Differential effect of left ventricular unloading according to the aetiology of cardiogenic shock

Abstract

Aims: Evidence for the effectiveness of left ventricular (LV) unloading in patients who received venoaterial extracorporeal membrane oxygenation (VA-ECMO) for acute myocardial infarction (AMI) or non-AMI induced cardiogenic shock (CS) is limited. The aim of the present study was to compare the effect of LV unloading in AMI-induced and non-AMI-induced CS. Methods and results: This is a single-centre retrospective observational study of patients with CS undergoing VA-ECMO from January 2011 to March 2019. Patients were classified as AMI-induced and non-AMI-induced CS. The association of LV unloading with 90-day mortality in both groups was analysed using Cox proportional hazard regression analysis. Results: Of the 128 CS patients, 71 (55.5%) patients received VA-ECMO due to AMI-induced CS, and the remaining 57 (44.5%) received VA-ECMO due to non-AMI-induced CS. The modality of LV unloading was predominantly with IABP (94.5%). In the AMI-induced CS group, LV unloading did not reduce 90-day mortality (adjusted hazard ratio 1.96, 95% confidence interval 0.90–4.27, P = 0.089). However, in the non-AMI-induced CS group, LV unloading combined with VA-ECMO significantly reduced 90-day mortality (adjusted hazard ratio 0.37, 95% confidence interval 0.14–0.96, P = 0.041; P for interaction = 0.029) as compared with those who received VA-ECMO alone. Conclusions: LV unloading with VA-ECMO may reduce 90-day mortality compared with VA-ECMO alone in patients with non-AMI-induced CS, but not in AMI-induced CS.