Abstract 239: Out-of-Hospital Cardiac Arrest Survival Predicted at 24 Hours: The Application and Validation of a Novel Clinical Score
Background: Despite 50 years of research, survival prognostication is still dependant on clinical status at 72 hours. We developed and tested the accuracy of a 24 hour, novel clinical score to predict the probability of survival post non-traumatic cardiac arrest.
Methods: In 170 cardiac arrest survivors admitted between 2004-2010, a predictive model was developed. Variables used in univariate analyses to generate the prediction equation were: Initial Rhythm VF/VT, Return of Spontaneous Circulation (ROSC) ≤20 minutes, Brian Reflex Score (BRS)≥ 3 at 24 hours, Bystander CPR, and use of ≥3 doses of epinephrine. Multivariate logistic regression then retained significant predictors in a 50% random training sample, 84 patients (pts) and tested these in the remaining 50% validation sample, 86 pts. The diagnostic efficiency of the model was assessed using ROC analysis.
Results: Of 170 pts studied, mean age was 63 years(SD±15.7), 37 pts (21.7%) survived to discharge. The initial rhythm was VF/VT in 38 (22%), 58 (34%) had ROSC≤ 20 minutes, 34 (20%) had a BRS ≥3 at 24 hours, and 80(47%) received Hypothermia. Mean length of stay was 5.8 days (SD±7.8).The final model retained three predictors: VF/VT, ROSC≤ 20 minutes and BRS≥ 3 at 24 hours. Table below presents the probability of survival with presence/ absence of all combinations of these 3 predictors.
No single variable was robust in identifying the probability of survival (9%-17%). The presence of any 2 variables increases the probability to (55%-71%),however the presence of all 3 variables, in any patient increases the probability to 95%. The area under the ROC curve was 0.87 in the training sample and 0.84 in the validation sample.
Conclusion: This study demonstrates that a score comprising 3 easily clinically, accessible variables correctly identifies survival following cardiac arrest. This score,like many other clinical scores, is incremental in predictive accuracy and warrant revalidation in larger cohort.
- © 2012 by American Heart Association, Inc.