Extracorporeal cardiopulmonary resuscitation versus conventional cardiopulmonary resuscitation for patients with refractory out-of-hospital cardiac arrest: A retrospective propensity matching analysis.

ABSTRACT

OBJECTIVE: The incidence of out-of-hospital cardiac arrest (OHCA) is high. Though extracorporeal cardiopulmonary resuscitation (ECPR) has been considered a potential treatment for refractory cardiac arrest after failure of conventional cardiopulmonary resuscitation (CCPR), the benefit of ECPR in refractory OHCA remains uncertain. METHODS: In this retrospective cohort study, we included patients with refractory OHCA who visited the Emergency Department of the Aerospace Center Hospital between January 2018 and April 2023. We divided the patients into the ECPR Group and the CCPR Group. The primary endpoint of the study was the neurological function of the patients in both groups 3 months after the cardiac arrest. We used propensity score matching to reduce selection bias and identified factors associated with good neurological function when OHCA was treated with ECPR by performing univariate and multivariate correlation analyses on surviving patients with good neurological function in the ECPR group. RESULTS: During the study period, we enrolled 133 patients, consisting of 33 in the ECPR group and 100 in the CCPR group. The survival rate of patients with good neurological function at discharge was 18.2% (6/33 cases) in the ECPR group and 9% (9/100 cases) in the CCPR group, p = .20. Three months after discharge, the survival rate of patients with good neurological function was 15.2% (5/33 cases) in the ECPR group and 8% (8/100 cases) in the CCPR group, p = .31. Using propensity score matching, we identified 22 pairs of patients for further analysis. Among these, 3 months after discharge, the survival rate of patients with good neurological function was 13.6% (3/22 cases) in the ECPR group and 4.5% (1/22 cases) in the CCPR group, p = .61, and the survival rate at discharge was 18.2% (4/22 cases) in the ECPR group and 4.5% (1/22 cases) in the CCPR group, p = .34. The univariate analysis of patients with good neurological function in the ECPR group showed that time without perfusion, hypoperfusion time, and PCI treatment were associated factors affecting the prognosis of neurological function in patients, while multivariate analysis showed that hypoperfusion time was independently associated with good neurological function, with an OR (95% CI) of 1.06 (1.00-1.14) and p = .05. CONCLUSION: Our findings suggested that ECPR failed to significantly improve neurological outcome in patients with refractory OHCA; however, the small sample size in this study may be insufficient to detect clinically relevant differences. In addition, hypoperfusion time may be a key predictive factor in identifying candidates for ECPR.