An examination of the relationship between serum uric acid level, a clinical history of gout, and cardiovascular outcomes among patients with acute coronary syndrome.

BACKGROUND: Studies have suggested a relationship between higher baseline serum uric acid (sUA) levels and an elevated risk of subsequent ischemic cardiovascular outcomes among acute coronary syndrome (ACS) patients; this relationship may be modified by a clinical history of gout and has not been studied in large patient cohorts. We sought to understand the effect of sUA and gout on ACS outcomes.
METHODS: Using PLATO and TRACER data on 27,959 ACS patients, we evaluated baseline sUA levels in relation to a composite of cardiovascular death, myocardial infarction (MI), or stroke. We assessed interaction terms to determine if a baseline clinical diagnosis of gout modified this putative relationship; 46% (n=12,882) had sUA levels elevated >6.0 mg/dL.
RESULTS: Patients with elevated levels were more often male with a history of prior MI, diabetes, and heart failure compared with those with sUA <6.0 mg/dL. The unadjusted risk of the composite endpoint increased with corresponding elevations in sUA levels (per 1 mg/dL increase) (HR=1.23 [95% CI: 1.20-1.26]) above the statistical inflection point of 5.0 mg/dL. After adjustment, the association between sUA level and the composite outcome remained significant (HR=1.07 [95% CI: 1.04-1.10]), and baseline gout did not modify this relationship.
CONCLUSIONS: In patients with ACS, increasing levels of sUA are associated with an elevated risk of cardiovascular events, regardless of a clinical diagnosis of gout. Further investigation is warranted to determine the mechanism behind this relationship and to delineate whether sUA is an appropriate therapeutic target to reduce cardiovascular risk.