New results from a prospective, randomized, multi-center trial of the Impella CP heart pump (Abiomed) versus intra-aortic balloon (IAB) counterpulsation in patients with cardiogenic shock demonstrated no improvement in mortality with the Impella CP device and significantly more bleeding and hemolysis complications. The data were recently presented at the 28th Annual Transcatheter Cardiovascular Therapeutics (TCT) Scientific Symposium in a “Featured Clinical Research: Presentations to the Editors of the European Heart Journal” sub-session. The trial was designed and sponsored by the Academic Medical Center, Amsterdam.
The study presented at TCT 2016 was underpowered but did include an interim analysis to expand the number of patients enrolled. This turned out to be unnecessary because there was no signal that a larger trial would have yielded a different result. This study is the third randomized trial that has failed to demonstrate an improvement in outcomes with Impella over IABPs. In 2008, the ISAR-SHOCK trial showed that hemodynamic support increased at 30 minutes but was similar at all other time points, and 30-day mortality was the same in the Impella and IABP study groups but complication rates were higher with the Impella device. In 2010, Abiomed stopped its high-risk PCI PROTECT II trial after determining the study could not reach its primary endpoint of a difference in 30-day adverse events.
IAB pumps (IABPs) are circulatory assist devices that are inserted into the aorta and counterpulsate to help the heart pump blood in patients in need of cardiac support. Based on extensive literature supporting the hemodynamic effects and safety and effectiveness of IABPs, the U.S. Food and Drug Administration (FDA) has cleared them for use in patients with acute coronary syndrome (any condition in which blood flow to the heart is suddenly reduced or blocked), patients undergoing cardiac and non-cardiac surgery, and patients experiencing complications of heart failure. The FDA clearance for these indications was based on results from a comprehensive literature review of IAB therapies, which demonstrated low overall rates of complications with the device, despite the fact that patients in whom IABs were implanted had more severe comorbidities and underlying illnesses than patients without the device. Additionally, the literature shows trends to less device-related mortality over time, as balloon catheter sizes have decreased and procedural techniques have improved in recent years.