February 4, 2019

Dear Cardiologists, Cardiothoracic Surgeons and Transplant Surgeons,

The FDA is evaluating recent interim post-approval study (PAS) results which suggest a higher mortality rate for patients treated with the Abiomed Impella RP System than the rate previously observed in the premarket clinical studies. The Impella RP System is a temporary right heart pump system intended to help patients maintain stable heart function without open chest surgery. The FDA wants to ensure you are aware of the mortality rate that has been observed in the ongoing PAS.

Although the FDA is concerned about the high mortality rate from the interim PAS results, we believe that when the device is used for the currently approved indication in appropriately selected patients, the benefits of the Impella RP system continue to outweigh the risks. Our current analysis of these results and recommendations for health care providers who may use the Impella RP System follow below. 

BACKGROUND

The FDA approved the Impella RP System on September 20, 2017. The device is implanted centrally via peripheral access to help patients who require temporary emergency support of right ventricular function. Use of the device, which may be up to 14 days, requires patients to stay in the hospital. 

In the premarket clinical studies, where strict inclusion and exclusion criteria were followed, a total of 44 out of 60 patients (73.3 percent) survived to 30 days post device explant or hospital discharge (whichever was longer), or to the start of next longer term therapy, including heart transplant or implantation of a surgical right ventricular assist device (RVAD).  

The FDA mandated the firm, Abiomed, to conduct a PAS as a condition of approval for the Impella RP System. The Impella RP PAS will follow 60 newly treated patients for one year through the firm’s cVAD registry.  The primary endpoint is survival to 30 days post device explant or hospital discharge (whichever is longer), or to the start of next longer term therapy.  Interim results from the most recent PAS report, which reflect device use in a broader patient population, indicate that only 4 out of the 23 enrolled PAS patients (17.4 percent) met the primary survival endpoint.

The FDA required additional analyses from Abiomed, and data submitted by the firm in January 2019 suggest that the high mortality rate observed in the PAS may be primarily related to differences in pre-implant characteristics of the PAS patients compared to the patients in the premarket clinical studies. Sixteen (16) of the 23 patients enrolled in the PAS would not have met the enrollment criteria for the premarket clinical studies. Specifically, before getting the Impella RP system implanted, patients in the PAS were more likely than the premarket clinical study patients to have been in cardiogenic shock for longer than 48 hours, experienced an in-hospital cardiac arrest, been treated with an intra-aortic balloon pump, or suffered a pre-implant hypoxic or ischemic neurologic event.  

It is important to note that the Impella RP PAS and FDA’s evaluation into this issue are ongoing.  We do not know the root cause for the high mortality rate, and the results are not adjusted for potential confounders.

RECOMMENDATIONS

The FDA has the following recommendations for health care providers:

• Be aware that FDA approval of the Impella RP System was based on the results of premarket clinical studies that included patients who had been in cardiogenic shock for less than 48 hours prior to device implant.  Additionally, none of the patients in the premarket clinical studies experienced an in-hospital cardiac arrest, or were treated with an intra-aortic balloon pump, or suffered a hypoxic or ischemic neurologic event, prior to Impella RP being implanted. Although these clinical events may not preclude a clinical decision to use the device, physicians should be aware that the occurrence of one or more of these events prior to Impella RP implantation may decrease expected survival rate. 
• Carefully consider these interim survival results from the ongoing PAS when making treatment decisions and discuss the risks and benefits of the Impella RP System with patients and their caregivers. Additionally, be aware that there are currently no other device interventions that have been approved by the FDA under the premarket application (PMA) process for the patient population demonstrating a higher mortality rate in the PAS and as such, other interventions pose risks, as well, that should be considered and discussed with patients and their caregivers.
• Report any adverse events or suspected adverse events experienced with the Impella RP System:
  • Voluntary reports can be submitted through MedWatch, the FDA Safety Information and Adverse Event Reporting program.
  • Device manufacturers and user facilities must comply with the applicable Medical Device Reporting (MDR) regulations.
  • Health care personnel employed by facilities that are subject to the FDA's user facility reporting requirements should follow the reporting procedures established by their facilities.

Prompt reporting of adverse events can help the FDA identify and better understand the risks associated with medical devices.

FDA ACTIONS

The FDA will continue to review data from the ongoing PAS, and other available data sources as they become available. The FDA will work with Abiomed to ensure the product labeling addresses the PAS interim results. We will continue to keep the public informed if new or additional information becomes available.

CONTACT US

If you have questions about this communication, please contact the Division of Industry and Consumer Education (DICE) at [email protected], 800-638-2041 or 301-796-7100.

Sincerely,
/s/
William Maisel, MD, MPH
CDRH Chief Medical Officer
Center for Devices and Radiological Health
U.S. Food and Drug Administration