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

AimsEvidence 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 resultsThis 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.ResultsOf 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.ConclusionsLV 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.