Risk Stratification for In-Hospital Mortality in Acutely Decompensated Heart Failure: Classification and Regression Tree Analysis

CONTEXT Estimation of mortality risk in patients hospitalized with acute decompensated heart failure (ADHF) may help clinicians guide care. OBJECTIVE To develop a practical user-friendly bedside tool for risk stratification for patients hospitalized with ADHF. DESIGN, SETTING, AND PATIENTS The Acute Decompensated Heart Failure National Registry (ADHERE) of patients hospitalized with a primary diagnosis of ADHF in 263 hospitals in the United States was queried with analysis of patient data to develop a risk stratification model. The first 33 046 hospitalizations (derivation cohort; October 2001-February 2003) were analyzed to develop the model and then the validity of the model was prospectively tested using data from 32 229 subsequent hospitalizations (validation cohort; March-July 2003). Patients had a mean age of 72.5 years and 52% were female. MAIN OUTCOME MEASURE Variables predicting mortality in ADHF. RESULTS When the derivation and validation cohorts are combined, 37 772 (58%) of 65 275 patient-records had coronary artery disease. Of a combined cohort consisting of 52 164 patient-records, 23 910 (46%) had preserved left ventricular systolic function. In-hospital mortality was similar in the derivation (4.2%) and validation (4.0%) cohorts. Recursive partitioning of the derivation cohort for 39 variables indicated that the best single predictor for mortality was high admission levels of blood urea nitrogen (≥43 mg/dL [15.35 mmol/L]) followed by low admission systolic blood pressure (