Serum neuron-specific enolase, a marker of neuronal injury, increases after catheter ablation of atrial fibrillation

Catheter ablation of atrial fibrillation (AF), targeting isolation of pulmonary veins (IPV), is an effective therapeutic approach particularly for patients with paroxysmal AF.1,2 However, this procedure can lead to some complications, one of the most striking of which is the occurrence of stroke in 1% of patients.3 Additionally, periprocedural diffusion-weighted cerebral magnetic resonance imaging (DW-MRI) has shown that the IPV procedure can lead to subclinical cerebral embolism in up to 48% of patients.4–8 Previous studies have been performed to evaluate silent cerebral lesions during IPV using DW-MRI as a reference diagnostic method. However, another study suggested that DW-MRI lacks sensitivity, and the authors investigated whether detection of cerebral damage during IPV can be improved by assessing a sensitive biomarker of neuronal injury: protein S100B.9 The authors found that a higher incidence of silent stroke can be revealed by the biomarker-based (protein S100B) approach than by DW-MRI alone. 9 Neuron-specific enolase (NSE) is also a serum biomarker of neuronal injury with a biologic half-life of approximately 24 h. It is an intracytoplasmic enzyme located in neurons and neuroectodermal cells. If neuronal injury occurs and the integrity of the blood–brain barrier is impaired, NSE is released into the cerebrospinal fluid and then into the blood. An increased serum NSE level in the cerebrospinal fluid and blood reportedly has high predictive value in neurocognitive damage or neurological outcomes after stroke, cardiovascular surgery, and cardiac arrest.10–14 However, the literature presents insufficient data about the association between an increased NSE and neurological outcomes during IPV. This preliminary study was performed to assess the changes in the serum NSE level, which is assumed to be an indicator of neuronal damage, in patients undergoing catheter ablation for AF. To the best of our knowledge, no previous studies have investigated the alterations in the serum NSE level during and after the IPV procedure.