Heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF, hef-REF) is a form of heart failure in which the ejection fraction is reduced.^[1] This is defined as a left ventricular ejection fraction (LVEF) of 40% or less. About half of heart failure patients have a reduced ejection fraction.^[2] Other types of heart failure are heart failure with mildly reduced ejection fraction (LVEF between 40% and 50%) and heart failure with preserved ejection fraction (LVEF 50% or higher).^[1][3]