Prognostic Value of Delirium in Patients With Acute Heart Failure in the Intensive Care Unit

Background: Delirium is a common adverse event observed in patients admitted to the intensive care unit (ICU). However, the prognostic value of delirium and its determinants have not been thoroughly investigated in patients with acute heart failure (AHF). Methods: We investigated 408 consecutive patients with AHF admitted to the ICU. Delirium was diagnosed by means of the Confusion Assessment Method for ICU tool and evaluated every 8 hours during the patients’ ICU stays. Results: Delirium occurred in 109 patients (26.7%), and the in-hospital mortality rate was significantly higher in patients with delirium (13.8% vs 2.3%; P < 0.001). Multivariate logistic regression analysis showed that delirium independently predicted in-hospital mortality (odds ratio [OR] 4.33, confidence interval [CI] 1.62-11.52; P = 0.003). Kaplan-Meier analysis showed that the 12-month mortality rate was significantly higher in patients with delirium compared with those without (log-rank test: P < 0.001), and Cox proportional hazards analysis showed that delirium remained an independent predictor of 12-month mortality (hazard ratio 2.19, 95% CI 1.49-3.25; P < 0.001). The incidence of delirium correlated with severity of heart failure as assessed by means of the Get With The Guidelines–Heart Failure risk score (chi-square test: P = 0.003). Age (OR 1.05, 95% CI 1.02-1.09; P = 0.003), nursing home residential status (OR 3.32, 95% CI 1.59-6.94; P = 0.001), and dementia (OR 5.32, 95% CI 2.83-10.00; P < 0.001) were independently associated with the development of delirium. Conclusions: Development of delirium during ICU stay is associated with short- and long-term mortality and is predicted by the severity of heart failure, nursing home residential, and dementia status.