Serial assessment of spot urine sodium predicts effectiveness of decongestion and outcome in patients with acute heart failure

Abstract

Aims The clinical significance of the measurement of urine sodium concentration (UNa+) in response to loop diuretic administration in patients with acute heart failure (AHF) is still unsettled. We studied the association of serial measurements of spot UNa+ during the first 48 h of AHF treatment with the indices of decongestion, renal function, and prognosis. Methods and results We enrolled 111 AHF patients, all of whom received intravenous furosemide on admission. The mean spot UNa+ significantly increased in the 6 h sample (P < 0.05 vs. baseline) and returned to baseline values in the 24 and 48 h samples. Based on the increase or decrease/no change of UNa+ in the 6 and 48 h samples vs. baseline, patients were divided into two groups at each time point, respectively. Patients did not differ in baseline clinical and laboratory characteristics. Patients with a decrease/no change of UNa+ in the 6 and 48 h samples had a lower weight loss during hospitalization. Patients with a decrease/no change of UNa+ in the 48 h sample had a poorer diuretic response and a significant increase in the urinary levels of the tubular biomarkers: kidney injury molecule‐1 and neutrophil gelatinase‐associated lipocalin. Low UNa+ and decrease/no change in UNa+ in the 6 and 48 h samples were independent predictors of higher risk of all‐cause mortality during 1‐year follow‐up (all P < 0.05). Conclusion In AHF, low spot UNa+ and lack to increase UNa+ in response to intravenous diuretics are associated with poor diuretic response, markers of tubular injury and high risk of 1‐year mortality.

Hepatorenal dysfunction identifies high‐risk patients with acute heart failure: insights from the RELAX‐AHF trial

“…These findings confirm the previous observation that serelaxin demonstrated end-organ protective effects in AHF, but most likely, it was restricted only to a period of active drug infusion. [38][39][40][41] In the future, we will probably use a multimarket approach to assess a single organ as well as interplay between organs. 23,25 Lastly, the biological importance of kidney and liver function is far more complex than can be assessed by measurement of creatinine and bilirubin.…”

“…Thus, novel and promising markers of organ dysfunction as a result of heart failure severity have been proposed, like the assessment of liver stiffness (a marker related to congestion and liver remodelling as a result of congestion), assessment of urine sodium (a marker of renal water-sodium handling in heart failure), or serum osmolarity. [38][39][40][41] In the future, we will probably use a multimarket approach to assess a single organ as well as interplay between organs.…”

Evaluation of kidney function throughout the heart failure trajectory – a position statement from the Heart Failure Association of the European Society of Cardiology

“…Evaluation of diuretic response (also termed diuretic efficiency) has gained a lot of interest lately . Indeed, heart failure is characterized by a very early loss in natriuretic responsiveness, which contributes to development of congestion .…”

“…Hereby allowing the clinician to interpret diuretic response and generating the opportunity to intervene early if sodium concentration is low. In the face of congestion with volume overload, a spot urine sodium concentration of <50–70 mEq/L after 2 h, and/or an hourly urine output <100–150 mL during the first 6 h, generally identifies a patient with an insufficient diuretic response . However, irrespective of the metric used, all data indicate that a good diuretic response is associated with a better prognosis.…”

Controlled decongestion by Reprieve therapy in acute heart failure: results of the TARGET‐1 and TARGET‐2 studies

“…This was associated with net negative fluid balance accompanied by an increase in UNa + concentration during treatment. Indeed, we observed a trajectory of increasing natriuresis within the first 6 h of treatment, which seems to be an early prognosticator for effective diuretic response and decongestion and possibly better outcomes . Moreover, we observed a significant increase of serum sodium and serum osmolality after 24 h of therapy, likely suggesting improvement of water/sodium handling, which is a well known factor of good prognosis in heart failure .…”