Assessment of a University of California, Los Angeles 4-variable risk score for advanced heart failure.
Bottom Line: The model-predicted survival was compared to Kaplan-Meier's estimated survival at 1, 2, and 3 years.Fairly similar results were found when the analyses were repeated in 715 patients after multivariate imputation of missing data.The UCLA 4-variable risk model calibration was inconsistent and high-risk discrimination was poor in an external validation cohort.
Affiliation: Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden (U.S.) Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden (U.S.).Show MeSH
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Mentions: Clinical characteristics of the study population are shown in the 1. Overall, baseline characteristics in our study population were similar to the original UCLA cohort. During a mean follow‐up of 2.1 years, 37 (21%) events occurred. Overall, event‐free survival (EFS) was 88% at 1 year, 81% at 2 years, and 75% at 3 years. In Kaplan‐Meier's EFS analysis, there was lack of discrimination between the 2 highest risk groups (P=0.692) (Figure 1). Cox's model, with the risk score as a continuous independent variable, had better discrimination (C‐index, 0.781), compared to the risk group Cox model (C‐index, 0.757). The time‐dependent ROC curve analyses demonstrated good overall discrimination; AUCs at 1, 2, and 3 years, by continuous risk score: 0.801 (95% CI, 0.722 to 0.891), 0.774 (95% CI, 0.691 to 0.857), and 0.837 (95% CI, 0.751 to 0.922), respectively; by risk groups: 0.776 (95% CI, 0.676 to 0.876), 0.748 (95% CI, 0.658 to 0.837), and 0.798 (95% CI, 0.709 to 0.887), respectively. The overall observed/predicted ratios were 0.97, 0.96, and 0.97, respectively. The observed and predicted EFS in the 4 risk groups are shown in Figure 2. The difference between observed and predicted survival ranged from −14 to +17 percentage points.
Affiliation: Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden (U.S.) Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden (U.S.).