Left ventricular support by catheter-mounted axial flow pump reduces infarct size

Area of Science:

• Cardiology
• Cardiovascular Surgery
• Biomedical Engineering

Background:

• The Impella device is a small rotary blood pump designed for left ventricular unloading.
• It is introduced via the femoral artery, offering a less invasive approach.

Purpose of the Study:

• To investigate the impact of a catheter-mounted microaxial blood pump on myocardial infarct size.
• To assess the pump's effects on hemodynamics, oxygen consumption, and myocardial flow.

Main Methods:

• Myocardial infarction was induced in 26 sheep by coronary artery occlusion.
• Animals were divided into four groups: no support, full support, reperfusion support only, and partial reperfusion support.
• Infarct size, hemodynamics, myocardial oxygen consumption, and myocardial flow were analyzed.

Main Results:

• Pump support significantly reduced infarct size across all supported groups compared to the control group (p = 0.00001).
• The pump increased blood pressure and decreased left ventricular end-diastolic pressure.
• Myocardial oxygen consumption was significantly reduced, correlating strongly with infarct size reduction (r = 0.9).

Conclusions:

• Catheter-mounted microaxial blood pump support effectively reduces myocardial oxygen consumption during ischemia and reperfusion.
• This reduction in oxygen demand leads to a significant decrease in myocardial infarct size.
• The degree of left ventricular unloading during reperfusion correlates with the observed reduction in infarct size.