Comparison of left ventricular unloading strategies on venoarterial extracorporeal life support

Abstract

Objectives: Our goal was to compare the haemodynamic effects of different mechanical left ventricular (LV) unloading strategies and clinical outcomes in patients with refractory cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Methods: A total of 448 patients supported with VA-ECMO for refractory cardiogenic shock between 1 March 2015 and 31 January 2020 were included and analysed in a single-centre, retrospective case-control study. Fifty-three patients (11.8%) on VA-ECMO required LV unloading. Percutaneous balloon atrial septostomy (PBAS), intra-aortic balloon pump (IABP) and transapical LV vent (TALVV) strategies were compared with regards to the composite rate of death, procedure-related complications and neurological complications. The secondary outcomes were reduced pulmonary capillary wedge pressure, pulmonary artery pressure, central venous pressure, left atrial diameter and resolution of pulmonary oedema on a chest X-ray within 48 h.

Results: No death related to the LV unloading procedure was detected. Reduction in pulmonary capillary wedge pressure was highest with the TALVV technique (17.2 ± 2.1 mmHg; P < 0.001) and was higher in the PBAS than in the IABP group; the difference was significant (9.6 ± 2.5 and 3.9 ± 1.3, respectively; P = 0.001). Reduction in central venous pressure with TALVV was highest with the other procedures (7.4 ± 1.1 mmHg; P < 0.001). However, procedure-related complications were significantly higher with TALVV compared to the PBAS and IABP groups (50% vs 17.6% and 10%, respectively; P = 0.015). We observed no significant differences in mortality or neurological complications between the groups.

Conclusions: Our results suggest that TALVV was the most effective method for LV unloading compared with PBAS and IABP for VA-ECMO support but was associated with complications. Efficient LV unloading may not improve survival.

Keywords: Left ventricular unloading; Percutaneous balloon atrial septostomy; Transapical left ventricular vent; Venoarterial extracorporeal membrane oxygenation.

Figure 1:

Overview of study flow diagram. BIVAD: biventricular assist device; LV: left ventricle; RCS: refractory cardiogenic shock; RV: right ventricle; VA-ECMO: venoarterial extracorporeal membrane oxygenation.

Figure 2:

Haemodynamic changes after 3 different left ventricular unloading strategies. CVP: central venous pressure; LV: left ventricle; PCWP: pulmonary capillary wedge pressure; SPAP: systolic pulmonary artery pressure.

Figure 3:

Chest X-ray illustrations of the resolution of pulmonary oedema before and 48 h after LV unloading procedures. IABP: intra-aortic balloon pump; LV: left ventricle; PBAS: percutaneous balloon atrial septostomy; TALVV: transapical left ventricular vent.