Analysis Of Risk Factors For In-hospital Death In Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation After Cardiac Arres

Background:Previous studies found an increasing trend of extracorporeal cardiopulmonary resuscitation(ECPR)use in patients with cardiac arrest(CA).Although the use of ECPR reduced mortality in patients with CA compared with those receiving conventional cardiopulmonary resuscitation(CCPR),the mortality remains high.This study was designed to identify the potential mortality risk factors for patients receiving ECPR after CA,to optimize ECPR management and improve patients’outcomes.Methods:We conducted a prospective,multicentre study collecting 990 CA patients undergoing ECPR in 61 hospitals in China from January 2017 to May 2022.The population was divided into two cohorts according to the date of admission,one cohort was used to build prediction model as training data set while the other cohort was used for external validation as validation data set.Variables of the training set were screened by backwards stepwise based on Akaike information criterion,and the prediction model of in-hospital mortality risk of ECPR patients was constructed by Cox multivariate regression,followed by forest plot and nomogram.The ability of the prediction model was described by calibration and discrimination,and Boostrap resampling was applied in order to obtain internal validation from training set and external validation from validation cohort.Results:1.Of the 990 CA patients treated with ECPR,a total of 351 patients meeting the inclusion criteria was included as development cohort and 68 patients were included in the validation cohort;Of 351 patients in the development cohort,227(64.8%)died in hospital.2.Univariate analysis showed that pre-arrest rhythm,smoking history,cirrhosis history,nervous system complications,limb complications,pH,HCO3-,Lactate acid,Lac,continuous renal replacement therapy(CRRT)differ significantly between the survivors and non-survivors(p<0.05).3.Cox multivariate analysis showed that cerebrovascular history,unshockable arrhythmia(pulseless electrical activity/asystole),higher levels of lactic acid(Lac),45-60 years old,higher pH,and IABP were significantly correlated with prognosis of ECPR patients.Internal validation by bootstrap resampling was subsequently used to evaluate the stability of the model,showing moderate discrimination,especially in the early stage following ECPR,with a C statistic of 0.70 and adequate calibration with GOF chi-square=10.4(p=0.50)for the entire cohort.Fair discrimination with c statistic of 0.65 and good calibration(GOF chi-square=6.1,p=0.809)in the external validation cohort demonstrating the model’s ability to predict in-hospital death across a wide range of probabilities.Conclusion:Among patients receiving ECPR for CA,having a history of cerebrovascular diseases,a higher value in Lac,initial unshockable rhythms were identified as independent risk factors,while aged 45-60 years old,having a higher value in pH,receiving IABP were protective factors against in-hospital mortality.These factors can be used for risk prediction,thereby improving the selection and management of patients for this resource-intensive therapy.