Transcatheter Aortic Valve Replacement (TAVR)
by Dr. Steven Kernis
Aortic stenosis is a common condition which involves narrowing of the opening of the aortic valve. The aortic valve contains leaflets which act like a door and when it opens it allows blood to exit the heart and travel to the entire body outside of the lungs. The work that the heart must endure to pump blood across this restricted valve opening is greatly increased when aortic stenosis becomes severe. The only treatment for this condition is to replace the damaged aortic valve with a new one.
Unfortunately, a majority of patients with severe aortic stenosis in need of valve replacement surgery are at excessive or prohibitively high risk for conventional open-heart surgery. Multiple medical conditions, advanced age, and frailty can account for this elevated risk. Importantly, if left untreated, severe aortic stenosis can lead to heart failure and death.
Luckily, a new, far less invasive procedure called transcatheter aortic valve replacement (TAVR) has emerged for the treatment of severe, symptomatic aortic stenosis in patients with high- or prohibitive-surgical risk. This involves inserting a catheter containing a tissue valve inside a stent into the femoral artery and positioning it inside the diseased aortic valve. The stent valve is then deployed in a process akin to opening a stent inside a heart artery. The procedure is similar to a cardiac catheterization and it does not involve opening the chest, stopping the heart, or using a heart-lung bypass machine.
The TAVR procedure has been extensively studied for over 5 years and multiple large clinical studies have shown it to be equally safe and effective as compared with surgical aortic valve replacement. The PARTNER (Placement of Aortic Transcatheter Valve) Trial was the large, randomized clinical trial that tested the TAVR procedure. It was initiated in 2007 and the study outcomes were so positive that this study led to the FDA approval of the TAVR device for commercial use in 2011. In the Fall of 2012, the FDA expanded the indications of the procedure to include high risk patients in addition to the previously accepted prohibitive risk individuals from the year before. As compared with no replacement (i.e.: medical therapy), TAVR reduces the risk of dying by 50% within 1 year. In fact, there has never been a therapy (medical or interventional) in cardiovascular medicine to have this profound improvement in patient prognosis.
A minority of medical centers in the U.S. perform this groundbreaking technology. Lourdes Medical Center is just one of two hospitals in southern New Jersey which offers this procedure. Stringent prerequisites established by the medical community require that a hospital have a heart team consisting of very experienced, advanced multispecialty physicians to work together in evaluating and treating patients considered for and undergoing TAVR. The physician team performing the procedure is led by the interventional cardiologist and the cardiac surgeon. Additionally, there is a large supporting cast of physicians and non-physician medical personnel who participate closely in the management of these patients.
TAVR is another great example of the movement of medical procedural therapies towards a less invasive approach. Any interventional or surgical treatment that can be performed with equal or better success and safety is clearly attractive to people. It is anticipated that TAVR will be offered to less high risk individuals over the next few years.