Superiority of the SUA/eGFR Ratio in predicting early hard events in STEMI: A large-scale head-to-head comparison and J-shaped risk discovery
J Y Ren, Z Zhang, H Zhang, X Shao, R X Guo, Z K Xue, X Liu, T Liu, K ChenAbstract
Background
Early risk stratification is paramount for ST-segment elevation myocardial infarction (STEMI). While various uric acid-based indices exist, their comparative prognostic value remains unclear.
Purpose
We aimed to identify the optimal index and explore potential non-linear relationships.
Methods
We analyzed 39,941 STEMI patients from a large-scale real-world database. The primary endpoint was three-month hard cardiac events (cardiac death and re-infarction). The secondary endpoint was a composite of cardiac death, re-infarction, and non-fatal stroke (3-point major adverse cardiovascular events [MACE]). Phase one involved a head-to-head comparison of five indices: serum uric acid (SUA), SUA/estimated glomerular filtration rate (eGFR), SUA/albumin (UAR), SUA/high-density lipoprotein (HDL) (UHR), and SUA/creatinine. Phase two assessed the incremental predictive value via net reclassification index (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). Restricted cubic splines (RCS) were employed to examine nonlinear associations.
Results
Among all tested indices, SUA/eGFR demonstrated the highest discriminatory power for three-month hard endpoints (area under the curve [AUC]: 0.658 vs. 0.550–0.620 for others, Figure 1B) and three-month three-point MACE (AUC: 0.644 vs. 0.550–0.610 for others, Figure 1C). Notably, restricted cubic spline analysis unveiled a significant J-shaped association between SUA/eGFR and hard endpoints (P for non-linearity < 0.05), indicating that both excessively low and high ratios confer elevated risk—a finding that reframes the traditional linear risk paradigm (Figure 1A). Adding SUA/eGFR to the clinical baseline model significantly improved discrimination (AUC increased from 0.747 to 0.752, P < 0.001, Figure 2A) and yielded meaningful risk reclassification (NRI: 0.98%, 95% CI 0.38%–1.56%, P < 0.05; IDI: 0.57%, P < 0.05). Decision Curve Analysis further confirmed that the SUA/eGFR-enhanced model provided a higher net benefit across clinically relevant threshold probabilities (Figure 2B).
Conclusion
The SUA/eGFR ratio is the superior uric acid-based index for predicting early hard cardiac events in STEMI patients. Its distinctive J-shaped relationship with outcomes—challenges conventional linear risk assessment and identifies a vulnerable window at both extremes. Integrating this simple, readily available ratio into established clinical models significantly enhances prognostic accuracy and supports personalized risk management at the bedside.J-shaped risk and index AUC comparisonIncremental model value and DCA curves