For previous studies,[6–13,17,18] risk factors for the development of new-onset AF included age, female sex, obesity, Killip class or heart failure, CHADS2 score, creatinine kinase, C-reactive protein, N-terminal pro-brain natriuretic peptide, levels of left ventricular ejection fraction and left atrium diameter. The gene discussed is CRP; the disease is atrial fibrillation.