TCT 2024: J&J’s Abiomed clears pivotal study for shrinkable heart pump

WASHINGTON, D.C.—Johnson & Johnson MedTech’s Abiomed announced that its compressible, expandable heart pump has cleared a pivotal trial, and it’s now headed for FDA review in the coming months.

The Impella ECP represents a redesign of the 12-year-old Impella CP, with a structure that allows it to shrink in size as it enters and navigates the body’s blood vessels—before extending to full size and pumping strength once it reaches the inside of the heart.

Abiomed Impella ECP
The Impella ECP.  (Abiomed)

Described by the company as the world’s smallest heart pump, the Impella ECP requires only a 9 French-sized delivery sheath, or only 3 millimeters wide, compared to its predecessor’s 14 French catheters.

“That’s pretty significant when you’re talking about a blood vessel that’s only 5 millimeters in diameter, such as the femoral artery,” Abiomed’s chief medical officer, Charles Simonton, said in an interview during the Cardiovascular Research Foundation’s Transcatheter Cardiovascular Therapeutics conference in Washington, D.C.

“When it’s fully expanded, the Impella ECP is actually bigger than the Impella CP, at 21 French,” added Simonton, who said that with its compressible two-bladed, polyurethane rotor, the ECP still ends up delivering about the same amount of flow as it straddles the heart’s aortic valve and pumps blood into the aorta.

The company’s pivotal trial, which had its results presented at the TCT conference this week, enrolled 256 patients. The study met its primary endpoint, posting a rate of major adverse cardiac and cerebrovascular events, such as stroke and death, of 6.3% after 30 days, to come in under a predefined safety goal.

Simonton said Abiomed aims to first secure an FDA approval for the device solely in high-risk percutaneous coronary interventions, where it can be used for up to six hours—compared to the CP, which can also be employed in the treatment of cardiogenic shock for up to four days—and that the ECP will offer clinicians a new choice when considering a patient’s anatomy.

“If they’re concerned that putting in the larger 14 French sheath may be a problem, in terms of the size of their artery—or if they have peripheral vascular disease, or their age, or things like that—they might choose the ECP,” he said.

“But once the ECP gets up and going, and the doctors get more comfortable with it, they’ll probably use it in most of their high-risk PCI procedures. Even in a patient that could accept a larger sheath, you don’t want to have to use it, because a larger bore does increase the bleeding risk.”

Also at TCT, three subanalyses of data from the company’s DanGer Shock trial explored how Impella pumps help the body recover from a severe heart attack and cardiogenic shock, as well as the devices’ recorded risks of bleeding events and renal damage.

The first results from the decade-long DanGer Shock study were presented earlier this year at the annual scientific session of the American College of Cardiology in Atlanta, and published in the New England Journal of Medicine.

The trial found that employing Impella CP led to increases in six-month survival rates among people who suffered an ST-elevated myocardial infarction, or a STEMI. About 10% of STEMI cases include cardiogenic shock, and together they carry mortality rates approaching 50%, and often within 24 hours.

One of the main takeaways from the follow-up presentations at TCT was the Impella’s ability to aid in the faster clearance of lactic acid from the bloodstream—which builds up during cardiogenic shock, as the body redirects oxygen towards the brain and vital organs and away from the muscles in the arms and legs in a bid to survive.

“That's important because it determines how quickly the patients can actually recover, with their bloodstream and whole metabolism,” Simonton said. “So there's a rapid recovery with the Impella in terms of reversing that metabolic acidosis that patients are getting from not having enough oxygen. It also resulted in patients requiring less vasopressor medications to keep the blood pressure up, and that has a lot to do with washing out the lactate.”

When it came to bleeding, patients treated with Impella CP did have more adverse events and transfusions, which Simonton attributed to the requirement of the larger bore.

“Despite the fact that there was more bleeding, there was still a reduction in mortality by Impella,” he said. “And bleeding was not a predictor of mortality, so that was a really interesting finding.”

Finally, researchers reported a higher rate of acute kidney injuries, with many patients receiving renal replacement therapy within the first 24 hours after hospital admission. Acute kidney injuries were also associated with a higher risk of six-month mortality, however, Impella still reduced overall mortality compared to the control group regardless of renal status.