October 1, 2010 – The most recent clinical data from USpella, a U.S. multicenter, observational registry of patients who received percutaneous cardiac support from the Impella 2.5 device, was released at TCT 2010 last week.
The Impella left ventricular assist device (VAD) is used in some of the sickest patients with compromised cardiac function. Registry data showed 90 percent of the survivors recovered native cardiac function and were discharged with their own hearts. Significant improvement was also seen in 49 percent of patients in New York Heart Association (NYHA) heart failure class, with a 61 percent reduction in NYHA Class IV patients.
Data from 24 U.S. and Canadian centers have contributed data for a total of 352 patients. The updated results were presented during an sessions by William O’Neill, M.D., University of Miami Miller School of Medicine, and Brijeshwar Maini, M.D., Pinnacle Health and Vascular Institute.
Key results after prophylactic Impella supported revascularization:
• Significant (17 percent) improvement of left ventricular ejection fraction
• Significant improvement (49 percent of patients) in NYHA class with 61 percent reduction in NYHA class four
• Significant (25 percent) reduction in implantable cardioverter defibrillator (ICD) target population, leading to potential cost savings
• More than half of the patients (54 percent) were turned down for cardiovascular bypass graft surgery (CABG), 59 percent of the patients had experienced a prior myocardial infarction (MI)
• Low mortality (3.9 percent) and major adverse cardiac events (MACE) event rate (8.2 percent) in patients, compared to high risk percutaneous coronary intervention (PCI) literature (Syed Al, et al. Cardiovascular Revasc Med 2010, 1191-7)
“This is not a cherry-picked group for this study, O’Neill said, pointing out the registry reflects real-world patient experience.
He said many of these patients had diabetes, peripheral vascular disease and heart failure.
Registry data has clarified one area of concern for the U.S. Food and Drug Administration (FDA), which was possible damage to the aortic valve where the Impella enters the heart. However, O’Neill said this is not an issue, with zero problems reported at 30 days.
Other registry data after emergent Impella support:
• Hemodynamic support with the Impella 2.5 (Cardiac Index, Cardiac Power Output, Wedge Pressure, Mean Arterial Pressure) significantly increased over the IAB in this study
• Impella improves Cardiac Power Output (CPO), the strongest correlate of in-hospital mortality (CPO increased from 0.5 +0.2 before Impella support to 1.0 + 0.2 after Impella support)
• Significant (19 percent) improvement of LVEF at discharge
• Significant reduction (59 percent) in mortality in the group that received Impella before PCI
• Ninety percent of the survivors recovered native cardiac function and were discharged with their own hearts
Use Before or After PCI?
To data the Impella has been used in the majority of cases after PCI, but O’Neill said an increasing number of patients are being placed on Impella support prior to PCI to increase perfusion. He attributes the increase to physicians becoming more comfortable with the device and faster set up times.
He pointed to acute myocardial infarction shock patients who have been placed on the device and lower mortality rates for those placed on support prior to PCI (mortality of 23 percent pre-PCI vs. 56 percent post-PCI).
“I think putting the device in before PCI is very important to myocardial salvage,” O’Neill said. “I think that should become a standard.”
John Lasala, M.D., Ph.D., Washington University School of Medicine, St. Louis, agreed the device offers myocardial protection in heart attack patients. “It can provide better support and provide perfusion even before PCI,” he said. “We are clearly improving collateral flow with the Impella.”
Impella vs. IABPs
The Impella is sometimes used as a bailout device after intra-aortic balloon pumps (IABPs) could not deliver enough hemodynamic support, O’Neill said. A randomized study is really needed to draw conclusions, he said, but pointed to Impella registry data so far has shown 20 percent of patients are placed on the device after IABPs.
“We know patients on a balloon pump who were not doing well did better when they were switched to Impella,” O’Neill said.
A comparison between Impella and IABPs is being conducted in the PROTECT II trial. It began two years ago and has recruited about 654 patients, which is about 60 percent of the planned enrollment. The trial is should to be completed by 2012.
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