Comparing Cardiovascular Safety of Febuxostat and Allopurinol in the Real World: A Population-Based Cohort Study.

To determine and compare the risk of cardiovascular events and mortality of febuxostat and allopurinol use.We conducted a cohort study using the Taiwan National Health Insurance Research Database. New users of febuxostat and allopurinol between April 1, 2012 and December 31, 2015 were identified, and the two groups were 1:1 matched by propensity score, benzbromarone use history, renal impairment, and time of drug initiation. The risk of major adverse cardiovascular events (MACEs), venous thromboembolism (VTE), heart failure (HF) hospitalization, atrial fibrillation hospitalization, cardiovascular (CV) death, and all-cause mortality was assessed using Cox proportional hazards models. The dose-response relationship between xanthine oxidase inhibitor use and adverse CV outcomes were also determined.A total of 44,111 patients were included for each group, and all baseline covariates were well matched. Febuxostat users were at a significantly higher risk for HF hospitalization (hazard ratio [HR], 1.22; 95% CI, 1.13-1.33), atrial fibrillation hospitalization (HR, 1.19; 95% CI, 1.05-1.36), and CV death (HR, 1.19; 95% CI, 1.03-1.36) than allopurinol users, whereas no difference was found for the major adverse cardiac events composite endpoint, venous thromboembolism, myocardial infarction, ischemic stroke, and all-cause mortality. The elevated risk of HF hospitalization was consistent throughout the primary and sensitivity analyses. In addition, febuxostat increased the risk of adverse CV outcomes in a dose-dependent manner.The use of febuxostat, compared with allopurinol, was associated with a significantly increased risk of adverse CV events. Higher febuxostat doses had a greater impact. Further studies are needed to investigate the mechanisms linking febuxostat to adverse CV outcomes.