OBJECTIVES/GOALS: Lung Ultrasound Congestion Score (LUS-CS) is a proposed measure for guiding treatment in acute heart failure (AHF). An emergency department (ED) pilot trial of LUS-guided diuresis showed reduced LUS-CS at 48 hours but no difference at hospital discharge or for clinical outcomes. We hypothesized total change in LUS-CS would predict adverse outcomes. METHODS/STUDY POPULATION: This was a post-hoc secondary analysis of the BLUSHED-AHF trial. BLUSHED-AHF was a pilot trial in which AHF patients were randomized to a LUS-guided diuresis strategy vs. usual care in the ED. The intervention was stopped after the ED course (i.e. during hospitalization). BLUSHED-AHF was designed for the intervention to target absolute values of LUS-CS over time, rather than change in LUS-CS from each patient’s baseline. We fit a cox regression model for a primary outcome of death or AHF rehospitalization, with total (ED to Hospital Discharge) change in LUS-CS as the primary predictor, adjusted for the Get-With-The-Guidelines heart failure risk score (GWTG). Survival curves were plotted, and hazard ratios calculated. RESULTS/ANTICIPATED RESULTS: 128 patients in BLUSHED-AHF were analyzed. Greater reduction in LUS-CS from ED to hospital discharge predicted event-free survival (HR = 0.74 for each 20 unit reduction in LUS-CS, 95%CI 0.56-0.99). This effect did not vary by hospitalization length or ED disposition. There was a significant interaction between change in LUS-CS and GWTG score (p DISCUSSION/SIGNIFICANCE: LUS-CS total change, and not absolute values, predict adverse events in LUS-guided diuresis. Post-ED cessation of the intervention in BLUSHED-AHF may have precluded opportunity for clinical benefit. Future trials should run the entire hospital course, target change from baseline, and consider patient selection by AHF severity and initial LUS-CS.