Xanthine oxidase inhibition and cardiovascular protection: Don't shoot in the dark

Substantial evidence suggests that chronic hyperuricemia is an independent risk factor for hypertension, metabolic syndrome, chronic kidney disease and cardiovascular disease. However, whether lowering serum UA can improve cardiovascular and renal outcomes, and what therapeutic mechanism of action could provide more clinical benefits to patients, is still a matter of discussion. Evidence from observational studies suggests possible cardiovascular benefits associated with ULT, in particular for the XO-inhibitors, while the evidence from randomized controlled trials is scarce and somewhat conflicting. These discrepancies could be explained by the existence of different phenotypes across hyperuricemic patients with a non-homogeneous distribution of clinical benefits from ULT.