risk of AKI study

Use of Impella® Device During High-Risk PCI is Associated with Reduced Occurrence of Acute Kidney Injury

May 15, 2017

Patients undergoing complex coronary revascularization are at risk for periprocedural and postprocedural acute kidney injury (AKI), a complication which correlates with an increased risk of death, major bleeding, and myocardial infarction (MI).1 A reduction in cardiac output and renal hypoperfusion, which in turn leads to a decrease in glomerular filtration rate, may partly explain the increased risk for AKI during high-risk percutaneous coronary intervention (HRPCI).1

Currently, there are few published studies which examine the impact of micro-axial percutaneous left ventricular assist devices on AKI in patients undergoing HRPCI.

Study Objective and Design

In the journal Circulation Research, Flaherty MP et al examined whether partial hemodynamic support with the Impella 2.5® device protected patients from developing AKI during HRPCI.1 The retrospective, single-center study enrolled 230 patients undergoing HRPCI and included 115 patients receiving Impella 2.5 support matched with a control group of 115 patients not receiving the device. On average, patients had a left ventricular ejection fraction (LVEF) of ≤35%. Typically, patients with severely reduced LVEF are at a greater risk for AKI because they require longer procedures, more complete revascularization, and greater contrast administration.

The primary outcome for this study was in-hospital AKI during a 72-hour periprocedural time frame.


Patients receiving hemodynamic support with Impella 2.5 had a significantly greater number of comorbidities and longer procedure time, factors which predisposed them to a higher risk for AKI. This patient group is also more likely to receive greater contrast, which further increases their risk.

Despite a greater number of risk factors, Impella-supported patients experienced significantly less AKI than patients not receiving support (5.2% vs 27.8%, respectively). Only 0.9% of patients receiving the Impella device required post-procedural hemodialysis vs 6.1% of patients without Impella (p<0.05).

Those receiving the Impella heart pump also had a shorter length of stay compared with unsupported patients, despite there being a greater baseline hazard for the patients in the Impella arm. Nonetheless, supported patients had a lower rate of contrast nephropathy.

Greater Comorbidities, Lower Risk for AKI in Impella Arm

Patients with a greater incidence of comorbidities, including diabetes and baseline renal insufficiency, are at an even higher risk for AKI. An analysis of the patient population studied in this retrospective, single-center study demonstrated that the subgroup supported by the Impella device had far greater comorbidities than unsupported patients, yet supported patients experienced greater overall protection. This finding suggests the importance of considering Impella device support during HRPCI in select patients.


These physicians agreed that Impella 2.5 successfully protected against AKI during HRPCI, and using this device in high-risk PCI may provide an added value to those high-risk patients with compromised kidneys by maintaining additional renal protection in those select patients. The findings of this study, which are consistent with the PROTECT II2 randomized control trial, may bolster interventionalists’ confidence in performing complete revascularization in patients with complex coronary artery disease who are also at risk for AKI.

Although it isn’t entirely clear how the Impella heart pump provides a protective benefit against AKI, there is speculation that it may relate to the device’s ability to provide continuous flow, thus reducing periprocedural renal hypoperfusion.

To learn more about this study, read Abiomed’s official press release.


  1. Flaherty MP, Pant S, Patel SV, et al. Hemodynamic Support With a Microaxial Percutaneous Left Ventricular Assist Device (Impella) Protects Against Acute Kidney Injury in Patients Undergoing High-Risk Percutaneous Coronary Intervention. Circ Res. 2017;120(4):692-700.
  2. O'Neill WW, Kleiman NS, Moses J, et al. A prospective, randomized clinical trial of hemodynamic support with Impella 2.5 versus intra-aortic balloon pump in patients undergoing high-risk percutaneous coronary intervention: the PROTECT II study. Circulation. 2012;126(14):1717-1727.


To learn more about the Impella® platform of heart pumps, including important risk and safety information associated with the use of the devices, please visit: www.protectedpci.com/indications-use-safety-information/

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