Refractory out‐of‐hospital cardiac arrest and extracorporeal cardiopulmonary resuscitation: A meta‐analysis of randomized trials

• Published in: Artificial organs Vol. 47; no. 5; pp. 806 - 816
• Main Authors: Scquizzato, Tommaso, Bonaccorso, Alessandra, Swol, Justyna, Gamberini, Lorenzo, Scandroglio, Anna Mara, Landoni, Giovanni, Zangrillo, Alberto
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-05-2023
• Subjects: Adult; Adults; Cardiac arrest; Cardiopulmonary Resuscitation; Clinical trials; CPR; ECMO; extracorporeal cardiopulmonary resuscitation; extracorporeal membrane oxygenation; Heart; Humans; Lifesaving; Meta-analysis; Out-of-Hospital Cardiac Arrest - therapy; out‐of‐hospital cardiac arrest; Patient Discharge; Perfusion; Randomized Controlled Trials as Topic; Resuscitation; Survival; ECMO; extracorporeal cardiopulmonary resuscitation; extracorporeal membrane oxygenation; out-of-hospital cardiac arrest
• ISSN: 0160-564X; 1525-1594
• DOI: 10.1111/aor.14516

Background
In adults with refractory out‐of‐hospital cardiac arrest, when conventional cardiopulmonary resuscitation (CPR) alone does not achieve return of spontaneous circulation, extracorporeal CPR is attempted to restore perfusion and improve outcomes. Considering the contrasting findings of recent studies, we conducted a meta‐analysis of randomized controlled trials to ascertain the effect of extracorporeal CPR on survival and neurological outcome.
Methods
Pubmed via MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched up to February 3, 2023, for randomized controlled trials comparing extracorporeal CPR versus conventional CPR in adults with refractory out‐of‐hospital cardiac arrest. Survival with a favorable neurological outcome at the longest follow‐up available was the primary outcome.
Results
Among four randomized controlled trials included, extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome at the longest follow‐up available for all rhythms (59/220 [27%] vs. 39/213 [18%]; OR = 1.72; 95% CI, 1.09–2.70; p = 0.02; I2 = 26%; number needed to treat of 9), for initial shockable rhythms only (55/164 [34%] vs. 38/165 [23%]; OR = 1.90; 95% CI, 1.16–3.13; p = 0.01; I2 = 23%; number needed to treat of 7), and at hospital discharge or 30 days (55/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13–2.92; p = 0.01; I2 = 0.0%). Overall survival at the longest follow‐up available was similar (61/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13–2.92; p = 0.59; I2 = 58%).
Conclusions
Extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome in adults with refractory out‐of‐hospital cardiac arrest, especially when the initial rhythm was shockable.
Review Registration
PROSPERO CRD42023396482.
In this meta‐analysis of randomized trials, survival with a favorable neurological outcome at the longest follow‐up available was higher in patients randomized to receive extracorporeal cardiopulmonary resuscitation compared to conventional cardiopulmonary resuscitation. The highest benefit was observed in patients with an initial shockable rhythm. Nine patients with all‐rhythm refractory out‐of‐hospital cardiac arrest or seven with an initial shockable rhythm should be treated with extracorporeal cardiopulmonary resuscitation to achieve one additional survivor with a favorable neurological outcome.