Dive Brief:

• Two large observational studies found Abiomed's Impella heart device was associated with higher rates of bleeding and in-hospital deaths compared to use of an intra-aortic balloon pump (IABP), according to results presented Saturday at the American Heart Association's 2019 Scientific Sessions meeting in Philadelphia.

• Abiomed's chief medical officer, interventional cardiologist Seth Bilazarian, told MedTech Dive in an email Monday the study was "fundamentally flawed" because it was based on poor quality data that lumped the device's indications together. "In this data set, a patient walking in for an elective procedure looks the same as a patient in cardiac arrest with cardiogenic shock," he said.​

• Abiomed stock was down approximately 10% in morning trading Monday.

Dive Insight:

The serious signals of harm related to Abiomed's pump system for patients with right-sided heart failure are already causing dissension in the scientific community.

The first of two studies study showed use of a mechanical circulatory support (MCS) device like Impella may be associated with higher rates of adverse events compared to IABP in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (AMI-CS) undergoing percutaneous intervention. Published in the AHA journal Circulation, it included data from 48,306 patients undergoing PCI with MCS for a variety of indications at more than 400 hospitals between 2004 and 2016.

A second study analyzed 28,304 AMI-CS patients with a mean age of 65 years and found hospitals with higher rates of Impella use saw more adverse outcomes and had greater hospital costs.

The data for Impella in cardiogenic shock patients are welcome news following a setback in February for Abiomed's pump system  

"These data underscore the need for defining the appropriate use of MCS in patients undergoing PCI with appropriately powered prospective randomized controlled trials," Amit Amin of the Washington University School of Medicine in St. Louis, Missouri, said. Amin was one of the authors of the study published in Circulation.

"It adds to a healthy debate around this," Jefferies analyst Raj Denhoy told MedTech Dive on Monday. But, he said, there's reason to be cautious in interpreting the data because the studies aren't randomized and Abiomed has amassed a lot of data over the years showing opposite results.

The negative headlines aren't likely to help Abiomed encourage more doctors to adopt the device as the company tries to move from a subset of early adopters to a wider set of users. 

Abiomed's growth has been slowing lately, too. "Over the last three quarters, they've not been able to accelerate growth," Denhoy said.

The bad headlines aren't the first for Impella this year. In February, post-approval study data for Impella RP showed less than 20% of participants met the primary survival endpoint, compared to 70% in the clinical trial that won approval for the Impella RP. The results prompted FDA to alert cardiologists to the issue and advise them to weigh the patient selection criteria before using the device.