Kidney Week

Abstract: FR-PO037

Higher Spot Urinary Sodium Concentration Is Associated with Better Decongestion and Lower Risk of AKI in Acute Heart Failure

Session Information

• AKI: Epidemiology, Risk Factors, and Prevention - 2
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Claure-Del Granado, Rolando, Division of Nephrology, Hospital Obrero No 2 - Caja Nacional de Salud, Cochabamba, Not Applicable, Bolivia, Plurinational State of

Rolando Claure-Del Granado, MD, FASN

• Miranda-Velásquez, Noelia B., Universidad Mayor de San Simon, Cochabamba, Bolivia, Plurinational State of

Noelia B. Miranda-Velásquez, MD

• Villarroel-Espinoza, Sergio, Division of Cardiology, Hospital Obrero No 2 - Caja Nacional de Salud, Cochabamba, Bolivia, Plurinational State of

Sergio Villarroel-Espinoza, MD

• Garcia-Peñaloza, Edward J., Division of Cardiology, Hospital Obrero No 2 - Caja Nacional de Salud, Cochabamba, Bolivia, Plurinational State of

Edward J. Garcia-Peñaloza, MD

• Rivas Salazar, Israel Danny, Division of Nephrology, Hospital Obrero No 2 - Caja Nacional de Salud, Cochabamba, Not Applicable, Bolivia, Plurinational State of

Israel Danny Rivas Salazar, MD

Background

Spot urinary sodium concentration (UNa) is recommended in guidelines for assessing diuretic response and adjusting dosage in acute heart failure (AHF) based solely on expert opinion. This study aims to investigate spot UNa levels in patients admitted with decompensated AHF and evaluate its relationship with acute kidney injury (AKI), its efficacy in guiding decongestion, and its impact on short-term outcomes.

Methods

Fifty consecutive AHF patients were included in the study, all of whom received standard care, including the AKI/STOP protocol for patients with AKI. Spot urinary sodium (UNa) levels were measured six hours after the initiation of diuretic therapy, with diuretic insufficiency defined as a UNa <70 mmol/L. Kidney function was monitored daily for up to 7 days. AKI was defined and classified according to the KDIGO serum creatinine criteria.

Results

The mean age of the patients was 70.84 ± 11.19 years, with 62% being women, and the average left ventricular ejection fraction (LVEF) was 43 ± 14%. Patients who received a lower total furosemide dose within 24 hours (37.86 ± 11.34 mg vs. 43.64 ± 7.90 mg; p=0.014) had a UNa ≤ 70 mmol/L. Twenty-four patients (48%) developed AKI within 48 hours of admission. The risk of AKI was lower in patients with a UNa ≥ 50 mmol/L, with an odds ratio (OR) of 0.02 (95% CI 0.0005-0.130; p < 0.0001). Patients with complete or incomplete recovery from AKI had higher UNa values compared to patients with non-recovery (73.2 ± 29.5 vs. 76.6 ± 22.3 vs. 52.6 ± 26.4; p=0.377). There were no significant differences in terms of signs and/or symptoms of clinical congestion or weight loss (9.7 ± 3.3 kg vs. 10.3 ± 2.4 kg; p=0.445). Patients with a UNa > 70 mmol/L had a lower 30-day mortality rate (2% vs. 10%; p=0.0203) and readmission rate (10% vs. 26%; p=0.0142). Additionally, the length of stay was shorter in patients with a UNa > 70 mmol/L (median LOS 6.2 ± 1.6 days vs. 8.5 ± 2.9 days; p=0.002).

Conclusion

Our findings suggest that UNa is a valuable tool for assessing diuretic response and guiding dosage titration in patients AHF. A UNa threshold of ≥70 mmol/L was associated with improved clinical outcomes. Conversely, a lower UNa was indicative of diuretic insufficiency and higher risk of AKI.