Using Base Excess, Albumin, Lactate, and Renal Function to Predict 30-Day Mortality in Patients Requiring Impella Monotherapy for Left-Sided Mechanical Circulatory Support: The BALLAR Score.

OBJECTIVES

To create a simple scoring system that can estimate 30-day mortality in patients requiring left-sided Impella implantation as standalone mechanical circulatory support (MCS).

METHODS

We retrospectively analysed 79 consecutive patients who required left-sided Impella MCS monotherapy. Regression analysis was used to elucidate significant associations between biochemical markers before Impella implantation and all-cause mortality at 30 days. Using these factors, a simple additive scoring system was created using a previously validated approach.

RESULTS

The BALLAR scoring system was created. Patients are assigned points based upon biochemical markers. These are summed and the final points tally provides an estimate of 30-day mortality. The points are assigned as follows: Lactate (mmol/l): ≤1.9: 0 points, 2-4.9: 1 Point, ≥5: 4 Points Creatinine Clearance (ml/min): ≤29.9: 6 points, 30-59.9: 4 points, 60-89.9: 1 point, ≥90: 0 points Serum Albumin (mmol/l): <25: 6 points, 25-34.9: 3 points, ≥35: 0 points Base Excess (mmol/L): < -2: 2 points, ≥-2: 0 points The total score can be used to estimate the probability of death at 30 days. A score less than 6 predicts a 30-day mortality of under 5%, whereas a score over 11 predicts a greater than 95% chance of death within 30 days.

CONCLUSION

Using this simple heuristic predicted 89% of 30-day deaths in our cohort. All the misclassifications were in the intermediate probability range (scores 5-11). This simple scoring system gives an effective estimate of the probability of death at 30 days in our cohort of patients.