Post-diuretic spot urine sodium assessment in acute heart failure: a retrospective analysis

ABSTRACT

Aims

To provide real-world data on post-diuretic spot urine sodium concentration (UNa) assessment in acute heart failure (AHF) and its implications for treatment.

Methods and Results

Automated query of the electronic medical record identified patients admitted to the cardiac intensive care unit of a single tertiary care hospital between November 2018 and December 2021, who received intravenous loop diuretics. Detailed manual chart review confirmed the AHF diagnosis. Stratification was performed based on whether post-diuretic UNa was assessed within 24 h of admission. AHF was confirmed in 340/380 identified patients. Post-diuretic UNa was assessed in 117 (34%), more frequently when ejection fraction was reduced and heart failure more advanced. Patients with versus without post-diuretic UNa assessment received higher doses of intravenous loop diuretics and more frequently acetazolamide and thiazide-like diuretics (p < 0.001 for all), resulting in similar urine output despite more advanced heart failure [2,488 mL (1,740-4,033 mL) vs. 2,400 mL (1,553-3,250 mL), respectively; p = 0.170]. Diuretic therapy remained more intense at discharge in the post-diuretic UNa group, with also a higher prescription rate of angiotensin-neprilysin inhibitors (p = 0.021). Serum creatinine increases/decreases were similarly frequent irrespectively from UNa assessment, with more dynamic changes observed in patients with UNa ≤ 80 mmol/L versus ≥ 81 mmol/L. After adjustments for baseline characteristics, the risk for death or heart failure readmission was similar in patients with versus without UNa assessment [HR (95%CI) = 1.43 (0.88-2.32); p = 0.150].

Conclusion

Post-diuretic UNa assessment in AHF was associated with more intense diuretic regimens, preserving urine output despite its use in a sicker population.

KEYWORDS:

• Cardiac edema
• diuretics
• heart failure
• natriuresis
• urine specimen collection

Abbreviations

AHF, acute heart failure; eGFR, estimated glomerular filtration rate; IRF, improved renal function; NTproBNP, N-terminal of prohormone Btype natriuretic peptide; UNa, urine sodium concentration; WRF, worsening renal function.

Acknowledgments

The authors wish to thank the nursing team from the cardiac intensive care unit in University Hospital Brussels for collecting the urine samples in so many patients.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Raw data are available upon reasonable request to the corresponding author.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/17843286.2024.2341193