Plasma miR-451a predicts atrial fibrillation recurrence after pulmonary vein ablation

Background/Introduction Atrial fibrillation (AF) is the most common sustained arrhythmia diagnosed in European countries. Several studies have shown that catheter ablation is a more effective treatment than antiarrhythmic drugs and should be prioritised in symptomatic patients. However, AF recurrence after catheter ablation remains a challenge. MiRNAs have been identified, in recent years, as epigenetic modulators in numerous biological processes, including cardiac electric conduction. MiRNAs can be easily detected in the circulation, making them attractive as potential biomarkers for risk stratification in AF patients. Purpose Our purpose is to find a miRNA able to predict the AF recurrence after catheter ablation. Methods 44 patients submitted to catheter ablation were consecutively recruited and classified based on recurrence after a follow up of 12 to 48 months. Peripheral and left atrium blood samples were collected before catheter ablation. Human Cardiovascular Disease miScript miRNA PCR Arrays were performed to analyse 84 miRNAs altered in cardiovascular disease. Significant miRNAs changes in ΔCt levels were assessed using Two-way ANOVA and post hoc Tukey tests. Simple logistic regression analysis was performed to analyse association to AF recurrence. KEGG pathway enrichment analysis was performed to identify the most enriched targets and pathways involved in AF recurrence. Results In our cohort, overall recurrence rate was 47.7%. qPCR expression analysis showed increased levels of miR-328-3p and decreased levels of miR-486-5p in recurrent patients, both in peripheral as well as left atrial blood. Our results also showed decreased levels of miR-let-7b-5p and miR-451a in recurrent patients, but selectively regulated in peripheral and atrial blood, respectively (Figure 1). Simple logistic regression analysis showed a significant association between blood atrial levels of miR-451a and AF recurrence (Figure 2A). KEGG pathway enrichment analysis showed that miR-451a could be involved in epigenetic regulation of myocardial electromechanic integrity (Figure 2B). Conclusion Expression analysis of atrial blood miR-451a levels, prior to catheter ablation, could be a good a risk stratifier of recurrence. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): IN607A2019/02. Xunta of Galicia. Grants for the consolidation and structuring of competitive research units in the universities of the Galician University System, in the public research organizations of Galicia and in other entities of the Galician R&D System 2019