Extracorporeal life support in cardiac arrest: a post hoc Bayesian re-analysis of the INCEPTION trial

BACKGROUND: Previously, we performed the multicenter INCEPTION-trial, randomizing patients with refractory out-of-hospital cardiac arrest to extracorporeal CPR (ECPR) or conventional CPR (CCPR). Frequentist analysis showed no statistically significant treatment effect for the primary outcome; 30-day survival with favorable neurologic outcome (Cerebral Performance Category score 1-2). To facilitate a probabilistic interpretation of the results, we present a Bayesian re-analysis of the INCEPTION-trial. METHODS: We analyzed survival with favorable neurologic outcome at 30 days and 6 months under a minimally informative prior in the intention-to-treat population. Effect sizes are presented as absolute risk differences (ARD) and relative risks (RR), with 95% credible intervals (CrI). We estimated posterior probabilities at various thresholds, including the minimal clinically important difference (5% ARD), based on expert consensus, and performed sensitivity analyses under a skeptical and literature-based priors. RESULTS: The mean ARD for 30-day survival with favorable neurologic outcome was 3.6% (95% CrI -9.5-16.7%), favoring ECPR, with a median RR of 1.22 (95% CrI 0.59-2.51). The posterior probability of a minimal clinically important difference was 42% at 30 days and 42% at 6 months, in favor of ECPR. The probability of any harm at 30 days was 29% and 35% under a minimally-informative and skeptical prior, and <6% under both informative priors. CONCLUSION: Bayesian re-analysis of the INCEPTION-trial estimated a 42% probability of a minimal clinically important difference between ECPR and CCPR in refractory OHCA in terms of 30-day survival with favorable neurologic outcome. TRIAL REGISTRATION: Clinicaltrials.gov (NCT03101787, registered April 5th 2017).