DanGer Shock Study Evaluates Impella CP Heart Pump After Severe Heart Attacks

April 7, 2024—Findings from the DanGer Shock study showed that implantation of the Impella CP micro-axial flow pump (Abiomed, part of Johnson & Johnson MedTech) in the hours after a heart attack significantly increased the rate of survival at 6 months in patients with cardiogenic shock.

The study, which met its primary endpoint, suggests that by helping to restore the flow of oxygen-rich blood to the body, the Impella CP device can help to improve survival in these severe cases.

The DanGer Shock study was funded by the Danish Heart Foundation and Abiomed/Johnson & Johnson.

Jacob E. Møller, DMSc, presented the study results at ACC.24, the American College of Cardiology’s Annual Scientific Session held April 6-8 in Atlanta, Georgia. Simultaneously, the study was published online by Dr. Møller, et al in The New England Journal of Medicine.

Dr. Møller is a professor in the Department of Cardiology at the Odense University Hospital in Odense, Denmark, and a consultant at the cardiac intensive care unit of Copenhagen University Hospital Rigshospitalet in Copenhagen, Denmark.

“This is the first time in a very long time that we have a positive study for managing cardiogenic shock,” commented Dr. Møller in the ACC press release. “I think this will be a routine device that will be used in these desperately ill patients.”

The Impella CP is a small percutaneous pump placed within the heart’s left chamber, where it expels oxygenated blood from the left ventricle to the body with a flow rate of up to 3.5 liters per minute.

According to the ACC press release, the new DanGer Shock trial is the first trial powered to examine whether the use of micro-axial flow pumps can improve survival in ST-elevation myocardial infarctions (STEMI) that are complicated by cardiogenic shock. ACC noted that previous trials evaluating the potential benefits of this and other heart pumps for cardiogenic shock have had mixed results.

As summarized in the ACC press release, the trial enrolled 360 patients treated for STEMI with cardiogenic shock at 14 centers in Denmark, Germany, and the United Kingdom. Patients who had out-of-hospital cardiac arrest with coma and increased risk of brain damage were excluded from the trial. The investigators randomly assigned patients to receive standard care or standard care plus treatment with an Impella CP pump.

Patients in the study were randomized before, during, or up to 12 hours after receiving treatment in the cardiac catheterization laboratory, depending on when cardiogenic shock was diagnosed.

Among 355 patients who were included in the analysis, 58.5% of those who received standard care alone and 45.8% of those who received the Impella pump had died at 6 months after randomization. There was a 13 percentage point absolute reduction in the rate of death, the study’s primary endpoint, in favor of the heart pump.

In addition, the results showed a reduction in a composite endpoint of additional mechanical heart support, heart transplant, or death among patients who received the heart pump, but there was no difference between the two groups in the number of days out of the hospital.

“What was a surprise for us was that the benefit seems to persist beyond 30 days,” stated Dr. Møller in the press release. “It’s not only that we are saving lives, it looks like we are also saving myocardium so the patients keep surviving, and the survival curves continue to separate beyond the first 30 days.”

However, the results also showed significantly higher rates of complications among patients who received the heart pump, including bleeding, limb ischemia, renal replacement therapy and sepsis. Dr. Møller added, “It doesn’t come without a cost—we see significantly more serious complications in the Impella treated patients. Overall, we have more complications, but we also save lives.”

Dr. Møller advised that the study is not generalizable to all cases of cardiogenic shock as the trial was more selective than previous trials in identifying patients who were most likely to be able to benefit from the use of a heart pump, for example, by excluding those with a risk of brain damage. However, within this patient population, he said the results are likely translatable beyond northern Europe to large centers with the necessary expertise to employ the device.

Finally, subgroup analyses suggested that patients with very low blood pressure and those with lesions in more than one coronary artery may see a greater benefit from the Impella pump.

Dr. Møller advised that further studies are needed to assess the benefits in more diverse patient populations and to examine how the duration of mechanical support might affect the rate of severe complications and identify opportunities to further optimize practices to minimize complications, reported the ACC press release.