Evaluation of the Relationship Between Serum Uric Acid Levels and Cardiovascular Events in Patients With Gout: A Retrospective Analysis Using Electronic Medical Record Data.

OBJECTIVES: The aim of this study was to evaluate relationships between serum uric acid (SUA) and newly emergent acute myocardial infarction (AMI), congestive heart failure (CHF), coronary artery disease (CAD), composite cardiovascular (CV) events (AMI, CHF, CAD), hypertension, hyperlipidemia, and renal disease in gout patients.

METHODS: Retrospective analysis of electronic medical records from Humedica identified adults (≥18 years) with 2 or more International Classification of Diseases, Ninth Revision, Clinical Modification codes for gout 30 days or more apart (first diagnosis = index event) having 1 or more SUA assessment on or after the index date, and at least 6 months preindex and at least 12 months postindex enrollment. Outcomes were measured during 12 months postindex; patients with preindex events were excluded from analysis of those events. The SUA level (0.01-4.00 mg/dL, 4.01-6.00 mg/dL, 6.01-8.00 mg/dL, and ≥8.01 mg/dL) was determined using the closest laboratory assessment before or on the date of the CV event. Tukey-Kramer comparisons were performed for pairs of SUA strata and Cox proportional model estimated hazard ratios.

RESULTS: A significantly higher incidence of AMI, CHF, and renal disease was observed for patients with 8.01 mg/dL or greater relative to other SUA levels (P < 0.0001), and a significantly higher incidence of composite CV events (AMI, CHF, and CAD) was observed for hypouricemia (SUA, 0.01-4.00 mg/dL) compared with other SUA levels (P < 0.0001). Cox models confirmed the increased risk associated with SUA 8.01 mg/dL or greater; hazard ratios ranged from 1.16 for hypertension to 2.04 for renal disease. Hyperlipidemia and hypertension were diagnosed concurrently with gout in 24% and 28% of patients, respectively.

CONCLUSIONS: Hyperuricemia and hypouricemia were associated with an increased risk of CV events.