Serum uric acid to eGFR ratio correlates with adverse outcomes in elderly hospitalized for acute heart failure

Background: Serum uric acid (SUA) is a known biomarker of severity in acute heart failure (AHF), reflecting the intricate interplay between cardiovascular and metabolic dysfunction. Since SUA can increase in response to worsening kidney function, and subjects with AHF often have cardiorenal syndrome or are on diuretic therapy, we tested whether the ratio of SUA to eGFR might provide prognostic value in elderly hospitalized for AHF. Methods: The BOTERO-AHF Study (BOlogna study of Therapies, Epidemiology and Radiodiagnostic Outcomes in Acute Heart Failure patients) included 293 patients admitted for AHF who were consecutively enrolled from January 2020 onwards. We compared the baseline characteristics of participants who had a composite outcome (CO) (n = 203) of death or re-hospitalization for AHF within 12 months from discharge to those without CO (n = 90), and we assessed the prognostic impact of SUA/eGFR for 12-months CO. Results: SUA/eGFR was significantly higher in participants who experienced a CO within 12 months from discharge for AHF, compared to those who did not experience any CO (17.8 (16.6) vs. 13.7 (12.1) mg/dl/ml/min*100, p = 0.008). SUA/eGFR, and not SUA alone, was associated with an increase in the rate of CO (unadjusted HR 1.011, CI 95% 1.004-1.019, p = 0.003). This association lost significance in participants under treatment with xanthine oxidase inhibitors but remained significant after adjustment for multiple confounders. Conclusion: The SUA/ eGFR ratio provides prognostic value in elderly patients hospitalized for AHF. Future studies may clarify if SUA/eGFR and XOI may represent novel diagnostic and therapeutic approaches for subgroups of patients with AHF.