October 9, 2020
Study Evaluates LV Unloading in Cardiogenic Shock Patients Treated With VA-ECMO
October 9, 2020—Online ahead of print in Circulation, Benedikt Schrage, MD, et al reported findings from an international, multicenter cohort study on the use of left ventricular (LV) unloading in patients with cardiogenic shock (CS) treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO), ultimately concluding that LV unloading was associated with lower mortality.
The study investigators explained that VA-ECMO has been increasingly used over the last few decades to treat CS; however, its effect on mortality is still being discussed. Additionally, VA-ECMO increases LV pressure due to retrograde aortic perfusion, potentially hampering myocardial recovery. Thus, the purpose of this study was to evaluate the effect of LV unloading with the Impella pump (Abiomed, Inc.) on mortality in CS patients treated with VA-ECMO.
Data were collected from 686 consecutive patients with CS treated with VA-ECMO with LV unloading using an Impella (337 patients, 49%) or without LV unloading (349 patients, 51%) at 16 tertiary-care centers in four countries. The primary endpoint was 30-day all-cause mortality; safety endpoints assessed bleeding complications, ischemic complications, and other complications.
The association between LV unloading and 30-day mortality was assessed by Cox regression models in a 1:1 propensity-score–matched cohort. After matching, 255 patients with LV unloading were compared with 255 patients without.
The investigators reported the following in Circulation:
LV unloading was associated with lower 30-day mortality without differences in various subgroups (hazard ratio, 0.79; 95% CI 0.63-0.98; P = .03)
However, complications occurred more frequently in patients with LV unloading compared to those without: severe bleeding in 98 (38.4%) vs 45 (17.9%); access site–related ischemia in 55 (21.6%) vs 31 (12.3%); abdominal compartment in 23 (9.4%) vs 9 (3.7%); renal replacement therapy in 148 (58.5%) vs 99 (39.1%)
Overall, investigators concluded that these findings support the use of LV unloading in CS patients treated with VA-ECMO and call for further evaluation of this treatment strategy in a randomized controlled trial.