Extracorporeal Life-support for Out-of-hospital Cardiac Arrest: A Nationwide Multicenter Study.

Background: Despite potential clinical roles of extracorporeal life support (ECLS) for out-of-hospital cardiac arrest (OHCA) compared to that of conventional cardiopulmonary resuscitation (CCPR), use of ECLS for OHCA is not strongly endorsed by current clinical guidelines.

Objective: The purpose of this study is to investigate the clinical roles of extracorporeal life support (ECLS) compared with that of conventional cardiopulmonary resuscitation (CCPR) for out-of-hospital cardiac arrest (OHCA) patients.

Methods: The outcomes of OHCA between 2015 and 2020, enrolled in the Korean Cardiac Arrest Research Consortium (KoCARC), a multicenter OHCA patient registry including 65 participating hospitals throughout the Republic of Korea (ClinicalTrials.gov, number NCT03222999). Differences in clinical features were adjusted by matching the propensity for ECLS. The primary outcome was 30-day neurologically favorable survival with cerebral performance category of 1 or 2. Restricted mean survival time (RMST) was used to compare outcomes between groups.

Results: Of 12,006 patients included, ECLS was applied to 272 patients (2.2%). The frequency of neurologically favorable survival was higher in the ECLS group than the CCPR group (RMST difference, 5.5 days [95% CI, 4.1-7.0 days], P < 0.001). In propensity score-matched 271 pairs, the clinical outcome of ECLS and CCPR did not differ to a statistically significant extent (RMST difference, 0.4 days [95% CI -1.6 to 2.5 days], P = 0.67). Subgroup analyses revealed that the clinical roles of ECLS was evident in patients with nonshockable rhythm or CPR time ≥20 min (RMST difference, 2.7 days [95% CI 0.5-4.8 days], P = 0.015), but not in patients without these features (RMST difference, -3.7 days [95% CI -7.6 to 0.2 days], P = 0.07).

Conclusions: In this real-world data analysis, ECLS compared to CCPR did not result in better overall clinical outcomes of OHCA. The clinical efficacy of ECLS may be limited to a subgroup of high-risk patients.