Outcomes with Impella in Cardiogenic Shock

Background The Impella (ABIOMED, Danvers, MA) is a temporary left ventricular support device, intended for short-term cardiac support for percutaneous procedures and cardiac shock. The Impella device is available in several sizes capable of producing different flows. It is FDA approved for up to 6 days of support. The device can provide significantly higher blood flow than an intra-aortic balloon pump and can be implanted percutaneously. We sought to describe potential complications and outcomes associated with extended Impella use for cardiogenic shock. Methods We retrospectively evaluated patients who underwent implantation of either the Impella CP (Impella 3.5) or Impella 5.0 from September 1, 2017 to September 1, 2019 at our institution. Hemolysis was defined as plasma free hemoglobin level > 50 mg/dL, a lactate dehydrogenase (LDH) level > 500 units/L, and bilirubin increase > 1 mg/dL. Results 58 patients underwent percutaneous insertion of an Impella device, with the indication of cardiogenic shock in 32 patients (55%). In these 32 patients, only one had an Impella 2.5 device, 21 had an Impella CP (66%), and 10 (31%) had an Impella 5.0. The average age at time of implantation was 55 ± 17 years, and 25 patients were male (78%). Ejection fraction was 17 ± 11.7%. The average duration of Impella support was 5.5 days (1, 16 days). Complications included hematoma at the time of insertion (3 patients), leg ischemia (2 patients), improper positioning (7 patients), acute renal failure (28 patients), and hemolysis (20 patients). Hemolysis developed in 12 patients (57%) with the Impella CP and in 8 patients (80%) with the Impella 5.0, with an average LDH of 1452 units/L. 8 patients were transitioned to veno-arterial (VA) extracorporeal membrane oxygenation (ECMO), with the Impella utilized for left ventricular venting. 9 patients (28%) eventually underwent durable left ventricular assist device (LVAD) implantation on average 7 ± 6.1 days after Impella, and two patients underwent heart transplantation, both 9 days following Impella insertion. 23 patients (72%) did not survive past the initial hospitalization. Conclusion The Impella is a percutaneous temporary left ventricular support device used to provide additional cardiac output in patients with cardiogenic shock. Serious complications can occur with extended support, including hemolysis, acute renal failure, and high mortality. Of our 28 patients who received an Impella, 11 were able to be successfully bridged to either LVAD or heart transplantation with the Impella.