Association between infection and mortality in acute heart failure in the emergency department: a cohort study

BACKGROUND AND IMPORTANCE: Acute heart failure (AHF) is a frequent cause of emergency department (ED) admissions, yet the prognostic impact of infection as a trigger remains insufficiently characterized. OBJECTIVE: To evaluate the impact of infection as a trigger of AHF on in-hospital mortality and postdischarge survival. DESIGN: Retrospective observational cohort study. SETTINGS AND PARTICIPANTS: All adult patients presenting with AHF to the ED of Strasbourg University Hospital in 2020 were included. Clinical and outcome data were collected from 1296 ED visits. INTERVENTION OR EXPOSURE: Infection and other AHF triggers were defined through adjudication based on clinical, imaging, and microbiological data collected throughout the hospital stay. OUTCOME MEASURES AND ANALYSIS: The primary outcome was in-hospital mortality. Analyses were performed using inverse probability weighting (IPW). Postdischarge survival was assessed using IPW-weighted Kaplan-Meier estimates and Cox models. MAIN RESULTS: Infection was identified in 119 ED visits [9.2%, 95% confidence interval (CI): 7.7-10.9]. Patients with infection had higher in-hospital mortality than those without infection (30.3% vs. 9.0%, P < 0.001). In IPW-weighted analyses, infection was independently associated with in-hospital mortality [odds ratio (OR) = 2.76, 95% CI: 1.64-4.66]. In contrast, atrial fibrillation (OR = 0.45, 95% CI: 0.23-0.87) and acute coronary syndrome (OR = 0.08, 95% CI 0.01-0.58) were associated with lower in-hospital mortality. Infection was also associated with reduced postdischarge survival (hazard ratio = 1.64, 95% CI: 1.14-2.37, P = 0.008). CONCLUSION: Infection is a strong and independent predictor of short- and long-term mortality in patients presenting with AHF in the ED.