Is the Cell-Free Circulating Mitochondrial DNA a Potential Biomarker for Atrial Fibrillation?

: Atrial fibrillation (AF), considered the most common tachyarrhythmia, is associated with severe complications, such as ischemic stroke and heart failure. Mitochondria are organelles that supply cells energy by converting various forms of molecules into adenosine triphosphate. Mitochondria has a double-stranded, independent DNA (mtDNA), the copy number of which in peripheral blood is associated with the oxidative stress status in the patient. Oxidative stress is also regarded as a potential factor contributing to AF. This study reviews the association between the cell-free circulating mitochondrial DNA (Cfc-mtDNA) in peripheral blood and AF. We searched for studies on AF and mtDNA; four investigations were included. The three of these studies revealed that the level of Cfc-mtDNA in serum appears to be associated with AF, but there are no similar results about Cfc-mtDNA and Per-AF. In addition, the age and gender of patients do not affect Cfc-mtDNA levels. However, further research is necessary in the future.