Urine sodium in acute heart failure: Time for reappraisal

Abstract

Congestion is the primary reason for hospital admission in patients with acute heart failure and is the key target of therapy in this setting. Urine sodium excretion has emerged as an objective and clinically relevant marker of response to decongestive therapies that portend prognostic value. While diuretics remain the mainstay of therapy in these patients, a significant subset of them experiences suboptimal response (e.g. diuretic resistance) and lingering congestion that is known to be associated with adverse outcomes. Herein, we provide an overview of several strategies that have been explored to enhance urinary sodium excretion, with the goal of improving congestion and possibly the overall outcomes. While some of these options have had suboptimal results (e.g. dopamine), the preliminary data on other methods seem to be encouraging (e.g. hypertonic saline solution). Sequential nephron blockade of sodium absorption is a widely used option that has had several advancements in recent years especially with new clinical trials targeting proximal tubular sodium absorption (e.g. sodium-glucose cotransporter-2 inhibitors). While kidney-sparing mechanical extraction of sodium (ultrafiltration therapy) is being actively investigated, several other trials focusing on natriuresis-guided decongestive therapy are on the way. The findings of these studies are expected to help clinicians refine current strategies to further enhance urinary sodium excretion and decongestion.