Abstract Sa502: Early uric acid clearance and survival after out-of-hospital cardiac arrest: A prospective observational study

Background: Hyperuricemia is frequently seen in patients after cardiac arrest. Persistent hyperuricemia during a cellular energy crisis is believed to result from the breakdown of nucleotides into uric acid (UA) and indicates an insufficient restoration of adenosine triphosphate (ATP) synthesis. Hypothesis: Early reduction in serum UA level, UA clearance (UA-CL), is associated with survival after cardiac arrest. Aims: The study examined the association between UA-CL and 30-day survival following out-of-hospital cardiac arrest (OHCA). Methods: This was a prospective, multicenter, observational study of OHCA cases conducted from 2019 to 2021. The study included adult non-traumatic OHCA patients whose UA levels were measured upon hospital arrival (UA-0h) and 24 hours after cardiac arrest (UA-24h). The proportional change from UA-0h to UA-24h was represented as UA-CL (%). The primary outcome was 30-day survival. An association between UA-CL and 30-day survival was investigated using restricted cubic spline regression and multivariable logistic regression analysis fitted with generalized estimating equations adjusted for patient characteristics, pre-hospital information, resuscitation variables, and within-institution clustering. Results: Among a total of 9,909 OHCA patients, 375 patients were included in the analysis. Compared to the non-survivors (N=166), the survivors (N=209) had more cases of witnessed arrests, bystander CPR, initial shockable rhythms, cardiogenic arrests, and a shorter duration of cardiac arrest. However, there was no difference in UA-0h between survivors and non-survivors (median 7.5 [IQR: 6-9] mg/dL, 7.4 [6-9] mg/dL, respectively; P=0.72). In contrast, UA-CL was significantly higher among the survivors compared to non-survivors (21 [3-42]%, 2.5 [-16-26]%, respectively; P<0.001). Cubic spline curb showed a linear increase in odds for survival with positive UA-CL. Finally, UA-CL was independently associated with 30-day survival after accounting for covariates (adjusted OR 1.01 [1.00-1.02], P=0.04). Conclusion: Regardless of UA-0h level, UA-CL was independently associated with 30-day survival after OHCA. Early UA-CL after cardiac arrest warrants research as an exploitable target to improve outcomes.