First in man evaluation of a novel circulatory support device: Early experience with the Impella 5.5 after CE mark approval in Germany

Background: The Abiomed Impella 5.5 (Danvers, MA) is a newly developed axial flow transaortic cardiac support device mounted on a 9 Fr steering catheter with a 21 Fr pump cannula. Impella 5.5 is intended for longer use and was approved for 30 days in 2018. This study evaluated the first-in-man series at six high-volume mechanical circulatory support centers in Germany after CE approval.

Methods: The first 46 consecutive patients worldwide underwent implantation in six German centers between March 2018 and September 2019 for post-CE approval evaluation. The primary end-point was 30 days and 90 days all-cause mortality.

Results: The mean age of patients was 59.0 ± 11.5 years, and 43 (93.4%) were men. Half of the patients had acute on chronic heart failure. The main indication for Impella 5.5 implantation was ischemic cardiomyopathy and acute myocardial infarction (47.8%). The mean support time was 15.5 ± 24.2 days (range 0-164, median 10 days (IQR = 7-19)) with a total of 712 patient-days on support. The 30 days and 90 days survival rates were 73.9% (95% CI: 63.3-88.9%) and 71.7% (95% CI: 60.7-87.1%), respectively. Additionally, 16 patients (34.8%) were weaned from the device for native heart recovery, and 19 (41.3%) were bridged to a durable device. Fifteen patients (32.6%) were mobilized to a chair, and 15 (32.6%) were ambulatory. We only noted one stroke and found no other thromboembolic complications. No aortic valve damage was observed in the study cohort. Finally, seven patients (15.2 %) had pump thrombosis, and nine (19.6 %) underwent device exchange. Sixteen patients (34.8 %) suffered from bleeding requiring transfusions during the whole treatment course. In ten patients (21.7%), the inflow cannula dislocated into the aortic root.

Conclusions: The first version of the Impella 5.5 presents promising early outcomes for patients with acute heart failure and expands the spectrum of available devices. The adverse event profile is favorable for short-term devices. Dislocations have been addressed by design changes. With increasing experience with this device, our study suggests that the indications for use will expand to other cardiac shock etiologies and may improve myocardial recovery and survival in patients with cardiogenic shock.