The initial rhythm is a known predictor of survival in extracorporeal cardiopulmonary resuscitation (ECPR) patients. However, the effect of the rhythm at hospital admission on outcomes in these patients is less clear.

This observational, single-center study assessed the influence of the rhythm at hospital admission on 30-day survival and neurological outcomes at discharge in patients who underwent ECPR for out-of-hospital cardiac arrest (OHCA).

Between January 2012 and December 2023, 1,219 OHCA patients were admitted, and 210 received ECPR. Of these, 196 patients were analyzed. The average age was 52.9 years (±13), with 80.6 % male. The median time to ECPR initiation was 61 min (IQR 54–72). Patients with ventricular fibrillation as both the initial and admission rhythm had the highest 30-day survival rate (52 %: 35/67), while those with asystole in both instances had the lowest (6 %: 1/17, log-rank p < 0.00001). After adjusting for age, sex, initial rhythm, resuscitation time, location, bystander, and witnessed status, asystole at admission was linked to higher 30-day mortality (OR 4.03, 95 % CI 1.49–12.38, p = 0.009) and worse neurological outcomes (Cerebral Performance Category 3–5) at discharge (OR 4.61, 95 % CI 1.49–17.62, p = 0.013).

The rhythm at hospital admission affects ECPR outcomes. Patients presenting with and maintaining ventricular fibrillation have a higher chance of favorable neurological survival, whereas those presenting with or converting to asystole have poor outcomes. The rhythm at hospital admission appears to be a valuable criterion for deciding on ECPR initiation.