In the DanGer Shock trial, researchers found that utilizing a microaxial flow pump (Impella CP) alongside standard care resulted in decreased mortality rates compared to standard care alone for patients experiencing ST-elevation myocardial infarction (STEMI)-related cardiogenic shock. Lead author Jacob E. Møller, MD, PhD, highlighted this finding at the American College of Cardiology (ACC) Scientific Session 2024 and in the New England Journal of Medicine. However, the use of Impella CP was associated with increased adverse events.
The Impella CP, a compact percutaneous pump positioned within the left chamber of the heart, facilitates the expulsion of oxygenated blood from the left ventricle to the body with a flow rate of up to 3.5 liters per minute. Møller, a cardiology professor at Odense University Hospital in Denmark, emphasized that despite more complications, the use of Impella CP was linked to saving lives.
The trial randomly assigned patients with STEMI and cardiogenic shock to either receive Impella CP plus standard care or standard care alone. Results at 180 days showed a significant reduction in mortality among patients receiving Impella CP (45.8% vs 58.5% in the standard care group). Additionally, there was a decrease in the composite cardiac endpoint in the Impella CP group.
However, patients in the Impella CP group experienced more adverse events, including severe bleeding, limb ischemia, hemolysis, device failure, or worsening aortic regurgitation. Notably, more patients in the Impella CP group required renal replacement therapy, raising questions about the device's impact on renal function.
Møller emphasized caution in generalizing these findings to other causes of cardiogenic shock, highlighting the importance of patient selection. During discussions, experts underscored the need to mitigate adverse events associated with Impella CP use to further improve outcomes.
Dr. Sunil Rao, director of interventional cardiology at NYU Langone Health System, recognized the trial's significance despite being initially skeptical of Impella. He emphasized the importance of standardized protocols and best practices in reducing adverse events associated with Impella CP use.
Rao suggested strategies such as using ultrasound and micropuncture for femoral access and employing antegrade catheterization to maintain blood flow in the leg during device placement. He speculated that some adverse events may be linked to prolonged survival rather than the device itself.
In conclusion, while the trial demonstrated a reduction in mortality with Impella CP use, further investigation into mitigating adverse events is necessary. The study was supported by the Danish Heart Foundation and Abiomed/Johnson & Johnson, the manufacturer of Impella CP.