Valvular heart disease is a common malady, affecting millions of people in the United States and world wide.1 The incidence of degenerative and functional valvular disease is rising with the ageing population and the increase in patients with congestive heart failure.2 Treatment requires surgery, as medical treatment has not provided significant advantages for these patients. Although surgical valve repair or replacement has been well established as a safe and effective alternative,3 the procedure is invasive and still carries a significant morbidity and mortality risk, especially among patients with serious comorbidities or very elderly patients. The introduction of transcatheter valve therapies is intended to reduce the morbidity and mortality of mechanical valve intervention for patients at higher risk. This review examines the new and emerging transcatheter therapies for acquired aortic and mitral valve disease.

The design and implementation of transcatheter valve therapies differ greatly based on the valve needing treatment and the approach utilised. The dominant design of valves developed for the aortic and pulmonic positions are stent-based bioprosthetic valves, advanced over a balloon and expanded within the original valve, a conduit, or deployed within a self-expanding stent device. Approaches to the mitral position are more varied in terms of device designs, including direct leaflet modification (clip or suture), indirect annuloplasty using the coronary sinus, direct annuloplasty and ventricular geometric modification.

HISTORY

The use of a high-risk target population for the development of transcatheter technology began in the 1980s with the use of percutaneous aortic balloon valvuloplasty (PABV) for high-risk surgical patients.4 5 Initial enthusiasm for PABV waned as its early haemodynamic benefits were attenuated by subsequent restenosis. The momentum for percutaneous treatment of high-risk patients and the technical lessons learnt from PABV were not lost, however, as coincident with the refinement of balloon valvuloplasty techniques was the …