One of the most common forms of acquired valvular heart disease in the industrialized world is aortic stenosis. This progressive cardiac valve disorder is associated with substantial illness and death, seeing about a 50 percent mortality rate after two years once heart failure develops.
Aortic stenosis is mostly seen in patients in their 70s and 80s, typically after a long asymptomatic period followed by rapid progression once symptoms develop – generally the classic triad of syncope, angina and heart failure.
But there is hope. An effective and proven treatment for severe aortic stenosis is surgical aortic valve replacement, known as SAVR, which results in a striking improvement in patient outcomes. Since aortic stenosis primarily affects the elderly, many patients may be compromised by several chronic conditions, or they may be too old or frail to undergo this lifesaving surgical treatment. However, an alternative for these patients with severe aortic stenosis is transcatheter aortic valve replacement, or TAVR, a viable minimally invasive procedure.
Clinical trials have established the safety and effectiveness of TAVR with improved mortality and quality of life compared to medical therapy in “extreme risk” or inoperable patients with severe aortic stenosis. While these early studies demonstrated higher rates of stroke, vascular complications and pacemaker implantations with TAVR as compared with SAVR, these risks have continued to decrease as the devices have improved.
Two TAVR prostheses are currently approved for high- and extreme-risk patients in the United States: the balloon-expandable Edwards SAPIEN prosthesis and the self-expanding Medtronic CoreValve prosthesis. Early analyses have suggested relative cost-effectiveness for TAVR, particularly for the transfemoral approach (through the leg), compared to SAVR. Ongoing clinical trials are evaluating newer versions of approved valve prostheses, including fully retrievable and repositionable valves, and broader applications of TAVR to lower-risk patients and those with chronic conditions that were excluded from early clinical trials.
Future goals would be to reduce short- and long-term complications, improve device durability, and explore the applicability of TAVR to a broader range of the aortic stenosis patients so that TAVR might one day replace SAVR as the treatment of choice for all patients with severe aortic stenosis.
Dr. Matthews Chacko, assistant professor of medicine in the Division of Cardiology, Interventional Cardiology and CCU Faculty, at Johns Hopkins Hospital, will speak at the Cardiac Symposium on Thursday.