Prognostic predictors in patients with cardiopulmonary arrest: A novel equation for evaluating the 30-day mortality

Background: Early prediction of outcomes after cardiopulmonary arrest (CPA) is important for considering the best support. Our purpose was to evaluate predictors of the 30-day mortality in patients with CPA after return of spontaneous circulation (ROSC) and to assess an equation for calculating the 30-day mortality using clinical parameters.Methods: We retrospectively analyzed the data of 194 consecutive patients with CPA and ROSC in a derivation study (2015-2022). We compared clinical parameters between the survived (n = 78) and dead (n = 116) pa-tients. We derived an equation for estimated probability of death based on clinical parameters, using multivariate logistic regression analysis. The reliability of the equation was validated in 80 additional patients with CPA.Results: The 30-day mortality was associated with sex, witnessed cardiac arrest, bystander cardiopulmonary re-suscitation (CPR), CPA due to acute myocardial infarction, pupil diameter, Glasgow Coma Scale score (GCS), pres-ence of light reflex, arterial or venous pH, lactate levels, initial ventricular fibrillation (VF), CPA time, and age. The derived logistic regression equation was as follows: Estimated probability of death = 1 / (1 + e-x), x = (0.25 x bystander CPR) + (0.44 x pupil diameter) - (0.14 x GCS) + (0.09 x lactate) - (1.87 x initial VF) + (0.07 x CPA time) + (0.05 x age) -7.03. The cut-off value for estimated probability of death calculated by this equation was 54.5 %, yielding a sensitivity, specificity, and accuracy of 86.2 %, 80.8 %, and 84.5 %, respectively. In the validation model, these values were 81.8 %, 85.7 %, and 82.5 %, respectively.Conclusions: The 30-day mortality may be calculated after ROSC in patients with CPA using simple clinical param-eters. This equation may facilitate further best support for patients with CPA.& COPY; 2023 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.