Prognostic value and risk factors of delirium in emergency patients with decompensated heart failure

Objective: Patients with heart failure (HF) seen at the emergency department (ED) are increasingly older and more likely to present delirium. Little is known, however, about the impact of this syndrome on outcome in these patients. We aimed to investigate the prognostic value and risk factors of delirium at admission (prevalent delirium) in ED patients with decompensated HF.

Methods and results: We performed a prospective, observational study, analyzing the presence of prevalent delirium in decompensated HF patients attended at the ED in 2 hospitals in Spain in the context of the Epidemiology Acute Heart Failure Emergency project. We used the brief Confusion Assessment Method to assess the presence of delirium. Patients were followed for 1 month after discharge. Of 239 enrolled patients (81.7 ± 9.4 years, women 61.1%, long-term care [LTC] 11%), 35 (14.6%) had prevalent delirium (20% LTC vs 9.4% in-home, P = .078). The factors associated with delirium in the multivariate analysis were functional dependence (P = .001) and dementia (P = .005). Prevalent delirium was an independent risk factor of death within 30 days (OR 3.532; 95% CI 1.422-8.769, P = .007) whereas autonomy in basic activities of daily living was a protective factor (OR 0.971; 95% CI 0.956-0.986, P = .001). The area under the ROC curve for our 30-day mortality model was 0.802 (95% CI 0.721-0.883, P = .001).

Conclusion: Prevalent delirium in patients with decompensated HF was a predictor of short-term mortality. Routine identification of delirium in patients at risk, particularly those with greater functional dependence, can help emergency physicians in decision-making and enhance care in patients with decompensated HF.