Novel biomarkers in cardiology: MicroRNAs in atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained chronic cardiac arrhythmia in clinical practice, which increases the risk of stroke and thromboembolism and is an independent predictor of mortality. The underlying mechanisms involved in the development of AF have yet to be fully elucidated. However, once initiated, AF tends to self-perpetuate, owing to structural and electrical remodeling in the atria. MicroRNAs (miRNAs) represent a sizable sub-group of small non-coding RNAs, which degrades or inhibits the translation of their target mRNAs, thus regulating gene expression and playing an important role in a wide range of biologic processes. Clinically, there is increasing evidence of the potential diagnostic role of miRNAs as biomarkers, representing a novel therapeutic target in AF. The aim of this review is to provide an exhaustive overview of the role of miRNAs in AF and to discuss the diagnostic and therapeutic potential of miRNAs in this arrhythmia.