Although numerous clinical studies have identified numerous plausible predictors (male sex, left atrial volume index, left ventricular end diastolic dimension, anemia, neutrophil count, the levels of myokines/hepatokines including irisin and adropin, glomerular filtration rate, creatinine, pre-existing kidney failure, atrial fibrillation, diabetes mellitus) for these patients [15,16,17,18,19], reliable predictors corresponding with this clinical presentation remain to be discussed scientifically. This evidence concerns the gene FNDC5 and atrial fibrillation.