Characterization of Hemodynamically Stable Acute Heart Failure Patients requiring Critical Care Unit Admissions

Abstract

Background: It remains unclear which patients with acute heart failure (AHF) may benefit from critical care unit (CCU) versus regular ward-based care when they are admitted to hospital. The purpose of this study was to evaluate the clinical predictors of adverse clinical outcomes and the need for CCU specific therapies in patients with AHF. Methods and Results: Using data from the ASCEND-HF trial, patients with AHF who did not require critical care related therapies within the preceding 12 hours of randomization were selected. The primary outcome was an in-hospital composite of the requirement of CCU specific therapies, and adverse clinical events (death, myocardial infarction, cardiogenic shock, resuscitated sudden cardiac death, or ventricular arrhythmias requiring intervention). A logistic regression model was developed to identify predictive variables; model discrimination and calibration were evaluated using the c-index and the Hosmer-Lemeshow tests, respectively. The study cohort included 4767 patients and the primary composite outcome occurred in 545 (11.4%) patients including 713 (15.4%) CCU specific therapies and 176 (3.7%) adverse clinical events. A total of 7 variables were predictors of the primary composite outcome: body mass index, chronic respiratory disease, respiratory rate, resting dyspnea, hemoglobin, sodium, and blood urea nitrogen. The simplified clinical prediction model demonstrated modest discrimination (c-index= 0.633) and good calibration (Hosmer-Lemeshow p=0.823). Conclusions: In a large, international trial of AHF, we identified clinical variables that identify patients who are likely to need a CCU. These findings may provide a more efficient means of triaging patients with AHF.