High Uric Acid Levels in Acute Myocardial Infarction Provide Better Long-Term Prognosis Predictive Power When Combined with Traditional Risk Factors

Abstract

The current study aimed to investigate the association between serum UA levels and the mortality rate of AMI patients. We analyzed 5888 patients with successfully revascularized AMI (mean age: 64.0 ± 12.7 years). The subjects were divided into the high UA group (uric acid >6.5 mg/dL for males, >5.8 mg/dL for females) or the normal UA group based on initial serum UA level measured at admission. The primary outcome was all-cause mortality. A total of 4141 (70.3%) and 1747 (29.7%) patients were classified into the normal UA group and high UA groups, respectively. Over a median follow-up of 5.02 (3.07, 7.55) years, 929 (21.5%) and 532 (34.1%) patients died in each group. Cox regression analysis identified high UA levels as an independent predictor of all-cause mortality (unadjusted hazard ratio (HR) 1.69 [95% CI 1.52–1.88]; p < 0.001, adjusted HR 1.18 [95% CI: 1.05–1.32]; p = 0.005). The results were consistent after propensity-score matching and inverse probability weighting to adjust for baseline differences. The predictive accuracies of conventional clinical factor discrimination and reclassification were significantly improved upon the addition of hyperuricemia (C-index 0.788 [95% CI 0.775–0.801]; p = 0.005, IDI 0.004 [95% CI 0.002–0.006]; p < 0.001, NRI 0.263 [95% CI 0.208–0.318]; p < 0.001).