title: Xanthine oxidase inhibition for the treatment of cardiovascular disease: an updated systematic review and meta-analysis.
abstract: BACKGROUND
  Previous studies have shown that xanthine oxidase inhibitors (XOI) might improve outcome for patients with cardiovascular disease. However, more evidence is required.
  
  
  RESULTS
  We published a meta-analysis of trials conducted before 2014 examining the effects of XOI on mortality in patients with cardiovascular disease. At least two further trials (N= 323 patients) have since been published. Accordingly, we repeated our analysis after a further search for randomized controlled trials of XOI in PubMed/MEDLINE, EMBASE, and Cochrane Databases. We identified eight relevant trials with 1031 patients. The average age of the patients was 61 years and 68% were men (one study did not report gender). There were 57 deaths in these eight trials, 26 in those assigned to XOI, and 31 in those assigned to the control. The updated meta-analysis could not confirm a reduction in mortality for patients assigned to XOI compared with placebo (odds ratio 0.84) but 95% confidence intervals were wide (0.48-1.47).
  
  
  CONCLUSIONS
  This updated meta-analysis does not suggest that XOI exert a large reduction in mortality but also cannot exclude the possibility of substantial harm or benefit.
authors.affiliation: Academic Cardiology, Castle Hill Hospital, Hull York Medical School, University of Hull Kingston upon Hull UK.
authors.forename: Jufen
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Cardiovascular Center, OLV Hospital Aalst Belgium.
authors.forename: Riet
authors.initials: R
authors.lastname: Dierckx
authors.affiliation: Academic Cardiology, Castle Hill Hospital, Hull York Medical School, University of Hull Kingston upon Hull UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: Mohee
authors.affiliation: Academic Cardiology, Castle Hill Hospital, Hull York Medical School, University of Hull Kingston upon Hull UK.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Clark
authors.affiliation: The National Heart and Lung Institute, Royal Brompton and Harefield Hospitals, Imperial College London UK.
authors.forename: John G
authors.initials: JG
authors.lastname: Cleland
keywords: Cardiovascular disease; Meta‐analysis; Mortality; Systematic review; Xanthine oxidase inhibition