Impella Heart Pump – Necessity and Applications

January 05 05:43 2022 by admin Print This Article

The Impella Heart Pump is an external device that is temporarily introduced into the heart, to maintain healthy blood-flow during a high-risk, protected, Percutaneous Coronary Intervention (PCI). It is also used when there is a Myocardial Infarction (heart attack) induced Cardiogenic Shock. We will cover Cardiogenic Shock in a separate article. To understand why the Impella Heart Pump is required, we need to know a little about PCIs.

What is a PCI

As the name implies, Percutaneous Coronary Interventions is a procedure (intervention) in which an external device or mechanism is introduced from under the skin (percutaneous) in order to resolve one or more issues in the (coronary) arteries of the heart. They help restore blood flow to the heart muscle, reducing the risk of mortality and improving outcomes from the procedure.

Balloon Angioplasty with Stenting is one of the most high-profile and well-known PCI. But there are several others in vogue today:

• Cardioversion: A procedure to correct rapid/irregular heart rhythm
• Catheter Ablation: A procedure to correct abnormal electrical pathways in the heart
• Coronary Angioplasty: Widening blocked arteries using an inflated balloon

• Coronary Stent Placement: Inserting a metal coil called stent after blockage is cleared
• Directional Coronary Atherectomy: Involves shaving some of the plaque in an artery
• Doppler Flow Wire: A procedure used to measure blood flow before an intervention
• Implantable Cardiac Defibrillator: To monitor heart function and treat serious arrhythmias
• Intra-Aortic Balloon Pump (IABP): A precursor to the Impella heart pump
• Pacemaker: An electrical device to stimulate heartbeat and prevent slow heart rhythms
• Pericardiocentesis: Removing fluid around the heart muscle for analysis in a lab
• Percutaneous Transluminal Angioplasty: Restores normal blood flow to narrowed arteries
• Renal Artery Stenting: Similar to coronary artery stenting but in the kidneys
• Rotational Coronary Atherectomy: Another procedure to widen narrowed arteries
• Transluminal Extraction Catheterization: To extract blood clots
• Temporary Wire Placement: Before a pacemaker is inserted

Challenges faced during a PCI

Most patients can safely go through a PCI without the support of an external or introduced heart pump. However, some patients who have one or more critical blockages in the coronary arteries, or weak heart muscles, may require additional support. Without this support, the risk of mortality increases.

That is where the Impella Heart Pump comes into the picture. This pump is used to support such patients. It is also used for patients experiencing a heart attack and cardiogenic shock as a result. The pump is used then for additional support, so that the heart can now rest and heal quickly.

How the Impella Heart Pump works

The Impella Heart Pump is popular for its sleek design and ease of use. The sleek design minimizes discomfort to the patient and accidental damage to the arteries during insertion. Every model of the device produced by any manufacturer must go through an FDA-approval.

It consists of a short and thin metal tube that is bent at an angle of 30 degrees approximately. Firstly, an incision is made in the upper thigh. The metal tube is inserted into a catheter, and the catheter is gently threaded into the femoral artery all the way to the heart. In the heart, the lower hook-shaped opening called the input, is placed in the left ventricle and the upper, vertical opening, called the output, is placed in the aorta.

During a PCI procedure, the pump is able to achieve a blood-flow or pumping rate of 2.5 to 5 liters per minute depending on the case. Once the procedure is over, and the pump no longer required, its pulled back into the catheter and out of the body. In some patients, the pump is left in place for 4-5 days to ensure stability of heart function.

Although a minimally-invasive procedure, some patients may be hospitalized for a day or two, while most patients are discharged after a couple of hours.

Benefits / Advantages

The Impella Heart Pump can be seen as an improvement or a better alternative to the Intra-Aortic Balloon Pump (IABP). It brings many advantages to both the patient and the physician.

• Supports Your Heart Function: In a protected PCI, there must be a healthy blood-flow (perfusion) to all the organs to prevent the risk of hypoxia (reduced oxygen levels due to reduced blood flow) which is a risk for organ failure. The pump achieves this precisely.
• Better Quality of Life, post-procedure: In one RCT (randomized controlled trial), 8 out of 10 patients who underwent a PCI with Impella Heart Pump, experienced fewer and less-frequent heart-failure symptoms as well as an improvement in heart function.
• Reduces Heart Failure Symptoms: Typical symptoms of heart-failure such as fatigue, shortness of breath (dyspnea), swelling, and coughing., were fewer in Impella-treated patients.
• Fewer Days of Hospitalization: Compared to traditional treatments such as the IABP
• Fewer follow-up visits: Compared to IABP, Impella-treated patients have fewer heart-related issues post the procedure.
• Fewer Adverse Events: Over a period of 3 months after the procedure, Impella-treated patients showed fewer instances of death, heart attack and stroke compared to other methods of heart support.

 Other Applications

• Cardiogenic shock: A cardiogenic shock can be induced by a Myocardial Infarction (heart attack). Blood flow starts dropping drastically, leading to hypoxia (reduced oxygen levels) which can lead to organ failure. Impella is used for such patients to restore blood flow.

• High-risk, non-emergent PCI: Some patients with heart conditions such as multivessel heart disease, left-main-coronary artery disease and severely reduced ventricular function may not be suitable for a bypass or incisional surgery. A high-risk PCI such as balloon angioplasty or stenting is the only option. But this too comes with the risk of transient ischemia, leading to hemodynamic collapse and severe dysthymias. An Impella reduces this risk.
• Ablation of Ventricular Tachycardia (VT): Most patients with a structural heart disease are prescribed a VT ablation. During this procedure, hemodynamic (blood flow) support is provided by Impella.
• Bridge to permanent LVAD placement: Left Ventricular Assist Device (LVAD) is a heart-pump surgically implanted in patients with end-stage heart failure. During the procedure of implanting, hemodyamic support is provided by Impella.
• High-risk Valvuloplasty: Procedures for valve repair or valve replacement, such as transcatheter aortic replacement and aortic valvuloplasty, can be high-risk. Hemodynamic support during the procedure is provided by Impella.

Limitations / Complications

• Thrombus or blood clots: A blood clot present in the left ventricle may get sucked into the Impella and the aorta and from there, travel through the body, which brings several risks.
• Vascular access-site issues: The size of the sheath used to push the catheter can be an issue. It can cause hematoma (bruising), bleeding and injury to blood vessels.

Future Directions and Outlook

In spite of the complications or risks, Impella Heart Pumps are becoming more popular by the day. More randomized controlled trials will be conducted to assess the efficacy of the pump in various coronary situations. Needless to say, the design of these pumps will also evolve, to overcome limitations. For example, concerns around sheath size have been addressed with the latest pumps coming in smaller sheath sizes. Rest assured, these pumps offer a ray of hope to heart patients who undergo various procedures, by reducing risk, improving outcomes and ensuring better quality-of-life post-procedure.

Reviewed by Dr Suresh S Venkita, Group Medical Director, Kauvery Hospitals

Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

Chennai – 044 4000 6000 • Trichy – Cantonment – 0431 4077777 • Trichy – Heartcity – 0431 4003500 • Trichy – Tennur – 0431 4022555 • Hosur – 04344 272727 • Salem – 0427 2677777 • Tirunelveli – 0462 4006000 • Bengaluru – 080 6801 6801