A Study of Prognostic Importance of Serum Uric Acid Level in Patients with Acute Myocardial Infarction

Introduction: Acute myocardial infarction (AMI) remains a major cause of morbidity and mortality worldwide despite advances in diagnostic and therapeutic strategies. Early identification of patients at increased risk of adverse outcomes is essential for effective risk stratification and optimal management. Serum uric acid, the final product of purine metabolism, has been implicated in oxidative stress, endothelial dysfunction, and inflammation, all of which contribute to cardiovascular injury. Several studies have suggested an association between elevated serum uric acid levels and poor clinical outcomes following AMI. However, its prognostic utility remains controversial across different populations. Therefore, the present study was undertaken to evaluate the prognostic significance of serum uric acid levels in patients presenting with acute ST-segment elevation myocardial infarction. Materials and Methods: This prospective observational cohort study was conducted in the Department of General Medicine at Ozone Hospitals, Hyderabad, India, between June 2023 and January 2024. A total of 100 consecutive patients diagnosed with acute ST-segment elevation myocardial infarction (STEMI) were enrolled. Demographic characteristics, cardiovascular risk factors, clinical findings, laboratory investigations, electrocardiographic parameters, and echocardiographic findings were recorded at admission. Serum uric acid levels were measured using the enzymatic uricase method. Hyperuricemia was defined as serum uric acid >7.0 mg/dL in men and >5.6 mg/dL in women. Patients with conditions or medications known to influence serum uric acid levels were excluded. All patients were monitored throughout hospitalization for clinical outcomes including mortality, heart failure, and arrhythmias. Clinical characteristics were compared between normal uric acid and hyperuricemia groups. Multivariate logistic regression analysis was performed to identify independent predictors of mortality after adjustment for potential confounding variables. Statistical significance was considered at p<0.05. Results: The study included 100 patients with STEMI, with a mean age of 55.0 ± 9.7 years; 75% were male. Hypertension, smoking, dyslipidemia, and diabetes mellitus were present in 38%, 45%, 32%, and 30% of patients, respectively. Anterior wall myocardial infarction (45%) was the most common presentation, followed by inferior wall myocardial infarction (41%). The mean serum uric acid level was 5.85 ± 1.85 mg/dL. Patients with hyperuricemia were significantly older and had higher serum creatinine levels than those with normal uric acid levels. Short-term mortality was significantly greater in the hyperuricemia group (19.4% vs. 6.4%, p=0.020). Non-survivors had significantly higher serum uric acid levels than survivors (6.71 ± 1.38 mg/dL vs. 4.45 ± 1.29 mg/dL, p<0.001). Multivariate logistic regression identified serum uric acid as an independent predictor of mortality (adjusted OR 6.76; 95% CI: 1.018–178.540; p=0.015). Conclusion: Elevated admission serum uric acid levels are significantly associated with adverse outcomes in patients with acute ST-segment elevation myocardial infarction. Serum uric acid serves as an independent predictor of mortality and may be a useful, inexpensive biomarker for early risk stratification in acute myocardial infarction