2 Indications and current treatments
2.1 The 2 main indications for aortic valve replacement are aortic stenosis and aortic regurgitation. Symptoms of aortic stenosis and regurgitation typically include shortness of breath and chest pain on exertion. The increased cardiac workload can lead to heart failure.
2.2 Surgical aortic valve replacement with an artificial prosthesis (biological or mechanical) is the conventional treatment for patients with severe aortic valve dysfunction who are well enough for open heart surgery. Although bioprosthetic valves have some advantages over mechanical valves, they may degenerate and fail over time. The standard treatment for a failed bioprosthetic valve is repeat open heart surgery, with a further valve replacement. Re‑operative surgery is associated with significant morbidity and a higher risk of mortality than primary surgery. Valve-in-valve transcatheter aortic valve implantation (ViV‑TAVI) has been developed as a less invasive alternative treatment that avoids the need for cardiopulmonary bypass. It can be used for the treatment of failed bioprosthetic aortic valves originally placed either by TAVI or by open heart surgery. In particular, it has been used for rescue of suboptimal TAVI.