Early left atrial venting versus conventional treatment for left ventricular decompression during venoarterial extracorporeal membrane oxygenation support: The EVOLVE‐ECMO randomized clinical trial

Aims Few studies have reported data on the optimal timing of left ventricular (LV) unloading during venoarterial extracorporeal membrane oxygenation (VA‐ECMO) for cardiac arrest or shock. This study evaluated the feasibility of an early LV unloading strategy compared with a conventional strategy in VA‐ECMO. Methods and results Between December 2018 and August 2022, 60 patients at two institutions were randomized in a 1:1 ratio to receive early (n = 30) or conventional (n = 30) LV unloading strategies. The early LV unloading strategy was defined as LV unloading performed at the time of VA‐ECMO insertion. LV unloading was performed using a percutaneous transseptal left atrial cannulation via the femoral vein incorporated into the ECMO venous circuit. The early and conventional LV unloading groups included 29 (96.7%) and 23 (76.7%) patients, respectively (median time from VA‐ECMO insertion to LV unloading: 48.4 h, interquartile range 47.8–96.5 h). The groups showed no significant differences in the rate of VA‐ECMO weaning as the primary endpoint (70.0% vs. 76.7%; relative risk 0.91; 95% confidence interval 0.67–1.24; p = 0.386) and survival to discharge (53.3% vs. 50.0%, p = 0.796). However, the pulmonary congestion score index at 48 h after LV unloading was significantly improved only in the early LV unloading group (2.0 ± 0.7 vs. 1.7 ± 0.6 at baseline vs. at 48 h; p = 0.008). Conclusions Compared with the conventional approach, early LV unloading did not improve the VA‐ECMO weaning rate, despite the rapid improvement in pulmonary congestion. Therefore, the results of this study do not support the application of this strategy after VA‐ECMO insertion. Patients with significant pulmonary oedema or aortic valve (AV) closure during venoarterial extracorporeal membrane oxygenation (VA‐ECMO) were randomized to early left ventricular (LV) unloading or conventional strategy groups (1:1). The primary endpoint was the rate of weaning from VA‐ECMO during index admission. The early LV unloading strategy did not increase the weaning rate from VA‐ECMO compared with the conventional approach. CV, cardiovascular; HT, heart transplantation; ICU, intensive care unit; LVAD, left ventricular assist device.