Abstract 17032: Novel risk score to predict in-hospital mortality in a contemporary Cardiac Intensive Care Unit
Introduction: Several validated risk models estimate probability of hospital mortality among patients admitted to general medical and surgical intensive care units (ICU). However, patients with critical illness from cardiac disease have generally been excluded from these models. We sought to develop a simple risk model specific for cardiac patients admitted to a specialized cardiac ICU (CICU).
Methods: Comprehensive clinical data was prospectively collected from consecutive patients admitted to a large tertiary-care CICU from 2007 to 2012. Patients were randomly assigned to derivation and validation cohorts in a 2:1 ratio. Lasso regression with bootstrap technique was used on the derivation cohort to construct the best prediction model of hospital death. Variables selected more than 80% of the time were used to create the new risk score, which was then applied to the validation cohort. The c-statistic was used to determine model performance, and was compared to that of the widely accepted, more complex Mortality Prediction Model (MPM0).
Results: 6433 patients were admitted to the CICU, of whom 5710 had a primary cardiac diagnosis. Complete data was available in 4641 patients, who comprise the study population. Primary diagnoses were: acute coronary syndrome (54%), arrhythmia (13%), valvular (12%), cardiomyopathy (8%) cardiac arrest (4%) and other (9%). Mean age was 65.5±21.9 years and ejection fraction was 43.8±16.7%. Overall hospital mortality was 10.4%. Table 1 shows the 8 variables included in the final model. The c-statistic was 0.83 for the validation cohort and 0.86 for the derivation cohort, indicating excellent discrimination. In the entire cohort, the simple CICU risk score demonstrated superior performance to the MPM0 model (c-statistic 0.85 vs. 0.82, p=0.036).
Conclusions: When applied to cardiac patients admitted to the CICU, a simplified 8-variable risk score predicts mortality better than a complex risk score developed for general ICU patients.
Author Disclosures: M.E. Rodrigo: None. F.M. Asch: None. T. Kumar: None. T.A. Singh: None. D.A. Morrow: None. F. Chang: None. R. Torguson: None. J.A. Panza: None. H.A. Cooper: None.
- © 2014 by American Heart Association, Inc.