The Influence of Serum Uric Acid on Risks of Major Adverse Cardiovascular Events in Patients with Acute Coronary Syndrome

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. All patients received standard ACS care, and SUA levels were retrospectively analyzed. The primary outcome was major adverse cardiovascular events (MACE), defined as all-cause mortality (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 rates of MACE (19.54%), re-MI (2.9%), 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 (11.94%) between groups (11.48% vs. 12.93%, p  = 0.5508). Kaplan–Meier analysis at 60 months showed 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 demonstrated an association between SUA ≥ 7.25 mg/dL and increased MACE (odds ratio = 1.639, 95% confidence interval [CI] = 1.084–2.477, p  = 0.0191). Cox regression revealed higher risks 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, drug-eluting stent, and number of diseased vessels. Conclusions: Elevated SUA is associated with increased risks of MACE, re-MI, and ACM in patients with ACS. Routine SUA assessment may help identify high-risk individuals for closer monitoring and tailored management. Clinical trial number: Not applicable.