Timing of Active Left Ventricular Unloading in Patients on Venoarterial Extracorporeal Membrane Oxygenation Therapy.

BACKGROUND: It is currently unclear if active left ventricular (LV) unloading should be used as a primary treatment strategy or as a bailout in patients with cardiogenic shock (CS) treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO). OBJECTIVES: This study sought to evaluate the association between timing of active LV unloading and implantation of VA-ECMO with outcomes of patients with CS. METHODS: Data from 421 patients with CS treated with VA-ECMO and active LV unloading at 18 tertiary care centers in 4 countries were analyzed. Patients were stratified by timing of device implantation in early vs delayed active LV unloading (defined by implantation before up to 2 hours after VA-ECMO). Adjusted Cox and logistic regression models were fitted to evaluate the association between early active LV unloading and 30-day mortality as well as successful weaning from ventilation. RESULTS: Overall, 310 (73.6%) patients with CS were treated with early active LV unloading. Early active LV unloading was associated with a lower 30-day mortality risk (HR: 0.64; 95% CI: 0.46-0.88) and a higher likelihood of successful weaning from ventilation (OR: 2.17; 95% CI: 1.19-3.93) but not with more complications. Importantly, the relative mortality risk increased and the likelihood of successful weaning from ventilation decreased almost proportionally with the time interval between VA-ECMO implantation and (delayed) initiation of active LV unloading. CONCLUSIONS: This exploratory study lends support to the use of early active LV unloading in CS patients on VA-ECMO, although the findings need to be validated in a randomized controlled trial.

Left Ventricular Unloading Is Associated With Lower Mortality in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: Results From an International, Multicenter Cohort Study.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to treat cardiogenic shock. However, VA-ECMO might hamper myocardial recovery. The Impella unloads the left ventricle. This study aimed to evaluate whether left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO was associated with lower mortality. METHODS: Data from 686 consecutive patients with cardiogenic shock treated with VA-ECMO with or without left ventricular unloading using an Impella at 16 tertiary care centers in 4 countries were collected. The association between left ventricular unloading and 30-day mortality was assessed by Cox regression models in a 1:1 propensity score-matched cohort. RESULTS: Left ventricular unloading was used in 337 of the 686 patients (49%). After matching, 255 patients with left ventricular unloading were compared with 255 patients without left ventricular unloading. In the matched cohort, left ventricular unloading was associated with lower 30-day mortality (hazard ratio, 0.79 [95% CI, 0.63-0.98]; P=0.03) without differences in various subgroups. Complications occurred more frequently in patients with left ventricular unloading: severe bleeding in 98 (38.4%) versus 45 (17.9%), access site-related ischemia in 55 (21.6%) versus 31 (12.3%), abdominal compartment in 23 (9.4%) versus 9 (3.7%), and renal replacement therapy in 148 (58.5%) versus 99 (39.1%). CONCLUSIONS: In this international, multicenter cohort study, left ventricular unloading was associated with lower mortality in patients with cardiogenic shock treated with VA-ECMO, despite higher complication rates. These findings support use of left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO and call for further validation, ideally in a randomized, controlled trial.