Serum Urate as an Independent Predictor of Poor Outcome and Future Vascular Events After Acute Stroke

Abstract

Background and Purpose— Serum urate concentration is associated with cardiovascular disease, and hyperuricemia predicts first-ever stroke. We explored the association of admission urate level with mortality, placement, and risk of further vascular events after acute stroke. Methods— In patients with ischemic stroke or primary intracranial hemorrhage, we determined the association of urate level with 90-day placement (alive at home, good outcome; dead or living in care, poor outcome) and with the subsequent occurrence of ischemic stroke, myocardial infarction, or vascular death. In multivariate analysis (logistic regression for 90-day placement, proportional-hazards regression for time to further vascular event), we adjusted for stroke severity (modified National Institutes of Health stroke scale) and other clinical, biochemical, and radiological variables known to influence stroke outcome. Results— We studied 3731 patients and measured serum urate in 2498. Elevated urate level predicted a lower chance of good 90-day outcome (odds ratio, 0.78 per additional 0.1 mmol/L; 95% confidence interval [CI], 0.67 to 0.91) independently of stroke severity and other prognostic factors. Vascular event risk increased with urate level (relative hazard, 1.27 per additional 0.1 mmol/L; 95% CI, 1.18 to 1.36). Higher urate levels have a greater effect on vascular event rates in the presence of diabetes (additional relative hazard, 1.22 per additional 0.1 mmol/L; 95% CI, 1.06 to 1.41). Conclusions— Independently of other prognostic factors, higher serum urate levels predicted poor outcome (dead or in care) and higher vascular event rates. The role of urate in stroke pathophysiology remains uncertain, but intervention to lower urate may be worth considering.