Catheter Ablation of Atrial Fibrillation Raises the Plasma Level of NGF-beta Which Is Associated with Sympathetic Nerve Activity

PURPOSE: The expression of nerve growth factor-beta (NGF-beta) is related to cardiac nerve sprouting and sympathetic hyper innervation. We investigated the changes of plasma levels of NGF-beta and the relationship to follow-up heart rate variability (HRV) after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). MATERIALS AND METHODS: This study included 147 patients with AF (117 men, 55.8+/-11.5 years, 106 paroxysmal AF) who underwent RFCA. The plasma levels of NGF-beta were quantified using double sandwich enzyme linked immunosorbent assay method before (NGF-beta(pre)) and 1 hour after RFCA (NGF-beta(post-1hr)). HRV at pre-procedure (HRV(pre)), 3 months (HRV(post-3mo)), and 1 year post-procedure (HRV(post-1yr)) were analyzed and compared with plasma levels of NGF-beta. RESULTS: 1) The plasma levels of NGF-beta significantly increased after RFCA (20.05+/-11.09 pg/mL vs. 29.60+/-19.43 pg/mL, p18 pg/mL, low frequency components (LF)/high-frequency components (HF) (p=0.003) and the number of atrial premature contractions (APCs, p=0.045) in HRV(post-3mo) were significantly higher than those with < or =18 pg/mL. 3) The LF/HF at HRV(post-3mo) was linearly associated with the NGF-beta(pre) (B=4.240, 95% CI 1.114-7.336, p=0.008) and the NGF-beta(post-1hr) (B=7.617, 95% CI 2.106-13.127, p=0.007). 4) Both NGF-beta(pre) (OR=1.159, 95% CI 1.045-1.286, p=0.005) and NGF-beta(post-1hr) (OR=1.098, 95% CI 1.030-1.170, p=0.004) were independent predictors for the increase of LF/HF at HRV(post-3mo). CONCLUSION: AF catheter ablation increases plasma level of NGF-beta, and high plasma levels of NGF-beta(pre) was associated with higher sympathetic nerve activity and higher frequency of APCs in HRV(post-3mo).

Effect of Abciximab on the Levels of Circulating Microparticles in Patients with Acute Myocardial Infarction Treated by Primary Angioplasty

BACKGROUND AND OBJECTIVES: We investigated the effect of the additional use of abciximab during percutaneous coronary intervention (PCI) on the level of procoagulant microparticles (MPs) in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary PCI. SUBJECTS AND METHODS: In this study, we studied 86 patients with STEMI (72 men, age 58+/-13) who had undergone primary PCI. The decision to administer abciximab immediately prior to PCI was left to the discretion of the operator. Blood samples for analysis of MPs were obtained from the femoral artery before and after PCI. MPs with procoagulant potential were measured using a commercial kit. The cellular origins of MPs were determined by antigenic capture with specific antibodies. RESULTS: Procoagulant MPs captured onto annexin V were not changed significantly after PCI {13.4+/-13.2 nM vs. 13.2+/-16.1 nM phosphatidylserine equivalent (PS eq), p=0.479}. Abciximab was used in 30 of 86 patients (35%) immediately prior to PCI. In patients who had undergone PCI without abciximab, no significant change in the level of MPs was observed after PCI. However, in the abciximab group, the level of circulating MPs was significantly decreased after PCI (12.0+/-10.7 nM vs. 7.8+/-11.7 nM PS eq, p=0.018). Levels of endothelial- and platelet-derived MPs also showed a significant reduction after PCI in the abciximab group. CONCLUSION: Primary PCI with additional abciximab significantly reduced the level of procoagulant MPs regardless of their cellular origins in patients with STEMI.