The Hospitalized Patient: Recommendations See Table 22 for a summary of recommendations from this section and Figure 4 for the classi cation of patients presenting with acutely decompensated HF. Figure 3. Stages in the development of HF and recommended therapy by stage. ACEI indicates angiotensin-converting enzyme inhibitor; AF, atrial brillation; ARB, angiotensin-receptor blocker; CAD, coronary artery disease; CRT, cardiac resynchronization therapy; DM, diabetes mellitus; EF, ejection fraction; GDMT, guideline-directed medical therapy; HF, heart failure; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; HRQOL, health-related quality of life; HTN, hypertension; ICD, implantable cardioverter-de brillator; LV, left ventricular; LVH, left ventricular hypertrophy; MCS, mechanical circulatory support; and MI, myocardial infarction. Adapted from Hunt et al (37). zAlthough optimal patient selection for MCS remains an active area of investiga- tion, general indications for referral for MCS therapy include patients with LVEF <25% and NYHA class III IV functional status despite GDMT, including, when indicated, CRT, with either high predicted 1- to 2-year mortality (e.g., as suggested by markedly reduced peak oxygen consumption and clinical prognostic scores) or dependence on continuous parenteral inotropic support. Patient selection requires a multidisciplinary team of experienced advanced HF and transplantation cardiologists, cardiothoracic surgeons, nurses, and ideally, social workers and palliative care clinicians. Yancy et al. JACC Vol. 62, No. 16, 2013 2013 ACCF/AHA Heart Failure Guidelines: Executive Summary October 15, 2013:1495 539 7.1. Precipitating Causes of Decompensated HF CLASS I 1. ACS precipitating acute HF decompensation should be promptly identi ed by electrocardiogram and serum biomarkers, including cardiac troponin testing, and treated optimally as appropriate to the overall condition and prog- nosis of the patient. (Level of Evidence: C) 2. 