Written by Clay Smith
Early extracorporeal cardiopulmonary resuscitation (ECPR, aka ECMO) was not superior to standard advanced cardiac life support (ACLS) for 180-day survival with good neurological outcome, but there may be a silver lining.
Why does this matter?
Out of hospital cardiac arrest (OHCA) outcomes are bleak. ECPR is a promising approach to improve this (see ARREST RCT), but does it improve what really matters – sustained survival with good neurological outcome?
Early ECPR vs usual ACLS
This was a single-center RCT, based in Prague, with 256 (of a planned 285 – study stopped due to futility) adult patients with OHCA. Patients all had witnessed OHCA with no ROSC after 5 minutes of ACLS. About half had mechanical compression and rapid transport for early invasive ECPR, while the other half had standard ACLS on site. There was no significant difference in the primary outcome of 180-day good neurological outcome: ECPR with 39 patients (31.5%) and standard ACLS 29 (22.0%) had good neurologic outcome at 180 days with (OR 1.63, 95%CI 0.93 to 2.85); difference 9.5% (95%CI -1.3% to 20.1%); P = .09). Interestingly, a secondary outcome of 30-day good neurological outcome was significantly better: ECPR 38 patients (30.6%) and ACLS 24 (18.2%); (OR 1.99 (95%CI 1.11 to 3.57); difference 12.4% (95%CI 1.9% to 22.7%), P = .02). More in the ECPR group had initial asystole (25%) vs the ACLS group (18%), but more in the ECPR group had targeted temperature management than ACLS, 95% vs 70%, respectively. Bleeding complications were more common in the ECPR group vs ACLS: 31% vs 15%, respectively. More patients in the ECPR group were evaluated and accepted for organ donation than the ACLS group. Ten patients crossed over from the ACLS group to the ECPR group, and 4 out of 10 met the primary outcome. But the study was intention to treat. What I take home is that an early ECPR strategy is promising, and I agree, the study may have been underpowered to detect a difference. Median age was 58 in the entire cohort, and many patients had significant comorbidity. So, though there was an early signal of better 30-day outcome, this faded by 180-days. I wonder how this would have looked in a younger patient population with fewer comorbid conditions.
Effect of Intra-arrest Transport, Extracorporeal Cardiopulmonary Resuscitation, and Immediate Invasive Assessment and Treatment on Functional Neurologic Outcome in Refractory Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA. 2022 Feb 22;327(8):737-747. doi: 10.1001/jama.2022.1025.