Development and Validation of a Clinical Score to Predict Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation

Abstract

IMPORTANCE Extracorporeal cardiopulmonary resuscitation (ECPR) is expected to improve the neurological outcomes of patients with refractory cardiac arrest; however, it is invasive, expensive, and requires substantial human resources. The ability to predict neurological outcomes would assist in patient selection for ECPR. OBJECTIVE To develop and validate a prediction model for neurological outcomes of patients with out-of-hospital cardiac arrest with shockable rhythm treated with ECPR. DESIGN, SETTING, AND PARTICIPANTS This prognostic study analyzed data from the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry, a multi-institutional nationwide cohort study that included 87 emergency departments in Japan. All adult patients with out-of-hospital cardiac arrest and shockable rhythm who were treated with ECPR between June 2014 and December 2017 were included. Patients were randomly assigned to the development and validation cohorts based on the institutions. The analysis was conducted between November 2019 and August 2020. EXPOSURES Age (<65 years), time from call to hospital arrival (Յ25 minutes), initial cardiac rhythm on hospital arrival (shockable), and initial pH value (Ն7.0). MAIN OUTCOMES AND MEASURES The primary outcome was 1-month survival with favorable neurological outcome, defined by Cerebral Performance Category 1 or 2. In the development cohort, a simple scoring system was developed to predict this outcome using a logistic regression model. The diagnostic ability and calibration of the scoring system were assessed in the validation cohort. RESULTS A total of 916 patients were included, 458 in the development cohort (median [interquartile range {IQR}] age, 61 [47-69] years, 377 [82.3%] men) and 458 in the validation cohort (median [IQR] age, 60 [49-68] years; 393 [85.8%] men). The cohorts had the same proportion of favorable neurological outcome (57 patients [12.4%]). The prediction scoring system was developed, attributing a score of 1 for each clinical predictor. Patients were divided into 4 groups, corresponding to their scores on the prediction model, as follows: very low probability (score 0), low probability (score 1), middle probability (score 2), and high probability (score 3-4) of good neurological outcome. The mean predicted probabilities in the groups stratified by score were as follows: very low, 1.6% (95% CI, 1.6%-1.6%); low, 4.4% (95% CI, 4.2%-4.6%); middle, 12.5% (95% CI, 12.1%-12.8%); and high, 30.8% (95% CI, 29.1%-32.5%). In the validation cohort, the C statistic of the scoring system was (continued) Key Points Question Can the neurological outcome of patients with out-ofhospital cardiac arrest and shockable rhythm who are treated with extracorporeal cardiopulmonary resuscitation (ECPR) be predicted using accessible information? Findings In this prognostic study of 916 patients, a model using time to hospital arrival, pH in initial blood gas assessment, shockable rhythm on hospital arrival, and being younger than 65 years was developed to predict survival ...

Extracorporeal cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest: a retrospective large cohort multicenter study in Japan

“…First, to the best of our knowledge, this study includes the largest cohort of patients with OHCA who received ECPR. Although several large cohort studies of (> 200) patients with OHCA who received ECPR have been reported in France [ 4 ], four other European countries [ 3 ], Korea [ 5 ], and Japan [ 6 , 7 , 9 ], this study included 1.5 times as much participants as the previous study with the largest number (916) of patients [ 6 ] and about half the number of patients in a recently published systematic review of ECPR for OHCA [ 26 ]. Second, unlike one previous study that included only patients with shockable rhythm [ 6 ], this study included patients with all types of cardiac rhythm.…”

“…In previous studies that used detailed clinical data of more than 100 patients with OHCA who received ECPR, the proportion of favorable neurological outcome at discharge was 6–39% [ 3 – 6 , 8 , 9 , 12 – 14 , 17 , 27 , 28 ]. This study included different types of patients, and favorable neurological outcome was observed in 16.7% and 9.2% of patients who had shockable rhythm and PEA, respectively.…”

A clinical score to predict mortality in patients after acute heart failure from Japanese registry

“…Calibration plots were created to graphically indicate the association between the predicted and observed outcomes using locally weighted scatterplot smoothing. 21 We used a bootstrapping procedure (200 samples drawn with replacement from the original sample) to assess the internal validation of the model.…”

“…The performance of the model was evaluated based on the C index, Nagelkerke's R 2 value, calibration intercept and slope, and Brier's score using the ‘rms’ package. Calibration plots were created to graphically indicate the association between the predicted and observed outcomes using locally weighted scatterplot smoothing 21 . We used a bootstrapping procedure (200 samples drawn with replacement from the original sample) to assess the internal validation of the model.…”

Derivation and validation of the CANP scoring model for predicting the neurological outcome in post-cardiac arrest patients

“…However, none of these indicators can by itself satisfactorily distinguish patients with favorable outcomes from individuals with unfavorable ones, showing that it might be necessary to establish a "proper scale" on the basis of combined predictive factors. 16,17 In the CA literature, there are a large number of singleand multicenter reports in which so-called independent factors have been identified as related to different outcomes. 4,[18][19] More rigorous studies have identified factors by multivariate analyses that use sophisticated equations and scoring systems able to predict prognosis into consideration.…”