External validation of the BE-ALIVE score for predicting 30-day mortality in patients presenting with acute coronary syndromes

Introduction: The BE-ALIVE score is an additive scoring system for estimating 30-day mortality in patients presenting with an acute coronary syndrome (ACS) [1]. However, it had only previously been tested on an internal validation cohort. The aim was to assess the scoring system on an external validation cohort. Methods: The scoring system comprises six domains: (1) Base Excess (1 point for < -2 mmols/L), (2) Age (<65 years: 0 points, 65-74: 1 point, 75-84: 2 points, > 85: 3 points), (3) Lactate (<2 mmols/L: 0 points, 2-4.9: 1 point, 5-9.9: 3 points, > 10: 6 points), (4) Intubated & Ventilated (2 points), (5) Left Ventricular function (normal or mildly impaired: -1 point, moderately impaired: 1 point, severely impaired: 3 points) and (6) External / out of hospital cardiac arrest (1 point). We applied the BE-ALIVE score was applied to 205 consecutive patients at a different institution. Results: Calibration was strong, with an observed to expected ratio of 1.01, a calibration slope of 1.26 and calibration in the large of -0.03. The Spiegelhalter's Z-statistic was -0.95 (p = 0.34). The AUC was 0.95 (0.92-0.98) in the external validation cohort versus 0.90 (0.85-0.95) during internal validation. Overall performance was excellent with a Brier score of 0.07 versus 0.06 during internal validation. The negative predictive value for 30-day mortality of a BE-ALIVE score < 4 was 98 %, with a positive predicted value of a score > 10 of 95 %. Conclusions: The BE-ALIVE score remains a robust predictor of 30-day mortality in an external validation cohort.