Each of the 11 studies was carefully analyzed to determine the primary outcomes of ivabradine on LVEF and HR, while also making sure to note secondary outcomes: quality of life (QoL), brain natriuretic peptide (BNP) levels, N-terminal pro-hormone of brain natriuretic peptide (NT-proBNP), exercise capacity, heart failure readmission, CVD mortality, asymptomatic bradycardia, and atrial fibrillation. The gene discussed is NPPB; the disease is atrial fibrillation.