A cardiac ejection fraction of 20 belongs to heart failure with reduced ejection fraction, which can generally increase or even return to normal as the heart failure improves. The current guidelines for the treatment of heart failure recommend the use of the “new quadruple” drug therapy, including angiotensin receptor enkephalinase inhibitor (ARNI)/angiotensin-converting enzyme inhibitor (ACEI)/angiotensin II receptor antagonist (ARB), β-receptor antagonist, aldosterone receptor antagonist, SGLT2i. 1.ARNI/ACEI/ARB: By inhibiting the RAAS system, reduce the adverse effects caused by the excitation of neurohumoral compensatory mechanisms in patients with heart failure, delay the progression of heart failure and improve ventricular remodeling. Such as sacubitril valsartan/perindopril/alisartan, etc. 2. β-receptor antagonist: inhibit the unfavorable effects produced by sympathetic activation, reduce myocardial oxygen consumption, improve symptoms and prognosis. For example, metoprolol, bisoprolol, etc. 3. Aldosterone receptor antagonists: can inhibit cardiac remodeling, improve the long-term prognosis of patients with heart failure. Such as spironolactone, eplerenone, etc. 4.SGLT2i: It has the effects of weight reduction and blood pressure lowering, and has clear cardiovascular benefits for patients with heart failure, especially for those with diabetes mellitus. Such as dagliflozin, engliflozin, and so on. Clinically, according to the patient’s heart failure specifics, there is no combination of other diseases and / or complications, such as the choice of drugs, often combined with the use of diuretics to improve the patient’s heart failure symptoms, the drug needs to comply with the doctor’s instructions for rational application.