Authors (including presenting author) :
Au SY(1), Tsang CFS(2), Fong KM(1), Chan KCA (2), Wong CY(2), Ng WYG(1), Lee KYM(2)
Affiliation :
(1) Intensive Care Unit, Queen Elizabeth Hospital (2) Cardiology, department of Medicine, Queen Elizabeth Hospital
Introduction :
Venoarterial extracorporeal membrane oxygenation (VA-ECMO) could provide full cardiac support in refractory cardiogenic shock. Peripheral VA-ECMO, in which the return catheter is at the common femoral artery, offers circulatory support via retrograde flow, which will in turn increase the left ventricular afterload, resulting in acute pulmonary edema and intracardiac thrombosis. There has been evidence that prophylactic uploading of the left heart might improve clinical outcomes in patients at risk of left ventricular distension. In our unit, the intensive care unit (ICU) of Queen Elizabeth Hospital, prophylactic left ventricular unloading, by means of either intra-aortic balloon pump (IABP) or more recently, Impella, is performed. The Impella (Abiomed) is a family of ventricular support device which consists of a microaxial pump mounted on a nine French support catheter inserted by cardiologists. Both the IABP and Impella serve 2 purposes when used in combination with VA-ECMO: for left ventricular venting while still on VA-ECMO and as a bridge support upon ECMO weaning. In this study, we would like to investigate any outcome difference and rate of complications between the two groups of combination therapy.
Objectives :
To see if the new technique of ECMO-Impella combination resulted in better clinical outcomes as compared with the conventional ECMO-IABP combination.
Methodology :
This was a retrospectively data analysis. Inclusion criteria would be all patients aged >= 18 who had ECMO support and had left ventricular venting by either IABP or Impella in adult ICU, Queen Elizabeth Hospital, between 1 January 2018 and 31 October 2020. Patients who were aged < 18 years old, patients who had ECMO managed in other hospitals, patients had central VA-ECMO, patient who suffered post craniotomy shock, patients not requiring left ventricular venting or patient who had surgical venting techniques were excluded from the current study. The primary outcome was ECMO duration. Other major outcomes included ICU length of stay (LOS), hospital LOS, mortality and rate of complications.
Result & Outcome :
The baseline characteristics were comparable between the ECMO-IABP group and the ECMO-Impella groups in terms of age, gender, and disease severity by APACHE II and IV scores. The ECMO duration was shortened in the ECMO-Impella group as compared with the ECMO-IABP groups, though not reached statistical significance. ( 2.5days vs 4.6days, p=0.147 ). This remained true if only ECMO survivors were included. ( 2.9days vs 5.4days, p=0.019). ICU LOS was shortened in the ECMO-Impella group as compared with the ECMO-IABP groups ( 7.7days vs 10.8days, p=0.367 ) and this again remained true if only ICU survivors were included, though not statistically significant. (6.4days vs 11.7days, p=0.363 ). The Hospital LOS was also shortened in the ECMO-Impella group as compared with the ECMO-IABP group ( 14.8days vs 16.5 days, p=0.556 ) and this remained true if only hospital survivors were included though not statistically significant.(24.5days vs 28.2days, p=0.914) The mortality rate, and rate of complications, were comparable between the 2 groups. Conclusion: The new technique of Impella in combination of VA-ECMO, for left ventricular venting and as a bridge circulatory support, resulted in better clinical outcomes as compared with the conventional ECMO-IABP combination. The lack of statistical significance in the primary outcomes was due to the small sample size. However, given the great clinical difference in clinical outcomes, statistically favorable outcomes with the ECMO-Impella combination will be demonstrated if more data are available.
