Abstract
Background
Selective groups of patients, presenting with INTERMACS-1 cardiogenic shock due to acute ischaemic heart failure, may benefit from mechanical circulatory support (MCS). Patients with biventricular failure, severe septic shock or oxygenation problems should be selected for VA-ECMO, although the left Impella-CP heart pump can be considered as a less invasive alternative in supporting predominantly left ventricular failure. Bleeding issues are a major concern in patients on MCS, especially in this group where triple anticoagulation therapy (unfractionated heparin (UFH) for prevention of pump thrombosis and dual antiplatelet therapy (DAPT) after coronary stenting) is necessitated. We aim to investigate the bleeding and transfusion rate in DAPT-patients on VA-ECMO versus Impella.
Methods
We report single center data for 51 VA-ECMO and 8 Impella patients between 2011 and 2019. Indication for MCS was acute ischaemic cardiogenic shock. Patient demographics, transfusions and reported/radiographically diagnosed bleeding (BARC-classification) complications were analyzed. All patients received UFH and low dose aspirin plus clopidogrel or ticagrelor. Impella flow was at least 2.5 L/min. Transfusion targets were Hb >7 g/dl, fibrinogen >100 mg/dl (or >150 mg/dl when active bleeding) and platelet count >50/fL.
Results
Impella patients were significantly older (VA-ECMO 52.8 vs. Impella 62.4; p=0.02) as compared to the VA-ECMO group. Anti-Xa-levels and length of the MCS-run (mean 7.9 VA-ECMO vs. 6.4 days Impella) were comparable in both groups. Occurrences of minor bleeds was comparable between both groups (mainly oozing from the insertion site in the ImpellaTM group 63% vs. VA-ECMO 72%; p>0.05) but major bleedings with BARC score of 3 or more were significantly lower in the Impella group (13% vs. VA-ECMO 65%; p=0.005). Platelet and red blood cell transfusions were significantly lower in the Impella group (0.1 units of platelets per day vs. 1.1 units of platelets per day on VA-ECMO; p=0.002 and 0.8 units of RBCs per day vs. 2.6 units of RBCs per day on VA-ECMO; p=0.02).
Bleeding/transfusion VA-ECMO vs Impella
Conclusions
Bleeding is a frequent complication of MCS. However, in our cohort, triple anticoagulation in acute cardiogenic shock due to ischaemic left ventricle failure resulted in a lower major bleeding rate when support was given by the left Impella device as compared with VA-ECMO therapy group. As a result, platelet and red blood cell transfusions were lower in the Impella group. These findings are likely to be partly explained by the increased number and size of cannulas in VA-ECMO, as well as the increased risk of haemolysis and consumptive coagulopathy due to the complexity and extensive foreign body surface of the ECMO-circuit. We conclude that Impella support should be considered as a safer option than VA-ECMO with regards to bleeding in patients with ischaemic left ventricular failure who require DAPT and MCS as a bridge to recovery or other definitive therapy.
Unloading using Impella CP during profound cardiogenic shock caused by left ventricular failure in a large animal model: impact on the right ventricle
