FDA UPDATE: Increased rate of mortality in patients receiving Abiomed Impella RP System

The Food and Drug Administration (FDA) has issued an update to its February 4, 2019 letter to healthcare providers, particularly cardiologists, cardiothoracic surgeons and transplant surgeons, of the most recent, interim post-approval study (PAS) results for Abiomed's Impella RP System. These latest interim results, which are available on the FDA Post-Approval Studies webpage, indicate a lower survival rate for the subgroup of PAS patients who would not have qualified for the premarket clinical studies compared to the premarket clinical study survival rate.

The FDA also said 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.

Interim results from the most recent Impella RP System PAS report indicate that 12 out of the 42 enrolled PAS patients (28.6 percent) survived to 30 days post device explant or hospital discharge, or to the start of next longer-term therapy. In the premarket clinical studies, the survival rate was 73.3 percent. The primary reason for the difference in survival outcome appears to be patient selection.

FDA explained in the letter that for the subgroup of PAS patients who would have met the enrollment criteria for the premarket clinical studies, the survival rate was 64.3 percent (9 out of 14 patients) which is similar to the premarket clinical study survival rate. For the subgroup of PAS patients who would not have qualified for the premarket clinical studies, the survival rate was 10.7 percent (3 out of 28 patients). In these patients, the PAS survival rate should be interpreted in the context of the patients' conditions and limited treatment options.

PAS patients who would not have qualified for the premarket clinical studies were more likely to have been in cardiogenic shock for longer than 48 hours, experienced a cardiac arrest, or suffered a pre-implant hypoxic or ischemic neurologic event before getting the Impella RP system implanted compared to the PAS patients who would have met the enrollment criteria for the premarket clinical studies.

The FDA recommends that healthcare providers read and follow the revised labeling for Abiomed's Impella RP System, which includes a patient selection checklist to understand which patients may benefit the most from treatment with the Impella RP System.

The FDA continues to recommend that healthcare providers:

·   Be aware that the 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. As such, other interventions may include their own benefits and risks 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.

·    Healthcare 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.

The Impella RP System PAS and the FDA's evaluation are ongoing. In April 2019, the FDA approved revised labeling for Abiomed's Impella RP System to include more information about patient selection and which patients may benefit the most from treatment with the device. In addition, the FDA required Abiomed to make changes to the design of the PAS to include subgroup analyses, and to establish a minimum number of patients in each subgroup. Details of the study protocol are posted on the FDA's Post-Approval Studies webpage.