Validation of a decision support tool for the evaluation of cardiac arrest victims.

BACKGROUND: There is currently no well-accepted model for early and accurate prediction of neurologic and vital outcomes after cardiac arrest. Recent studies indicate that individuals with acute myocardial ischemia as the etiology for the arrest may benefit from early revascularization.

HYPOTHESIS: This study was undertaken to examine whether the cardiac arrest score is valid for predicting outcomes upon arrival at the emergency department.

METHODS: We previously developed a cardiac arrest score based on time to return of spontaneous circulation, initial systolic blood pressure, and level of neurologic alertness in 127 patients (derivation set). This score was prospectively applied to 62 patients with similar clinical profiles (validation set). Utility of the score was evaluated by the area under the receiver operator characteristic curves (C) for both sets. Consistency was measured by using the alpha statistic applied to the cumulative survival at each ascending level of the score.

RESULTS: The derivation and validation sets were similar with respect to baseline characteristics and proportions at each level of score. The survival to discharge was 41.7 and 53.2% for the two sets, respectively. The value of C was 0.89 +/- 0.03 and 0.93 +/- 0.03 for neurologic recovery and 0.81 +/- 0.04 and 0.92 +/- 0.04 for survival to discharge in the two sets, respectively. The level of agreement between the sets across the levels of the score was 0.98 and 0.99 (both p < 0.0001) for the two outcomes.

CONCLUSIONS: The cardiac arrest score is a valid decision support tool in the evaluation of cardiac arrest victims. Patients with the most favorable scores may be considered for early angiography and revascularization if myocardial ischemia is the etiology of the arrest.