In relation to natriuresis in the pathophysiology of heart failure, current guidelines focus on fluid balance and weight change. Despite the frequent use of these parameters as endpoints in major clinical trials, they have yet to be linked to meaningful clinical outcomes. Researchers in the ROSE-AHF trial suggest that this focus on fluid volume and weight change represents a flawed approach that fails to directly address the balance of sodium in the body — and its effect on outcomes.
In the ROSE-AHF trial, Hodson et al. evaluated sodium excretion in a group of hospitalized patients with acute decompensated heart failure (ADHF) treated with high-dose loop diuretic therapy, and found sodium excretion to be highly variable — both across patients, and within the same patient on different days. They further found that over a three-day assessment period, a considerable percentage (~29%) of participants showed a positive sodium balance (i.e. they excreted less sodium than they consumed), while fewer had a positive fluid balance (8.2%) or weight gain (15.8%).
Data show that this positive sodium balance was significantly associated with decreased 6-month survival (p=0.03), while a positive fluid balance (p=0.57) and weight gain (p=0.44) were not. More importantly, survival at 6 months was also less in the 23% of patients who experienced net fluid loss over the assessment period but had positive sodium balance (p=0.01).
This suggests that sodium balance is a critical variable that carries significant prognostic value, and could ultimately prove to be a viable alternative to urine output and fluid balance to guide diuretic therapy in ADHF.
Original article: JACC Heart Fail. 2019;7:383-91
Author: Daniel Guns, Cardiology Update