INVITED COMMENTARY

Abstract

A great deal has been published recently that has associated homograft dysfunction and failure with various immunological factors. Many of these factors are not modifiable. It is clear that homografts deteriorate over time and require regular follow-up. The authors of the current study have attempted to address the practical and important question of predicting homograft dysfunction. Their echocardiographic follow-up in a series of 64 Ross patients demonstrates a progressive decrease in annular size and an increase in gradient, with one third of patients having a mean gradient of > 20 mm Hg develop. Similar to several other studies most of the progression of dysfunction is in the first couple of years. They have confirmed a number of the variables that have usually been associated with homograft dysfunction and failure, although they did not find other know factors (ABO mismatch, age) to be associated with failure. This is not surprising because like most homograft studies this is a small series from a single centre.Nonetheless the novel finding in this study is that a mild gradient at 1 year (> 9 mm Hg) was associated with the subsequent development of stenosis. This is a useful observation in terms of patient management and the planning of further follow-up. It is important to note that the incidence of homograft dysfunction in this series is much higher than that seen in other series of Ross patients and likely relates (as the authors note) to the methods of procurement and preservation. In addition, several important factors (human leukocyte antigen mismatch and blood product use) were not available. However the finding that an early gradient is associated with progression to significant stenosis is probably true and certainly bares further study.This article also highlights the important fact that the Ross procedure yields a patient with double valve disease, and although it is clearly the best option in young children, these patients need careful follow-up. Further understanding of homograft dysfunction, and importantly interventions to limit or prevent it, will require multicenter cooperation. At the very least, the standardization of procurement and preservation techniques, as well as follow-up and echocardiographic reporting, is essential to further study and optimize the use and function of homograft valves. A great deal has been published recently that has associated homograft dysfunction and failure with various immunological factors. Many of these factors are not modifiable. It is clear that homografts deteriorate over time and require regular follow-up. The authors of the current study have attempted to address the practical and important question of predicting homograft dysfunction. Their echocardiographic follow-up in a series of 64 Ross patients demonstrates a progressive decrease in annular size and an increase in gradient, with one third of patients having a mean gradient of > 20 mm Hg develop. Similar to several other studies most of the progression of dysfunction is in the first couple of years. They have confirmed a number of the variables that have usually been associated with homograft dysfunction and failure, although they did not find other know factors (ABO mismatch, age) to be associated with failure. This is not surprising because like most homograft studies this is a small series from a single centre. Nonetheless the novel finding in this study is that a mild gradient at 1 year (> 9 mm Hg) was associated with the subsequent development of stenosis. This is a useful observation in terms of patient management and the planning of further follow-up. It is important to note that the incidence of homograft dysfunction in this series is much higher than that seen in other series of Ross patients and likely relates (as the authors note) to the methods of procurement and preservation. In addition, several important factors (human leukocyte antigen mismatch and blood product use) were not available. However the finding that an early gradient is associated with progression to significant stenosis is probably true and certainly bares further study. This article also highlights the important fact that the Ross procedure yields a patient with double valve disease, and although it is clearly the best option in young children, these patients need careful follow-up. Further understanding of homograft dysfunction, and importantly interventions to limit or prevent it, will require multicenter cooperation. At the very least, the standardization of procurement and preservation techniques, as well as follow-up and echocardiographic reporting, is essential to further study and optimize the use and function of homograft valves.