The major cardiovascular events of febuxostat versus allopurinol in treating gout or asymptomatic hyperuricemia: a systematic review and meta-analysis

Background: To evaluate the major cardiovascular (CV) events of febuxostat compared to allopurinol for the treatment of gout or asymptomatic hyperuricemia. Methods: Relevant studies published until August 15, 2020 were identified by a systematic search of the PubMed and Wiley Online Library databases. Any controlled clinical trial, randomised controlled trial (RCT), retrospective cohort study or open label trial (OLT) comparing febuxostat in patients with gout or hyperuricemia with allopurinol. The quality of all identified studies was assessed based on Cochrane Collaboration's risk of bias tool. Odds ratios (OR) were calculated with random effects and reported with corresponding 95% confidence intervals (CI). Results: Eighteen studies were ultimately included in the analysis, among them 6 articles mentioned serum uric acid (sUA) level before and after treatment, 14 articles mentioned major cardiovascular events, 5 articles mentioned cardiovascular death, 6 articles mentioned skin reactions, 6 articles mentioned musculoskeletal and connective tissue signs and symptoms, 4 articles mentioned joint-related signs and symptoms, 6 articles mentioned upper respiratory infection, 5 articles mentioned gastrointestinal reaction and 7 articles mentioned all-cause mortality. The febuxostat group showed significantly lower sUA levels than allopurinol group (MD =-0.83, 95% CI: -1.22 to -0.44, P<0.0001, I-2=98%). There was no markedly difference between the febuxostat and allopurinol (OR 1.01, 95% CI: 0.83 to 1.23, P=0.84, I-2=95%) in the major cardiovascular events. The occurrence of skin reactions of febuxostat was significantly fewer than allopurinol (OR 0.55, 95% CI: 0.42 to 0.73, P<0.0001, I-2=49%). Regarding to occurrence of CV death, musculoskeletal and connective tissue signs and symptoms, febuxostat group was higher than allopurinol group. However, among patients with gout or hyperuricemia, treatment with febuxostat resulted in other adverse reactions, including all-causes mortality similar to those associated with allopurinol. Discussion: The limitation of the study was the included studies show high heterogeneity in regard to their design. There was no difference in the incidence of major cardiovascular events between febuxostat and allopurinol, and febuxostat was better in lowering uric acid and has less adverse skin reactions than allopurinol, but the risk of CV death of febuxostat was higher than allopurinol.