Transcatheter Aortic Valve Replacement--TAVR

Minimally Invasive Treatment for Aortic Stenosis

Heart Valves and Chambers
The Human Heart. Image: © ADAM

Aortic stenosis is a common heart condition that typically develops and increases with age. The aortic valve is one of four heart valves in the human heart, and can be seriously damaged by calcification.   This is a potentially serious condition that affects the moving parts of the valve and makes it less efficient. 

In the past, the primary treatment for severe aortic stenosis was open heart surgery where the valve was repaired  or a valve made from tissue or artificial material would be used to replace the damaged aortic valve.

  Today, there is a new and less invasive option called Transcatheter Aortic Valve Replacement (TAVR) that may be an option for patients who cannot tolerate the traditional open heart method of surgically repairing or replacing the aortic valve. 

What Does the Aortic Valve Do?

To best understand aortic valve replacement, it is important to understand what the aortic valve does.  The aortic valve is located between the left ventricle and the aorta, and helps control the flow of blood from the heart, into the aorta and to the rest of the body. A healthy aortic valve prevents blood from leaving the heart too soon, opening only when it is time for blood to move out of the left ventricle and into the aorta.  When the aortic valve is damaged and becomes narrowed, the condition is called aortic stenosis and can be very serious, as the flow of blood is no longer well controlled or efficient.

Signs of Aortic Stenosis

When the aortic valve becomes calcified, it no longer works properly, and the heart has to work harder to pump blood to the body.

  Some patients with aortic stenosis experience syncope, or episodes of fainting.  They may also experience chest pain, and in severe cases, the valve problem can lead to the development of another severe condition, called congestive heart failure. 

Fatigue and intolerance of exercise are some of the early symptoms of aortic stenosis, but in severe cases patients can be so weak that they experience an inability to walk more than a few feet.

  The condition can become so severe that it is life-limiting or life-threatening if left untreated, leading to the need for repair or replacement of the valve. 

Who Is a Candidate For TAVR Surgery

For the sickest aortic stenosis patients--who are often the patients with the greatest need for a heart valve that works properly--the open heart procedure may be deemed too risky.  Surgery is very stressful for the body, and some patients cannot tolerate that level of physical stress, making the risks of open heart surgery outweigh the potential rewards.  For the patients who are deemed too sick to tolerate surgery, or those who present a high level of surgical risk, the TAVR procedure may be an appropriate alternative.

TAVR Procedure

For high risk aortic stenosis patients, TAVR surgery may be an option that provides an aortic valve repair without the physical stress of open heart surgery, cardiopulmonary bypass and general anesthesia.  The procedure is performed percutaneously, meaning that the “surgery” is performed by inserting instruments into the femoral artery through a small incision and gently advancing through the blood vessels until the aortic valve is reached.

Patients who have had a heart catheterization will find the minimally invasive valve replacement procedure to be similar.   

For the TAVR procedure, the artificial valve is bundled into a tiny package that is small enough to be moved through the blood vessel along with the instruments. When in place, the valve replacement is deployed, opening to its full size.  Once the TAVR is in place, it replaces the damaged natural aortic valve and controls the release of blood from the heart.

Risks of TAVR

The risks of TAVR surgery are serious and should be discussed with your physician before the procedure.  The risks of TAVR are similar to the risks of open heart surgery to repair or replace an aortic valve, and include the risk of stroke, blood clots, bleeding, injury to the heart in addition to the risks of anesthesia.  

When comparing patients who had an open heart repair of aortic stenosis with patients who had the TAVR procedure, the TAVR patients have a greater risk of needing a pacemaker in the year following the procedure, but they also have a slightly lower risk of bleeding and death in the year following surgery.

The TAVR procedure is a new one, and as such, extensive long term research is not available at this time in the United States.  What research is available, however, indicates that high risk patients fare somewhat better with the minimally invasive procedure than with open heart repair of the valve.  

After TAVR

It is important to remember that the TAVR procedure is life-improving, but does not guarantee a total recovery from heart disease.  Most patients experience a notable improvement in quality of life with the repair of the aortic valve, but there may be lasting damage to the heart muscle due to the faulty valve or other coexisting heart conditions.  

Sources:

Transcatheter Aortic-Valve Replacement with a Self-Expanding Prosthesis. New England Journal of Medicine. Accessed March 2014.

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