Limitation
Beside the known limitations inherent to the retrospective nature of this study we acknowledge some other limitations. For this study, we used the WHO definition for MetS, and perhaps the use of different definitions such as the NCEP/ATP 3 or IDF could have potentially led to different results. For the obesity, the latter two definitions refer more specifically to waist circumferences rather than BMI>30 kg\m2, pointing the focus to the visceral adiposity(16). Microalbuminuria, an adjunctive criterion for the WHO definition of MetS, was not recoded in our dataset.
Long term follow-up was not carried out; hence we could not evaluate the impact of MetS at distance. In fact, an important aspect of MetS is the tendency to accelerated development of pressure gradient in the bioprosthetic valve(22). Nevertheless, the progression of aortic bioprosthetic valve gradient and stenosis was not investigated.