The FDA has issued a letter to health care providers regarding the increased rate of mortality in patients who have received a temporary right heart pump system in a recent interim postapproval study compared with what was previously observed in premarket clinical studies.
The temporary right heart pump (Impella RP system, Abiomed) is used to maintain stable heart function without open heart surgery, according to a letter from the FDA.
The right heart pump system was approved by the FDA in 2017 to maintain stable heart function for up to 14 days without open heart surgery in patients with acute right HF or decompensation after left ventricular assist device implantation, MI, heart transplant or open heart surgery.
“Although the FDA is concerned about the high mortality rate from the interim [postapproval study] results, we believe that when the device is used for the currently approved indication in appropriately selected patients, the benefits from the Impella RP system continue to outweigh the risks,” William Maisel, MD, MPH, chief medical officer for the Center for Devices and Radiological Research at the FDA, said in the letter.
Premarket clinical studies found that 73.3% of patients survived 30 days after the device was explanted or hospital discharge, or when the next longer-term therapy was to be initiated, according to the letter. Abiomed then performed a postapproval study at the request of the FDA and found that 17.4% of patients met the primary survival endpoint at 30 days after device explant, hospital discharge or the initiation of the next longer-term therapy.
Data submitted by Abiomed to the FDA in January found that there was a higher mortality rate in the postapproval study, which may be associated with differences in pre-implant characteristics in patients from the postapproval study vs. those in the premarket clinical studies, according to the letter. Of the 23 patients who were enrolled in the postapproval study, 16 would not have been eligible for the premarket clinical studies.
“It is important to note that the Impella RP [postapproval study] and FDA’s evaluation into this issue are ongoing,” Maisel said. “We do not know the root cause for the high mortality rate, and the results are not adjusted for potential confounders.”
The FDA recommends that health care providers are aware that its approval was based on results from the premarket clinical studies, which included patients who were in cardiogenic shock for less than 48 hours before device implantation, according to the letter. In addition, health care providers should consider the interim survival results from the postapproval study while making decisions with their patients. Any suspected adverse events related to this device should be reported to the FDA and device manufacturers, according to the letter.
Disclosure: Maisel is an employee of the FDA.