A number of medications including ACE inhibitors, ARBs, β-blockers, mineralocorticoid receptor antagonists (MRAs), and the combination of hydralazine/isosorbide dinitrate (in black patients) have been shown, in prospective randomized placebo-controlled clinical trials, to improve symptoms, decrease mortality and decrease hospitalization in ambulatory patients with heart failure with reduced ventricular systolic function (Taylor et al., N Engl J Med 351(20):2049, 2004; N Engl J Med 325(5):293, 1991; N Engl J Med 316(23):1429, 1987; Heran et al., Cochrane Database Syst Rev (4):CD003040, 2012; Granger et al., Lancet 362(9386):772, 2003; Cohn and Tognoni, N Engl J Med 345(23):1667, 2001; Packer et al., N Engl J Med 344(22):1651, 2001; Hjalmarson et al., JAMA 283(10):1295, 2000; Lancet 353(9146):9, 1999; Pitt et al., N Engl J Med 348(14):1309, 2003; Pitt et al., J Am Coll Cardiol. 46(3):425, 2005). Randomized studies of these agents have not been conducted in patients hospitalized for ADHF. The ACCF/AHA guidelines recommend that heart failure medications be carefully reviewed on admission and that appropriate changes be made during hospitalization. Chronic maintenance therapy with guideline-directed medical therapy (GDMT) should, in general, be continued during hospitalization for ADHF and GDMT should be initiated in patients with ADHF and HFrEF who are not receiving chronic heart failure medications (Yancy et al., Circulation 128(16):e240, 2013). The HFSA guidelines emphasize that hospitalization for ADHF is an “excellent opportunity” to optimize a patient’s chronic oral medical regimen (Lindenfeld et al., J Card Fail 16(6):e131, 2010). The ESC guidelines recommend that GDMT should be continued on admission or should be started as soon as possible in patients with HFrEF (Collins et al., Ann Emerg Med 47(1):13, 2006).