CIBIS: Cardiac Insufficiency Bisoprolol Study, HFrEF: Heart Failure with reduced Ejection Fraction, NYHA: New York Heart Association, LVEF: Left Ventricular Ejection Fraction, CHF: Chronic Heart Failure, ACEi: Angiotensin Converting Enzyme inhibitor, ARB: Angiotensin Receptor Blocker, BB: β Blocker, QD: Once a day, BID: Two times a day, HR: Hazard ratio, (HR <1.0 indicates reduced risk over time in the treatment group compared to control). Here, ACE is linked to congestive heart failure.