Predictive Factors of 30-day Adverse Events in Acute Heart Failure after Discharge from Emergency Department; a Historical Cohort Study

Introduction: The rates of unscheduled emergency department (ED) visits and readmissions after discharge from the ED in acute heart failure (AHF) patients are high. This study aimed to identify the predictive factors of 30-day adverse events after discharge from the ED.Methods: A retrospective study was conducted from2017 to 2019 in patients diagnosed with AHF and discharged from the ED at a tertiary university hospital. Thirty-day adverse events were defined as (i) unscheduled revisit to the ED with AHF, (ii) hospital admission from AHF, and, (iii) death after discharge from the ED. The predictive factors of 30-day adverse events were examined using multivariate analyses by logistic regression. Results: 421 patients with the median age of 73 (IQR: 63-81) years were studied (52.3% male). 81 (19.2%) patients had 30-day adverse events. Significant predictive factors of 30-day adverse events consisted of underlying valvular heart disease (OR = 2.46; 95%CI: 1.27-4.78; p = 0.008), chronic obstructive pulmonary disease (COPD) (OR = 0.08; 95%CI: 0.01-0.64; p=0.001), malignancy (OR=3.63; 95%CI: 1.17-11.24; p = 0.031), New York Heart Association functional class III (OR = 4.88; 95%CI: 0.93-25.59) and IV (OR = 7.23; 95% CI: 1.37-38.08) at the ED (p = 0.035), and serumsodium <135mmol/L (OR = 2.20; 95%CI: 1.17- 4.14; p = 0.014). Precipitating factors were anemia (OR = 2.42; 95%CI: 1.16-5.02; p = 0.021), progressive valvular heart disease (OR = 3.52; 95%CI: 1.35-7.85; p = 0.009), acute kidney injury (OR = 6.98; 95%CI: 2.32-20.96; p < 0.001), time to diuretic administration >60 minutes after ED arrival (OR = 3.89; 95%CI: 2.16-7.00; p < 0.001), and no discharge advice for follow-up (OR = 2.30; 95%CI: 1.10-4.77; p = 0.028). Conclusion: AHF patients who had good response to intravenous diuretics and were discharged from the ED were at high risk for 30-day adverse events. Ten factors predicted 30-day adverse events after discharge from the ED.