Transcatheter Aortic Valve Replacement: Comprehensive Review and Present Status

Aortic stenosis is the most common valvular heart disease in the developed world. About 7% of the population over age 65 years suffers from degenerative aortic stenosis. The prognosis of patients with symptomatic severe aortic stenosis is dismal without valve replacement. Even though the American College of Cardiology recommends aortic valve replacement to treat this condition as a class I recommendation, approximately one third of these patients over the age of 75 years are not referred for surgery. Typically, this is from concern about prohibitive surgical risk associated with patient frailty, comorbidities, age, and severe left ventricular dysfunction. The advent in France of transcatheter aortic valve replacement has raised the hope in the United States for an alternative, less invasive treatment for aortic stenosis. Two recent trials-the Placement of AoRTic TraNscathetER Valve Trial Edwards SAPIEN Transcatheter Heart Valve (Partner) and the CoreValve US Pivotal-have established transcatheter aortic valve replacement as the preferred approach in patients who are at high or prohibitive surgical risk. The more recently published Partner 2 trial has shown the feasibility of transcatheter aortic valve replacement in intermediate-surgical-risk patients as well. With a profile that promises easier use and better valve performance and delivery, newer-generation valves have shown their potential for further improvement in safety profile and overall outcomes. We review the history and status of this topic.