Clinical outcomes in patients with cardiorenal multimorbidity: the role of serum uric acid/serum creatinine ratio

Introduction Serum uric acid (SUA), the final product of purine metabolism, is an independent risk factor for cardiovascular (CV) disease. Since SUA levels depend on renal function, SUA to serum creatinine ratio (SUA/sCr) is emerging as a more specific biomarker of CV risk. Aim To evaluate in hospitalized patients with cardiorenal multimorbidity (CRM) if the SUA/sCr≥5.35 is associated with clinical outcomes. The primary outcome was in-hospital mortality. The secondary outcome was the composite of all-cause of mortality and adverse clinical events. Methods We conducted a retrospective review of medical records from consecutive CRM inpatients admitted to the medi- cal ward. The composite endpoint was calculated as all-cause mortality and adverse clinical events such as acute coronary syndrome, stroke, infections, and renal replacement therapy. Results In our cohort, 141 patients (mean age of 75.6±10.2 years) were identified with CRM. In-hospital mortality occurred in 17 patients (16%), and 64 patients (60.4%) experienced adverse clinical outcomes. Among the 106 patients, 20 (18.9%) had an SUA/sCr≥5.35, while 86 (81.1%) had an SUA/sCr<5.35. Male gender was significantly associated with SUA/ sCr≥5.35 (p=0.007). In-hospital mortality was significantly higher in patients with SUA/sCr≥5.35 (p=0.010), and a posi- tive correlation with adverse clinical outcomes was documented in this subgroup (p=0.012). Conclusion in patients with CRM, SUA/sCr≥5.35 is associated with increased in-hospital mortality and worse clinical outcomes. The ratio and related cut-off value of SUA/sCr could represent a useful biomarker to assess in-hospital complica- tions in CRM patients.