Abstract 18505: Atrial Fibrillation Ablation May Suppress Systemic Inflammatory Activation by Inhibiting Thioredoxin Interacting Protein Expression
Introduction: Atrial fibrillation (AF) is characterized by inflammatory activation and impaired tissue responsiveness to nitric oxide (NO). Both these processes may contribute to perpetuation of AF and embolic risk. At this stage, it is uncertain whether AF ablation exerts effects on these pathogenic processes, despite the implication of restoration of sinus rhythm and consequently laminar flow.
Hypothesis: We therefore tested the hypothesis that ablation of AF suppresses expression of myeloperoxidase (MPO) and thioredoxin interacting protein (TXNIP), both of which potentially contribute to inflammation and redox stress. It is known that non-laminar flow is a stimulus for increased TXNIP expression. Furthermore, we determined whether there was associated sensitization of tissues to NO, as might be expected with withdrawal of these inflammatory mediators.
Methods: Patients (n=19) with AF scheduled for elective ablation were studied. MPO expression in plasma was assessed by ELISA, platelet TXNIP content by immunohistochemistry, and reversal of adenosine diphosphate (ADP)-induced aggregation by NO donor sodium nitroprusside (SNP) utilizing whole blood platelet aggregometry. Analysis was via intention-to-treat.
Results: Of the 19 patients studied, mean patient age was 70±11 years, and 15 patients had paroxysmal AF. Over a 6-month follow-up period, 16 patients (79%) remained in sinus rhythm. Effects on inflammatory markers are summarized in the table and graphs.
Conclusions: 1. AF ablation induces prolonged suppression of TXNIP expression, possibly related to reduction of shear stress, leading to dimunition of redox stress post AF ablation. 2. However, at 6 months there was no significant suppression of MPO expression, or restoration of tissue responsiveness to NO.
Author Disclosures: V. Goh: None. C. Woolley: None. A. Awford: None. N. Procter: None. C. Chong: None. S. Liu: None. Y.Y. Chirkov: None. J. Hii: None. J.D. Horowitz: None.
- © 2016 by American Heart Association, Inc.