A scale with 3 factors including a history of heart failure, NYHA IV at discharge, and atrial fibrillation on electrocardiogram which has an area under the receiver operating characteristic curve (AUC) is 0.7174 (95% confidence interval, 0.598 - 0.818) and a cut-point ≥1 has the sensitivity 70.27% and the specificity 62.96%.