Prediction of Heart Failure Mortality in Emergent Care

BACKGROUND: Heart failure contributes to millions of emergency department (ED) visits, but hospitalization-versus-discharge decisions are often not accompanied by prognostic risk quantification. OBJECTIVE: To derive and validate a model for acute heart failure mortality applicable in the ED. DESIGN: Clinical data abstraction with development of a broadly applicable multivariate risk index for 7-day death using initial vital signs, clinical and presentation features, and readily available laboratory tests. SETTING: Multicenter study of 86 hospitals in Ontario, Canada. PATIENTS: Population-based random sample of 12 591 patients presenting to the ED from 2004 to 2007. MEASUREMENTS: Death within 7 days of presentation. RESULTS: In the derivation cohort (n = 7433; mean age, 75.4 years SD, 11.4; 51.5% men), mortality risk increased with higher triage heart rate (adjusted odds ratio OR, 1.15 95% CI, 1.03 to 1.30 per 10 beats/min) and creatinine concentration (OR, 1.35 CI, 1.14 to 1.60 per 1 mg/dL 88.4 µmol/L), and lower triage systolic blood pressure (OR, 1.52 CI, 1.31 to 1.77 per 20 mm Hg) and initial oxygen saturation (OR, 1.16 CI, 1.01 to 1.33 per 5%). Nonnormal serum troponin levels (OR, 2.75 CI, 1.86 to 4.07) were associated with increased mortality risk. Areas under the receiver-operating characteristic curves of the multivariate model were 0.805 for the derivation data set (bootstrap-corrected, 0.811) and 0.826 for validation data set (n = 5158; mean age, 75.7 years SD, 11.4; 51.6% men). In the derivation cohort, a multivariate index score stratified 7-day mortality with rates of 0.3%, 0.3%, 0.7%, and 1.9% in quintiles 1 to 4, respectively. Mortality rates in the 2 highest risk groups were 3.5% and 8.2% in deciles 9 and 10, respectively. LIMITATION: Left ventricular ejection fraction was not included in the model. CONCLUSION: A multivariate index comprising routinely collected variables stratified mortality risk with high discrimination in a broad group of patients with acute heart failure presenting to the ED. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research.