the non-ablation procedure time (p=NS). 3. During 30.2 +/- 2.7 months follow-up, AF recurred in 37% of patients including early recurrence (34.8%). In contrast, the patients in whom AF recurred received a longer duration of RF energy delivery than those remaining in sinus rhythm (p=0.04), they were associated with lower %Delta CD34+ (p=0.02). Conclusion: CD34+ mononuclear cells were mobilized after catheter ablation by RF energy dose dependent manner, and the duration of RF energy delivery was longer in patients with AF recurrence. However, CD34+ mononuclear cell mobilization was significantly impaired in patients with recurring AF after RFCA. (C) 2011 Elsevier Ireland Ltd. All rights reserved.