The Impella procedure is a form of temporary cardiac assistance used to manage patients with failing heart function. This intervention involves a micro-sized, catheter-based pump that supports the heart’s pumping action. It is typically employed to maintain blood circulation and allow the heart muscle to rest and recover during high-risk cardiac procedures or when the heart is too weak to sustain the body’s needs. Providing mechanical assist, the Impella system buys time for the medical team to treat the underlying cause of the heart failure.
Defining the Impella System
The Impella device is a miniature, catheter-based heart pump designed to provide continuous blood flow support. It is a percutaneous ventricular assist device (pVAD) mounted on a flexible catheter, allowing it to be threaded through blood vessels to reach the heart. The core technology is a microaxial flow pump, which rotates at high speeds to move blood forward.
For the common left-sided Impella, the device is positioned across the aortic valve. The pump’s inlet sits inside the left ventricle, while the outlet is located in the ascending aorta. Once activated, the pump draws blood from the left ventricle and expels it into the aorta, effectively bypassing the failing native ventricular function. This action unloads the left ventricle, reducing its workload and oxygen demand while ensuring the body receives sufficient blood flow, with models providing up to 5.0 liters per minute of cardiac output support.
Conditions Requiring Impella Support
Impella is reserved for patients in two primary clinical scenarios requiring immediate cardiac support. The first indication is High-Risk Percutaneous Coronary Intervention (HR-PCI), often called “Protected PCI.” These are complex stent placement procedures in patients with severe blockages and poor heart function. The procedure risks causing a temporary drop in blood pressure and heart function. Prophylactic placement of the pump before the procedure ensures stable circulation throughout the intervention, protecting vital organs.
The second major indication is treating Cardiogenic Shock, a life-threatening condition where the heart is too weak to pump enough blood, often following a massive heart attack. The Impella device provides immediate mechanical support to improve systemic blood flow and organ perfusion. This temporary support can serve as a “bridge to recovery,” allowing the heart muscle to rest and potentially regain strength. Alternatively, it acts as a “bridge to decision,” stabilizing the patient while the medical team determines if a more permanent solution, like a heart transplant, is necessary.
The Insertion and Removal Process
The Impella procedure is minimally invasive and performed in a cardiac catheterization laboratory. Access is typically gained through a large artery, most commonly the femoral artery in the groin. Specialized catheters and wires are used to navigate the device through the blood vessels toward the heart.
The physician uses fluoroscopy to guide the pump’s catheter retrograde up the descending aorta and across the aortic arch. The pump motor is positioned so its inlet is within the left ventricle and its outlet sits in the ascending aorta. Precise positioning across the aortic valve is verified using imaging and pressure waveform monitoring to ensure optimal function.
When the patient’s heart function has recovered, the Impella device is removed, usually in the catheterization lab. Removal involves turning the pump off, pulling the catheter back across the aortic valve, and carefully withdrawing the assembly from the artery. Due to the large access sheath size, specialized closure techniques, like surgical repair or dedicated vascular closure devices, are utilized to seal the entry point and manage bleeding.
Potential Outcomes and Management
Following placement, patient management focuses on continuous monitoring and maintaining the device’s function while the heart heals. Systemic anticoagulation therapy, typically with intravenous unfractionated heparin, is mandatory to prevent blood clots from forming on the pump components. A specialized purge solution, often containing heparin, is also continuously delivered through the catheter to flush the motor and bearings, preventing device failure.
The Impella procedure carries inherent risks as a high-acuity intervention for critically ill patients. Potential complications include bleeding at the large insertion site, which is exacerbated by the required anticoagulation. Other risks involve damage to the blood vessels, stroke from micro-emboli, and hemolysis (destruction of red blood cells) due to the high-speed rotation of the pump. Close monitoring of blood counts and the pump’s performance is constant throughout the support period.