Abstract
BACKGROUND: Acute coronary syndrome (ACS) is a major cause of morbidity and mortality worldwide. Identifying biomarkers that predict outcomes is essential for guiding management. This study evaluated whether elevated serum uric acid (SUA) is associated with increased risks of major adverse cardiovascular events (MACE), recurrent myocardial infarction (re-MI), and all-cause mortality (ACM) in patients with ACS. METHODS: This retrospective cohort study enrolled 829 inpatients with ACS admitted to a tertiary referral hospital in Taiwan from 2015 to 2019. Patients were divided into normal (< 7.25 mg/dL, n = 566) and high (≥ 7.25 mg/dL, n = 263) SUA groups based on a receiver operating characteristic-derived cutoff for whole cohort. All patients received standard ACS care, and SUA levels were retrospectively analyzed. The primary outcome was MACE, defined as ACM, re-MI, and target lesion/vessel revascularization (TLR/TVR), assessed up to 60 months. Kaplan-Meier survival analysis, logistic regression, and Cox proportional hazards regression were applied. RESULTS: The overall incidences of MACE (19.54%), re-MI (2.90%), and ACM (4.46%) were higher in the high SUA group compared with the normal SUA group (MACE: 26.62% vs. 16.25%, p = 0.0005; re-MI: 6.08% vs. 1.41%, p = 0.0002; ACM: 7.22% vs. 3.18%, p = 0.0087). No significant difference was observed in TLR/TVR (overall 11.94%; 11.48% vs. 12.93%, p = 0.5508). Kaplan-Meier analysis at 60 months demonstrated higher event-free rates for MACE, re-MI, and ACM in the normal SUA group (log-rank p = 0.0117, 0.0006, and 0.0261, respectively). Multivariable logistic regression showed that SUA ≥ 7.25 mg/dL was associated with increased odds of MACE (odds ratio = 1.639, 95% confidence interval [CI] = 1.084-2.477, p = 0.0191). Cox regression revealed higher hazards of MACE (hazard ratio [HR] = 1.399, 95% CI = 1.024-1.191, p = 0.0350), re-MI (HR = 3.758, 95% CI = 1.605-8.799, p = 0.0023), and ACM (HR = 1.956, 95% CI = 1.019-3.753, p = 0.0438) in the high SUA group after adjustment for age, uremia, use of drug-eluting stent, and number of diseased vessels. CONCLUSIONS: Elevated SUA is an independent prognostic marker for increased risks of MACE, re-MI, and ACM in patients with ACS. SUA assessment can enhance risk stratification, helping to identify higher-risk patients who may benefit from more intensive secondary prevention strategies and closer follow-up.