Relationship of serum uric acid and Killip class on mortality after acute ST-segment elevation myocardial infarction and primary percutaneous coronary intervention.

Background: There is conflicting information regarding the association between hyperuricemia and survival in STEMI patients. Our study examined the interaction between hyperuricemia and Killip class on mortality of STEMI patients.

Methods: We analyzed 951 consecutive STEMI patients between February 2006 and September 2012. Hyperuricemia was defined as SUA of at least 7mg/dL in males and 6mg/dL in females. Killip class I patients were divided into hyperuricemia and normouricemia groups.

Results: The Killip class I hyperuricemia and normouricemia groups had similar baseline and procedural characteristics, but the hyperuricemia group had significantly greater BMI, serum creatinine, and SUA, and a lower TIMI risk score (2, IQR: 1-4 vs. 3, IQR: 2-4, p=0.019). The hyperuricemia group also had greater 30-day and 1-year mortality rates (2.9% vs. 0.3%, p=0.022; 6.5% vs. 1.1%, p=0.002, respectively). However, hyperuricemia was not associated with mortality of patients in Killip classes II-IV or in the overall study population. Hyperuricemia was associated with increased mortality in subgroups of patients who were at least 65years-old, male, had BMI of 25kg/m or less, were in Killip class I, without diabetes, and who did not receive intra-aortic balloon pump support. Hyperuricemia interacted with Killip class I in increasing the risk for 1-year mortality (p for interaction=0.038).

Conclusions: Hyperuricemia increased the 1-year mortality of STEMI patients in Killip class I, but not of patients in Killip classes II-IV. An interaction of hyperuricemia and Killip class significantly affects the mortality of STEMI patients.