Association of the Uric Acid-to-Magnesium Ratio and Frontal QRS-T Angle with Angiographic Coronary Disease Severity in Acute Coronary Syndrome.

Background: The uric acid-to-magnesium (UA/Mg) ratio and frontal QRS-T angle have been associated with coronary artery disease, but their relationships with angiographic coronary disease severity in acute coronary syndrome (ACS) remain incompletely characterized. We investigated their associations with the Gensini score in patients with ACS. Methods: This single-center, retrospective observational study included 146 patients with ACS undergoing coronary angiography, including 85 with ST-segment elevation myocardial infarction (STEMI) and 61 with non-ST-segment elevation myocardial infarction (NSTEMI). The primary adjusted analysis evaluated the continuous Gensini score after natural logarithmic transformation using multivariable linear regression with HC3 robust standard errors. Median quantile regression was performed as a sensitivity analysis. A Gensini score ≥ 60 was evaluated as a secondary exploratory binary endpoint using a parsimonious multivariable logistic regression model, with bootstrap internal validation. Results: The UA/Mg ratio (ρ = 0.332; p < 0.001), uric acid-to-HDL cholesterol ratio (UHR) (ρ = 0.232; p = 0.005), and frontal QRS-T angle (ρ = 0.481; p < 0.001) correlated positively with the Gensini score. In the primary adjusted analysis, both the UA/Mg ratio (β = 0.294 per 1-SD increase; p < 0.001) and frontal QRS-T angle (β = 0.225 per 1-SD increase; p < 0.001) were independently associated with higher log-transformed Gensini scores. These associations remained significant in median quantile regression and after additional adjustment for C-reactive protein. Modeling uric acid and magnesium separately provided better model fit than use of the UA/Mg ratio. In the secondary exploratory analysis of a Gensini score ≥ 60, the UA/Mg ratio (OR = 1.86 per 1-SD increase; 95% CI: 1.22-2.95; p = 0.005) and frontal QRS-T angle (OR = 1.54 per 1-SD increase; 95% CI: 1.05-2.30; p = 0.030) remained independently associated with the endpoint. The parsimonious model had an apparent AUC of 0.787 and an optimism-corrected AUC of 0.765 after bootstrap internal validation. Conclusions: Higher UA/Mg ratio and wider frontal QRS-T angle were independently associated with a higher log-transformed Gensini score in the primary continuous-outcome analysis in patients with ACS. However, the UA/Mg ratio did not demonstrate statistical superiority over its individual components, and the secondary binary model showed only moderate discrimination after internal validation. These findings should be considered exploratory and require prospective external validation.