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 (%ΔCD34+) 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 %ΔCD34+ 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 %ΔCD34+ (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.