Transcatheter Aortic Valve Replacement (TAVR)
Valve replacement for inoperable patients
Oregon Heart & Vascular Institute is one of three facilities in the state approved to offer transcatheter aortic valve replacement (TAVR) to appropriate patients with aortic valve stenosis who are not candidates for open surgery to replace their native aortic valve.
Until recently, aortic valve replacement via open-heart surgery was the only effective treatment available to aortic stenosis patients, many of whom were considered inoperable due to co-existing medical conditions. As a result, as many as 40 percent of patients with severe aortic stenosis did not have access to aortic valve replacement. TAVR is changing that.
"TAVR is an innovative new procedure that can offer life-prolonging therapy to people who were not considered candidates in the past," said interventional cardiologist Dennis Gory, MD, Medical Director for the Comprehensive Valve Program at Sacred Heart Medical Center's Oregon Heart & Vascular Institute.
TAVR enables percutaneous replacement of the diseased aortic valve through a minimally invasive transfemoral approach. The technology makes treatment available for a broader range of patients, including those considered too frail or high-risk for traditional heart surgery. The Edwards balloon-expandable valve consists of a stainless steel frame and three bovine pericardial tissue leaflets.
Dr. Gory and interventional cardiologist Sudeshna Banerjee, MD, head up a multi-disciplinary team of cardiothoracic and vascular surgeons specially trained to perform TAVR. Dr. Banerjee performed TAVR procedures during her training at Washington University in St. Louis as part of the original PARTNER trial.
Patients managed medically had a mortality exceeding 50 percent at one year. The PARTNER trials showed a significant 20 percent absolute reduction in mortality with TAVR at one year, and a marked reduction at two years. In appropriate patients, TAVR offers superior survival rate, reduction in symptoms and restoration of quality of life, improvement in hemodynamics, and sustained valve performance. TAVR patients experienced a higher incidence of stroke and major vascular complications and bleeding than standard therapy patients, so careful selection is necessary.
The valve may be placed in symptomatic patients with echo criteria for severe aortic stenosis: AVA<1cm2, and a mean gradient of 40 mmHg or more, or a velocity of 4m/sec or more.
The valve is currently approved for inoperable patients only. Two cardiovascular surgeons must determine that the patient is inoperable and specify the reasons for the determination.
Presently, the delivery system for the valve is only available for the transfemoral approach.
The following evaluations are generally performed before valve replacement. These tests may be performed at Sacred Heart Medical Center or at another facility:
- Transthoracic echo with assessment of the aortic valve PFTs with DLCO and ABG
- Carotid duplex
- Coronary/graft angiography. Right heart catheterization is helpful but not mandatory. Formal invasive valve calculation is not required unless there is concern regarding the echo-derived data.
- CT angiogram of entire aorta. This is used to determine deliverability of the device via the femoral route. In addition, several issues that may make the patient inoperable can be detected by this study (e.g., porcelain aorta). Note: In general placement of the valve requires 7 to 8 mm vessels in the iliofemoral circulation.
Once all the data is obtained and the assessment complete, all patients are presented to Edwards Lifesciences, maker of the valve, before valve implantation occurs.