Dr Meyns stated his intention to make a case for unloading in patients receiving extracorporeal membrane oxygenation (ECMO). He emphasised the increasing utilisation of ECMO in the treatment of acute cardiogenic shock (CS) due to technical ease of implantation at the bedside, transportability, oxygenation, immediate restoration of haemodynamics and the use as a bridge to decision. The survival to discharge of patients on ECMO varies from 41% for CS to 29% for extended cardiopulmonary resuscitation.1
He highlighted that incremental improvements in oxygenators, pumps, cannulas and management strategies have significantly reduced the incidence of adverse events with ECMO. Notwithstanding, major adverse events include bleeding and increased left ventricular (LV) afterload leading to LV distension of an already failing heart.
Unloading during ECMO helps avoid pulmonary congestion, improves myocardial recovery and reduces the risk of thrombus formation.2 There are multiple strategies for unloading the failing LV during veno-arterial ECMO support, such as apical/pulmonary/transaortic drainage catheter, Impella and reducing ECMO flow. He presented multiple cases of patients unloaded with the strategies mentioned above, particularly with Impella.
Dr Meyns shared the management algorithm for acute CS at his institution. The Impella is the preferred LV unloading device before revascularisation in patients presenting with CS, defined as aortic blood pressure <90 mmHg for >30 minutes with plasma lactate > 2 mmol/l. Following revascularisation, if the cardiac index <2.5, then the escalation of therapy is considered. In patients requiring CPR or presenting with predominant right ventricular failure, ECMO is the preferred device for unloading followed by unloading with Impella, if needed.
In 2018, 31 patients with CS were treated at his institution using the management strategy mentioned above. Of these, 17 were treated with Impella alone and 14 with ECMO plus Impella. The Impella CP was implanted in 15 and Impella 5.0 in 16 patients. In the ECMO plus Impella group, nine patients died, two were bridged to left ventricular assist device (LVAD) and three had recovery. In the Impella alone group, three patients died, five were bridged to LVAD and nine had myocardial recovery. The overall survival was 61%, which is better than historical controls. The mean duration of Impella support was 8.5 days with a maximum of 38 days, which is higher than the typical ECMO support. He further highlighted the advantage of axillary access for Impella 5.0, including long-term support with the ability to mobilise the patient.