Impact of Timing Parameters on Outcomes Following Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review and Meta-Analysis

Abstract

Background: Cardiac arrest remains a significant public health problem with high mortality. Extracorporeal cardiopulmonary resuscitation (ECPR) has emerged as a promising intervention for refractory cardiac arrest but, the impact of the critical time intervals on outcomes remains debated. This study investigates optimal timing thresholds and impact of critical time intervals to patients outcomes following ECPR.

Methods: A systematic review and meta-analysis was conducted per PRISMA guidelines, including 23 studies (n=3.196) published between 2015-2024. Evaluated time intervals included no-flow duration (NFD), low-flow duration (LFD), and time from cardiac arrest to ECMO initiation (CA-to-ECMO). Outcomes assessed included neurological status using the Cerebral Performance Category (CPC) scale, survival at discharge, and hospital stay duration.

Results: Patients with LFD <45 minutes showed significantly higher survival at discharge (32% vs. 23%, p = 0.034) and favorable neurological outcomes (26% vs. 20%, p = 0.046). Meta-regression demonstrated a strong inverse association between LFD and survival (p = 0.060; R² = 0.540) and a trend toward improved neurological outcomes (p = 0.055; R² = 0.643). Longer NFD was linked with poorer outcomes but without statistical significance. Arrest-to-ECMO time showed non-significant associations, with best results when <50 minutes. Subgroup analysis revealed stricter LFD thresholds correlated with improved outcomes for IHCA, while OHCA declined markedly when LFD exceeded 70 minutes.

Conclusions: LFD is strongly associated with outcomes in ECPR with best results occur when LFD is <45 minutes. Location-specific timing thresholds and rapid ECMO deployment may be essential to maximizing outcomes.

Keywords: Cardiac arrest; Cardiopulmonary resuscitation; Extracorporeal cardiopulmonary resuscitation; Outcomes; Time Intervals