A linear association between serum uric acid and 28-day and 90-day mortality after veno-arterial extracorporeal membrane oxygenation in patients with acute myocardial infarction complicated by cardiogenic shock.

OBJECTIVE: This study aimed to delineate the relationship between serum uric acid (UA) and 28-day and 90-day mortality among patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) receiving veno-arterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: In this retrospective, single-center cohort study, we consecutively enrolled 142 patients supported with VA-ECMO for AMI-CS. Baseline UA was treated as the exposure of interest, and 28-day and 90-day mortality were prespecified primary outcomes. Associations between UA and mortality were evaluated using Cox proportional-hazards models, Kaplan-Meier estimates, receiver operating characteristic curve (ROC), and restricted cubic spline (RCS) regression. RESULTS: Among 142 patients, the median baseline UA level was 452.00 μmol/L (361.00-561.75 μmol/L), and 28-day and 90-day mortality were 33.8% and 40.8%, respectively. After adjustment for potential confounders, each 1 μmol/L increment in UA remained associated with higher hazards of 28-day mortality (HR: 1.002, 95% CI: 1.000-1.003; P = 0.038) and 90-day mortality (HR: 1.002, 95% CI: 1.001-1.004; P = 0.005). Per one standard-deviation increase in UA, the hazards of 28-day and 90-day mortality increased by 37.9% (HR: 1.379, 95% CI: 1.019-1.867; P = 0.038) and 49.4% (HR: 1.494, 95% CI: 1.126-1.982; P = 0.005), respectively. Relative to the low-UA group, the high-UA group exhibited substantially higher risks of both 28-day (HR: 2.499, 95% CI: 1.335-4.677; P = 0.004) and 90-day mortality (HR: 2.262, 95% CI: 1.222-4.188; P = 0.009). ROC analyses indicated a moderate discriminatory performance of UA for 28-day and 90-day mortality, with AUCs of 0.631 (95% CI: 0.532-0.729; P = 0.011) and 0.621 (95% CI: 0.527-0.714; P = 0.015), respectively. Kaplan-Meier curves demonstrated significant separation in cumulative mortality between UA strata, with worse survival in the high-UA group (log-rank P = 0.001). RCS analyses further supported a significant linear association between UA and both endpoints (P for nonlinearity >0.05). CONCLUSIONS: Elevated UA was associated with increased 28-day and 90-day mortality after VA-ECMO in AMI-CS. Given the single-center, retrospective, and observational design, these findings should be interpreted cautiously and require external validation before UA can be considered for clinical risk assessment.