Biventricular unloading with impella and venoarterial extracorporeal membrane oxygenation in severe refractory cardiogenic shock: prognosis and implications from the combined use of the devices
Authors: Syntila S , Markus B , Ahrens H , Luesebrink U , Waechter C , Karatolios K , Divchev D , Sassani K , Schieffer B , Chatzis G 
Published: October 2022

Abstract

Background
Patients with refractory cardiogenic shock (RCS) may present with left ventricle (LV)-failure, biventricular failure or even combined cardiopulmonary failure. Mechanical support with Impella or veno-arterial membrane oxygenation (VA-ECMO) have emerged as an alternative strategy in order to stabilize the heart function without the detrimental effects of catecholamines or to bridge the patients in definite therapies. However, the selection of the appropriate MCS should be tailored according to the underlying pathophysiology and properties of the respective MCS device. Patients with Impella who initially presented with univentricular LV failure may develop additionally right ventricle (RV) dysfunction or pulmonary failure whereas patients with VA-ECMO may show signs of LV overloading, causing pulmonary edema, LV distension and thus compromising LV myocardial recovery.

Purpose
To present the main outcomes and predictors of survival and safety in RCS treated with Impella and VA-ECMO.

Methods
Single center study of consecutive patients with biventricular unloading with Impella and VA-ECMO for RCS admitted to Cardiology department of Philipps University in Marburg, Germany, from February 2013 until December 2019. The selection of the device was based on a standard algorithm (Figure 1).

Results
A total of 67 patients was included in the study. Mean age was 61.07±10.7 and 54 (80.6%) patients were male. Main cause of RCS was acute myocardial infarction (AMI) (74.6%), while 44 (65.7%) were resuscitated prior to admission. In 28 patients Impella was implanted first, whereas VA-ECMO was the first MCS device in 39 patients. The mean Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment Score (SOFA) score on admission was 73.54±16.03 and 12.25±2.71, respectively, corresponding to an expected mortality of higher than 80%. Vasopressor doses and lactate levels were significantly decreased within 72 h on biventricular support (p&lt;0.05 for both). Overall, 17 (25.4%) patients were discharged to cardiac rehabilitation and 5 patients (7.5%) were bridged successfully to ventricular assist device implantation, leading to a total of 32.8% survival on hospital discharge. The 6-month survival was 31.3%. Lactate &gt;6 mmol/L, vasoactive score &gt;100 and pH &lt;7.26 on initiation of biventricular support, as well as Charlson comorbity index (CCI) &gt;3 and prior resuscitation were independent predictors of survival (Figure 2).

Conclusions
Biventricular support with Impella and VA-ECMO in patients with RCS is feasible and efficient leading to a better survival than predicted through traditional risk scores, mainly via significant hemodynamic improvement and reduction in lactate levels. Lactate, pH and vasoactive score on initiation of biventricular support, as well as age-adjusted CCI and prior resuscitation are independent risk factors associated with mortality in this group of patients.

Funding Acknowledgement
Type of funding sources: None.