Cardiovascular events in hyperuricemia population and a cardiovascular benefit-risk assessment of urate-lowering therapies: a systematic review and meta-analysis

BACKGROUND: Hyperuricemia and gout have become public health concerns; many important guidelines have recommended xanthine oxidase inhibitors (XOIs) as the first-line urate-lowering therapies (ULTs) to treat chronic gout with hyperuricemia. However, whether treating hyperuricemia and gout with ULTs modifies cardiovascular risks remains controversial. The aim of this study was to assess the incident risk of cardiovascular (CV) events (CVE) in hyperuricemia population, assess the cardiovascular benefit-risk of ULTs in hyperuricemia patients with or without gout in diverse cardiovascular risk sub-groups, and specify the safety of different ULTs. METHODS: We searched PubMed, Embase, the Cochrane Library, Wanfang, Chongqing VIP (CQVIP, en.cqvip.com), and China National Knowledge Infrastructure Database for prospective cohort studies and randomized controlled trials (RCTs) in English and Chinese. Potential medications included XOIs, and uricosurics. RCTs were divided into sub-groups analysis based on blinding status and patients’ history of CV diseases. Risk ratios (RRs) were calculated and were reported with corresponding 95% confidence intervals (CIs) by fixed-effects or random-effects model. RESULTS: Seven prospective cohort studies and 17 RCT studies were included. The risks of both major adverse cardiovascular events (MACE) (RR = 1.72, 95% CI 1.28–2.33) and CVE (RR = 1.35, 95% CI 1.12–1.62) were higher in the hyperuricemia population than non-hyperuricemia one. In seven RCT studies where XOIs were compared with no-treatment or placebo, the results of five low CV risk studies showed that XOIs lowered the risks of both MACE (RR = 0.35, 95% CI 0.20–0.62) and CVE (RR = 0.61, 95% CI 0.44–0.85); whereas two high CV risk studies showed that XOIs lowered the risk of CVE (RR = 0.69, 95% CI 0.54–0.88) rather than MACE (RR = 0.62, 95% CI 0.29–1.35). In nine RCT studies where the cardiovascular safety between febuxostat and allopurinol were compared, no statistical difference was found in the risk of MACE or CVE. CONCLUSIONS: The hyperuricemia population does have a higher incidence of CVE, and the results suggested that XOIs might reduce the incidence of MACE and total CVE. In addition, from the perspective of cardiovascular safety, febuxostat equaled allopurinol in our meta-analysis.