Abstract Body (Do not enter title and authors here): Background: Magnet® designated hospitals demonstrate excellence in nursing practice. Acute decompensated heart failure (ADHF) is a critical condition characterized by the sudden worsening of heart failure symptoms, leading to high in-hospital mortality and extended hospital stays. While prior studies have linked Magnet status to better general patient outcomes, its specific impact on ADHF management remains underexplored. This study aims to investigate whether Magnet designation independently predicts lower in-hospital mortality and shorter length of stay (LOS) for patients admitted with ADHF.

Methods: We conducted a retrospective analysis of ADHF hospitalization between 2013-2020 across two large hospital systems in New York and Texas. Eligible cases included adults aged 18 or older with ADHF who received intravenous loop diuretics < 24 hours of admission. Magnet designation was assessed at the hospital level. Two multilevel models were used: a logistic mixed-effects model to compute odds ratio (OR) for in-hospital mortality and a linear mixed-effects model to compute β for LOS. Both models included fixed effects for Magnet status, sex, ethnicity, year of admission, number of hospital beds, guideline-directed medical therapy (GDMT), Get with The Guidelines–Heart Failure (GWTG-HF) score, and Modified Charlson Comorbidity Index. Random intercepts were included for subject and hospital. All continuous predictors were standardized prior to model entry. Analyses were conducted in R (version 4.3.1) using packages lme4, lmer, and bobyqa .

Results: The cohort included 26,004 ADHF patients (52.7% female; 79.2% White, 91.0% non-Hispanic), with mean age of 73+14 years and 28.3% of hospitalizations occuring at Magnet-designated hospitals. After adjusting for covariates, Magnet designation was associated with significantly lower odds of in-hospital mortality (OR = 0.21, 95% 0.06–0.78, p = 0.012). Mortality risk increased with higher GWTG-HF scores (p = 0.006). Magnet status was not associated with LOS (β = –3.18, p = 0.96). Longer LOS was observed in hospitals with more beds (β = 3.08, p < 0.001), and among patients with higher GDMT (β = 5.56, p < 0.001) and GWTG-HF scores (β = 6.24, p < 0.001).

Conclusion: Magnet designation was significantly associated with lower in-hospital mortality but not with shorter LOS among ADHF patients. These findings suggest that while Magnet hospitals may improve survival outcomes through high-quality care processes.