Impella RP Mortality Rate No Longer a Concern, FDA Says

Today the US Food and Drug Administration released an update saying that final postapproval study (PAS) results for the Impella RP system (Abiomed) now alleviate concerns about a potential mortality signal previously seen with the percutaneous device. The FDA also has released new labeling.

With the latest data, “the survival rate for the subgroup of PAS patients who would have met the enrollment criteria for the premarket clinical studies is consistent with the premarket clinical studies survival rate and further confirms that the device is safe and effective when used for the currently approved indication,” according to the agency’s announcement.

The final results show a 69.7% survival rate for the PAS patients who would have been eligible to enroll in premarket clinical studies. Survival was defined as living to 30 days postexplant or hospital discharge (whichever was longer), or to heart transplant or receipt of a surgically implanted right ventricular assist device.

For those who would not have met enrollment criteria, however, the survival rate was just 18.6%. “In these patients, the PAS survival rate should be interpreted in the context of the patients' conditions and limited treatment options,” the FDA specifies, adding that such patients “were more likely to have been in acute right heart failure or decompensation for longer than 48 hours and experienced a severe cardiogenic shock, end-organ failure, or acute neurologic injury.”

Thus, the FDA has tweaked the product label and, in today’s statement, highlighted the newly updated sections in italics:

“The Impella RP System is indicated for providing temporary right ventricular support for up to 14 days in patients with a body surface area ≥ 1.5 m², who develop acute right heart failure or decompensation for less than 48 hours following left ventricular assist device implantation, myocardial infarction, heart transplant, or open‐heart surgery, without the presence of profound shock, end-organ failure, or acute neurologic injury.”

From Approval to Real-World Use

The agency first approved Impella RP in September 2017 based on premarket clinical studies—with strict inclusion and exclusion criteria—showing a survival rate of 73.3%.

But in a February 2019, the FDA announced troubling interim results from the agency-mandated PAS. In this broader population, just four out of 23 patients (17.4%) survived 30 days after explant or hospital discharge, or to heart transplant or receipt of a surgically implanted right ventricular assist device. At the time, the agency said: “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.”

A subsequent update was released in May 2019, at which point the survival rate among 42 PAS patients had reached 28.6%.

With their latest announcement, the FDA recommends that healthcare professionals read and follow the current Impella RP labeling, discuss the risks and benefits of the product with patients and their caregivers, and appropriately report any adverse events with the device.