Uric Acid Is Associated with Worsening of Diastolic Function and Adverse Outcomes in Patients with Coronary Slow Flow

Objective: The impact of uric acid on worsening of diastolic function and clinical outcomes in patients with coronary slow flow remains unclear. This study aims to investigate possible associations between serum uric acid, worsening of diastolic function, and major adverse cardiovascular events in coronary slow flow patients. Methods: Blood samples were obtained prospectively from 537 patients who had been angio-graphically diagnosed with coronary slow flow. Of those, 425 patients underwent comprehensive cardiac function assessment both before and after maximal treadmill exertion by stress echocardiography. The association between serum uric acid and major adverse cardiovascular events was examined using Cox proportional hazards regression model. Results: Among the 425 patients (mean age: 58 +/- 11 years; 52.2% men), worsening of diastolic function occurred in 176 (41.4%) after exercise stress. Patients with worsening of diastolic function had elevated levels of serum uric acid compared to those without (5.7 [4.1, 6.7] vs 4.3 [3.6, 5.3] mg/dL, respectively; P < .001). Higher serum uric acid levels were also significantly associated with neutrophil counts and high-sensitive C-reactive protein in patients with worsening of diastolic function but not in those without. Multivariate regression analysis found serum uric acid to be an independent predictor of worsening of diastolic function (odds ratio = 1.87 [1.17-3.82], P = .023). Moreover, serum uric acid remained associated with major adverse cardiovascular events even after adjusting for echocardiographic and clinical variables (hazard ratio = 1.56 [1.03-2.89], P = .016). Conclusion: Serum uric acid is associated with worsening of diastolic function and may be mediated by inflammation. These findings indicate that uric acid is a risk factor for major adverse cardiovascular events in patients with coronary slow flow.