BackgroundCardiology has advanced guideline development and quality measurement. Recognizing the substantial benefits of guideline‐directed medical therapy, this study aims to measure and explain apparent deviations in heart failure (HF) guideline adherence by clinicians at hospital discharge and describe any impact on readmission rates.Methods and ResultsThe extent of decongestion and prescription of neurohormonal therapy were recorded prospectively for 226 HF discharges, including 132 (58%) from an academic hospital and 94 (42%) from a community hospital. Among all discharges, 25% were discharged with residual congestion (30% academic versus 18% community, P=0.070). Among discharges of patients with HF with reduced ejection fraction, 37% (45% academic versus 18% community, P<0.001) were discharged without β‐blocker therapy or with lower doses than at admission. Moreover, 46% of patients with HF with reduced ejection fraction (48% academic versus 39% community, P=0.390) were discharged without an angiotensin‐converting enzyme inhibitor or angiotensin II receptor blocker or with lower doses than at admission. Renal dysfunction was the most common reason for discharge with congestion, and hypotension the most common reason for discharge with no or decreased neurohormonal therapy. There was a trend toward higher 90‐day readmission rates after discharge with residual congestion.ConclusionsClinicians frequently deviate from guidelines in both academic and community hospitals; however, this deviation may not always indicate poor quality. Application of guidelines recommended for stable populations is increasingly limited for hospitalized patients by hypotension, renal dysfunction, and inotrope use. Patients with renal dysfunction, hypotension, and recent inotrope use merit further study to determine best practices and possibly to adjust quality metrics for HF severity.