There has been a flurry of news recently about a procedure called trans-catheter aortic valve replacement (TAVR) for the treatment of the common heart condition aortic stenosis (AS). You may even know people who have had this procedure performed.
What exactly is TAVR? And what's all the excitement about?
What is aortic stenosis?
First, it's important to understand the condition that TAVR is designed to treat, aortic stenosis. The aortic valve is the last structure of the heart through which blood passes before entering the aorta and circulating throughout the body. The aortic valve has three flaps, called leaflets, that open and close. When working normally, the aortic valve opens to allow blood to pass from the heart into the aorta, then closes to prevent blood from flowing back into the heart.
Over time, calcium deposits can develop on the leaflets of the valve, making it more difficult for the valve to open. This puts additional strain on the heart, which can lead to symptoms such as shortness of breath, lightheadedness, or chest pain with exertion. In severe cases, AS can lead to weakening of the heart muscle. If left untreated, the condition can be fatal.
Open heart surgery: Traditional treatment of aortic stenosis
Once AS is diagnosed and symptoms are present, it needs to be treated. The historical gold standard for treatment of AS has been open-heart surgery with surgical aortic valve replacement (SAVR).
Open heart surgery is a major operation in which the surgeon opens the chest to access the heart. During open-heart surgery the heart is stopped, and blood is bypassed through a heart-lung machine. With SAVR, the diseased valve is removed and a new artificial valve is sewn into place.
SAVR has had good outcomes in patients who are suitable candidates for surgery. However, SAVR does have a long recovery period that generally requires five to seven days of hospitalization after surgery, and upwards of six weeks to make a full recovery. Also, there are many patients who require aortic valve replacement but have too many other medical conditions that make them unsuitable candidates for SAVR.
TAVR: A catheter-based treatment for aortic stenosis
TAVR is performed by placing a catheter in the femoral artery, the large blood vessel in the groin. A new heart valve mounted on another catheter is threaded through the initial catheter in the blood vessel and across the diseased aortic valve. The new valve is deployed by pushing the old valve leaflets to the side. The new valve leaflets start to function immediately.
In most cases, the procedure lasts 90 minutes and is performed under sedative medications without general anesthesia. Many patients are able to be discharged the following day and are usually back to normal activity within a week.
Benefits and risks of TAVR
The initial clinical trials of TAVR, begun in 2007, evaluated TAVR in patients who were too ill to be considered for SAVR. These trials showed benefit at extending quality and length of life in patients with severe AS. Since that time, trials have been performed comparing TAVR to SAVR in patients who are considered high risk and intermediate risk for traditional SAVR. In each of these studies, TAVR was shown to be no worse or even better than SAVR. Because of the quick recovery with TAVR, it soon became the standard of care for intermediate and high surgical risk patients with AS.
The recent news about TAVR concerns clinical trials conducted on the healthiest patients; that is, patients who are considered low-risk surgical candidates. The PARTNER 3 Trial and the CoreValve Low-Risk Trial were presented at the recent American College of Cardiology Meetings in March 2019. Both trials showed significant benefits of TAVR compared to SAVR, including reduced rates of death, stroke, and repeat hospitalizations. It is expected that TAVR in low-risk patients will gain FDA approval in the near future. When this occurs, TAVR will be the standard of care or all patients with AS.
While TAVR has major benefits, there are certainly risks involved, as there are for any major heart procedure. These risks may include heart attack, stroke, bleeding, and need for emergency surgery, but these risks are low. There is also potential damage to the electrical system of the heart that may result in the need for the placement of a permanent pacemaker.
Is TAVR right for you?
As appealing as TAVR may sound if you need your aortic valve replaced, it may not be suitable for everyone. For example, some people have heart valve anatomy that may make SAVR a better option for them.
If you need your aortic valve replaced, it is important to be evaluated by a heart team that includes your clinical cardiologist, an interventional cardiologist, and a cardiac surgeon. The heart team will evaluate you and review all of your relevant medical information. They will provide treatment options and will discuss the risks and benefits of the options with you.
Follow me on Twitter