Structural valve degeneration in the transcatheter mitral valve implantation era.

Structural valve degeneration of biological valves continues to be a persistent problem and has assumed greater importance with the advent of transcatheter valve implantation techniques. Considerable variability exists among different studies in reporting the incidence of structural valve degeneration and differentiation with nonstructural valve degeneration and bio-prosthetic valve failures is important. Moreover, the pathological basis of structural valve degeneration is still not completely understood. Theoretically, trans-catheter implanted valves may be more prone to degeneration compared to surgically implanted biological valves. Measures to reduce structural valve degeneration are imperative, irrespective of the technique of valve implantation.