The Emergence of Transcatheter Aortic Valve Replacement

Aortic valve stenosis (AVS) involves thickening and progressive immobility of the aortic valve. This restricts blood flow from the left ventricle to the aorta. AVS most frequently involves an anatomically normal three-leaflet aortic valve and is less frequently due to either a congenitally abnormal bicuspid aortic valve or to the late consequence of rheumatic fever. Since AVS predominantly afflicts the elderly, its prevalence is increasing. In fact, AVS currently ranks among the top five Medicare cardiac diagnoses. AVS is slowly progressive and has a long asymptomatic period. However, the prognosis turns grim once the cardinal triad of symptoms occur, including: Progressive shortness of breath. Anginal-like chest discomfort. Lightheaded or fainting spells. In such cases, the average survival without aortic valve replacement (AVR) is between 1 and 2 years. Improved Surgical Treatments for AVS Until recently, the only treatment for AVS has been surgical AVR. Unfortunately, the morbidity and mortality related to this open-heart surgery in elderly patients can be prohibitive and has prompted the development of less invasive non-surgical, catheter-based technologies to replace the aortic valve. Recently, the FDA has approved a new balloon-expandable stent-mounted bovine pericardial valve (SAPIEN, Edwards Life Sciences) for the treatment of symptomatic severe AVS in patients who are considered to be at either high or prohibitive risk for surgical AVR. The valve represents a significant advance in that it’s delivered via femoral arterial access and does not require cardiopulmonary bypass. “There is hope that TAVR will continue to emerge as a viable alternative to surgical AVR in patients at high surgical risk.” In the Placement of Aortic Transcatheter Valves (PARTNER) trial, transcatheter AVR (TAVR)...