Incidence of Neurological Events in Patients Supported with ECOPELLA

Background:
Venoarterial extracorporeal membrane oxygenation (ECMO) is used to support cardiogenic shock patients. It increases the risk of left ventricular afterload, for which unloading with an Impella device (Danvers –MA) is often necessary, hence the term ECOPELLA. The incidence of adverse neurologic outcomes (ANO) –Defined as imaging evidence of stroke or intracranial bleeding is not fully known in this group of patients, nor is the optimal anticoagulation strategy.

Methods:
This was a retrospective analysis of all patients supported at a single center with both devices simultaneously looking at ANO and time-in-therapeutic range (TTR) for partial thromboplastin time (PTT), defined as PTT >40. TTR was calculated using the Rosenthal Method.

Results:
Between 2015 and 2018, a total of 18 patients (mean age of 58.7, 94.4% males) were supported with both devices, with mean support duration of 7.65 days. Average time on ECMO was 9.5 days, and was 11.27 days on Impella (2.5 and CP). All patients were anticoagulated with heparin, and PTT was checked at least every 24 hours. Seven out of the 18 (38.88%) of patients suffered an ANO that was confirmed by a neurologist and a radiologist. Of the ANO patients, 6 of which were embolic, and one was hemorrhagic. Correlation between ANO and duration of support did not reach a level of statistical significance. Patients with ANO had TTR of 74.73% compared to TTR of 90.35% in those who did not have ANO (n=11), p of 0.09. There was no difference between low PTT target (40-70) and high PTT target (70-110) with respect to ANO.

Conclusions:
A trend toward ANO is seen in this small population of ECOPELLA patients who spend more time below therapeutic range in PTT. We hypothesize that a larger sample size is needed to evaluate optimal anticoagulation strategy in these patients.