Cardiac rehabilitation can be useful in clinically stable patients with HF to improve functional capacity, exercise duration, health-related quality of life, and mortality (155,157,158,163 166). (Level of Evidence: B) 6.3.2. Pharmacological Treatment for Stage C HFrEF CLASS I 1. Measures listed as Class I recommendations for patients in stages A and B are recommended where appropriate for patients in stage C. (Levels of Evidence: A, B, and C as appropriate) 2. GDMT as depicted in Figure 1 should be the mainstay of pharmacological therapy for HFrEF (134,136,137,167 182). (Level of Evidence: A) See Table 10 for oral diuretics recommended for use in the treatment of chronic HF. CLASS I 1. Diuretics are recommended in patients with HFrEF who have evidence of uid retention, unless contraindicated, to improve symptoms. (Level of Evidence: C) 6.3.2.2. ACE INHIBITORS See Table11for drugs commonlyusedfor HFrEF(stage C HF). CLASS I 1. ACE inhibitors are recommended in patients with HFrEF and current or prior symptoms, unless contraindicated, to reduce morbidity and mortality (134,167 169). (Level of Evidence: A) Table 9. 