Characterization of hemodynamically stable acute heart failure patients requiring a critical care unit admission: Derivation, validation, and refinement of a risk score.

BACKGROUND: Most patients with acute heart failure (AHF) admitted to critical care units (CCUs) are low acuity and do not require CCU-specific therapies, suggesting that they could be managed in a lower-cost ward environment. This study identified the predictors of clinical events and the need for CCU-specific therapies in patients with AHF. METHODS: Model derivation was performed using data from patients in the ASCEND-HF trial cohort (n=7,141), and the Acute Heart Failure Emergency Management community-based registry (n=666) was used to externally validate the model and to test the incremental prognostic utility of 4 variables (heart failure etiology, troponin, B-type natriuretic peptide [BNP], ejection fraction) using net reclassification index and integrated discrimination improvement. The primary outcome was an in-hospital composite of the requirement for CCU-specific therapies or clinical events. RESULTS: The primary composite outcome occurred in 545 (11.4%) derivation cohort participants (n=4,767) and 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 (c index=0.633, Hosmer-Lemeshow P=.823). In the validation cohort (n=666), 87 (13.1%) events occurred (c index=0.629, Hosmer-Lemeshow P=.386) and adding ischemic heart failure, troponin, and B-type natriuretic peptide improved model performance (net reclassification index 0.79, 95% CI 0.046-0.512; integrated discrimination improvement 0.014, 95% CI 0.005-0.0238). The final 10-variable clinical prediction model demonstrated modest discrimination (c index=0.702) and good calibration (Hosmer-Lemeshow P=.547). CONCLUSIONS: We derived, validated, and improved upon a clinical prediction model in an international trial and a community-based cohort of AHF. The model has modest discrimination; however, these findings deserve further exploration because they may provide a more accurate means of triaging level of care for patients with AHF who need admission.

Duke Scholars

Author Adrian Felipe Hernandez Medicine, Cardiology

Author Christopher Michael O'Connor Medicine, Clinical Pharmacology

Author Paul Wayne Armstrong Medicine, Cardiology