Abstract 4367418: Longer Door-to-Diuretic Time Is Associated with Increased In-Hospital Mortality among Acute Decompensated Heart Failure: Analysis of a Multi-Center Contemporary Cohort

Background: Diuretic administration is a cornerstone of acute decompensated heart failure (ADHF) treatment. Prior research suggest that delays in initial therapy in the emergency department may be linked to higher risk of in-hospital mortality, but this has not been examined in large contemporary cohorts and in the context of guideline directed medical therapy (GDMT). Methods: We analyzed ADHF hospitalizations from 2013-2020 across two large health systems in New York (University of Rochester) and Texas (Baylor, Scott&White). Inclusion criteria were age ≥18, a primary diagnosis of ADHF, and intravenousbadministration of loop diuretics within 16 hours of admission. Door-to-diuretic (D2D) time was calculated in hours as the time between hospital arrival and administration of the first IV loop diuretic. The primary outcome was in-hospital mortality. We fit a logistic regression (LR) model adjusting for gender, number of hospital beds, and Get With the Guidelines-HF (GWTG-HF) risk score. Subgroup analysis for patients with EF ≤ 35% included GDMT score (ACE/ARB/ARNI, beta-blocker, mineralocorticoid receptor antagonist, SGLT2 inhibitor, 1 point for each). We fit a Kaplan-Meir curve for time-to-event analysis and visualized survival by D2D quartiles. Analyses were performed in R (version 4.4.0)with p<0.05 set for significance. Results: Our cohort included 14,448 patients (52.2%, n = 7,544 female; 78.0%, n = 11,268 White; 92.4%, n = 13,356 non-Hispanic) with a mean age of 72.9 ± 14.2 years. D2D time was 8.7 ± 4.7 hours, with only 2.1% (n = 308) of patients receiving diuretics within the first hour. In the LR model, each additional hour of D2D time was associated with a 3.8% increase in the odds of in-hospital mortality (OR = 1.038, 95% CI: 1.024-1.053, p < .001). Patients in the fastest quartile of D2D time had the highest survival probability across the hospital stay (p < .01; Figure 1). Sensitivity analysis in the EF ≤ 35% subgroup confirmed that D2D time remained a significant predictor of in-hospital mortality (OR = 1.064, 95% CI: 1.026-1.106, p = .001) despite GDMT use. Conclusion: Shorter D2D time is associated with lower in-hospital mortality in ADHF, after adjusting for clinical risk and hospital-level factors. While the effect size per hour is modest, cumulative delays may meaningfully increase mortality risk. These findings support prioritizing early IV diuretic initiation in ADHF care, and a prospective trial is warranted.