Impella Pump Takes Positive Turn in Cardiogenic Shock Study

Patrice Wendling

March 27, 2017

WASHINGTON, DC — New research shows the Impella (Abiomed) ventricular assist device continues to be used in only about 5% of US patients in acute-MI cardiogenic shock (AMI-CGS), and when used, there is a wide institutional variation in outcomes.

Prospective, systematic adoption of best practices, however, "markedly improved survival and native heart recovery," lead author Dr William O'Neill (Henry Ford Hospital, Detroit, MI) said at the American College of Cardiology 2017 Scientific Sessions[1].

For example, when the Impella device was inserted prior to PCI— before rather than after patients had failed intra-aortic balloon pumps (IABPs) or inotropes—survival increased from 52% to 59% in the Impella Quality (IQ) database and from 41% to 65% in the global cVAD registry.

O'Neill said something as simple as using a Swan-Ganz catheter to monitor hemodynamics also improved survival from 49% to 63% in the IQ database and from 68% to 76% in the cVAD registry.

"In other therapies in the ICU, Swan-Ganz catheters have not been very effective, but in this particular incidence it looks like it significantly increases survival," he noted during the late-breaking clinical-research session.

O'Neill described AMI-CGS as a "massive problem," with multiple registries showing that "still today 50% mortality occurs in patients that come into a US hospital in acute MI shock" and "this has not changed at all since 1987." Further, the number of AMI-CGS cases is actually increasing from an estimated 74,355 in 2009 to 89,923 in 2016.

In prior studies, however, the Impella heart pump has shown no added benefit in cardiogenic shock over that provided by the less costly balloon pumps.

Commenting to heartwire from Medscape, session cochair Dr Douglas L Mann (Washington University School of Medicine, St Louis) said, "I don't think we've wrapped our heads around how useful the device is, and I think there are some economic pressures in terms of reimbursement on the device. But for the cardiogenic-shock indication, it is much more useful than the balloon pumps."

Observational Data

The study included observational data from 15,259 patients (mean age 63.6 years; 73% male) treated at 1010 US Impella centers from 2009 to 2017 in Abiomed's IQ database and from 2704 patients (mean age 66.3 years; 76% male) treated from 2009 to 2016 in the global cVAD registry. The mean duration of device support in the two groups was 3.78 days and 1.63 days, respectively.

The Impella pump was used in 1% of cardiogenic-shock patients in 2010 and in 6% in 2016, when it gained premarket approval for use in cardiogenic shock.

Among 791 centers that used the Impella device more than four times, mean survival was 30% in the bottom 20% of sites and 76% in the top 20% sites with a higher volume of Impella utilization.

O'Neill noted that higher inotrope exposure has also been shown to be associated with increased mortality in AMI-CGS.

Pilot Study of Best Practices

He went on to provide a deeper dive into outcomes from a pilot study that prospectively enrolled 37 patients (mean age 63 years) from July 2016 to February 2017 at five Detroit-area hospitals that performed more than 10 AMI-CGS cases with Impella within the last calendar year. They also followed other best practices of placing the Impella device quickly (mean door-to-unloading time 82 minutes), supporting patients with Impella before PCI in 62%, and decreasing inotrope or vasopressor use in 80%.

Cardiac power output improved from 0.56 W pre-Impella to 0.96 W post-Impella (P<0.001).

The percentage of patients surviving to explant improved from 51% to 89%.

In all, 84% of patients survived to discharge, with native heart recovery achieved in 100% of the 31 survivors.

Panelist Dr Adrian F Hernandez (Duke Clinical Research Institute, Durham, NC) told heartwire , "Once people start seeing this data, they'll start acting more aggressively to identify shock and treat it appropriately."

He added, "There are limitations when you're looking at observational data, but again, if we're talking about trying to improve quality of care and delivery of care, this certainly shows that centers that are doing this more often will benefit. We need people to recognize this more and use the best tools there are. Patients' lives are at stake."


O'Neill reported consultant fees/honoraria from Abbott, Boston Scientific, Edwards Lifesciences, and Medtronic; and serving as an officer, director, trustee, or in another fiduciary role for Neovasc. Mann reported no relevant financial relationships. Hernandez reported consultant fees/honoraria from Amgen, Bayer, Boehringer Ingelheim, Boston Scientific, Gilead, Merck, Novartis, Pfizer, Pluristem Therapeutics, and Sensible; and research grants from Abbott Evalve, Aires Pharmaceuticals, Amgen, Amylin, AstraZeneca, Bristol-Myers Squibb, Genentech, GlaxoSmithKline, Merck, Novartis, Pfizer, Portola, Roche, and Scios.

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