Although the role of XO in CHF is not clearly established, it appears that its inhibition (independent of urate-lowering) in patients with hyperuricaemia may have a beneficial effect on endothelial cell function, myocardial function and ejection fraction, while in contrast, reducing urate levels with probenecid or benzbromarone does not improve endothelial cell function or haemodynamic impairment, despite a significant decrease in serum urate level [for references see [47-50]. Here, XDH is linked to congestive heart failure.