Oral Sodium to Preserve Renal EfficiencY in Acute Heart Failure (OSPREY-AHF)

Dietary sodium restriction is a common therapeutic intervention in the management of patients hospitalized with decompensated heart failure. This is despite limited supportive data and inconsistent society guidelines.1-3 Randomized clinical trial data has shown that dietary sodium restriction in patients hospitalized with heart failure was not associated with differences in weight, clinical congestion, time to clinical stability but was associated with increased thirst.4 Numerous studies demonstrate that sodium restriction is associated with increased Renin-Angiotensin-Aldosterone System (RAAS) activation as well as increases in inflammatory markers.5,6 These findings challenge of the role of sodium restriction in hospital management of heart failure and have lead to trials that consider a therapeutic role of providing sodium to patients with acute heart failure for its effect in attenuating neurohormonal activation during aggressive diuresis. A central example is the SMAC-HF study from Italy, which showed that in 1771 patients with acute New York Heart Association (NYHA) class IV heart failure, the addition of hypertonic saline (150ml of 1.4%-4.6% NaCl twice a day in addition to diet liberalization led to statistically significant increased urine output and weight loss in addition to reductions in creatinine, length of stay, mortality and readmissions.7 These findings are controversial but similarly favorable results with the use of hypertonic saline in aiding diuresis have been seen in Japan with improved diuresis with continuous hypertonic saline infusions.8 Despite these results, use of sodium chloride supplementation in acute heart failure remains limited. This may be because the practice challenges ingrained clinical practice, but a more likely reason is that the manner of sodium chloride delivery in these trials (hypertonic saline) is often reserved for the Intensive Care Unit (ICU) setting and central venous access for delivery. While small volumes of hypertonic saline are likely safe to be administered in a non-ICU setting, the results would be more broadly applicable and utilized if the manner of sodium supplementation did not require intensive monitoring or central venous access, ie oral supplementation. Therefore, the purpose of the "Oral Sodium to Preserve Renal EfficiencY in Acute Heart Failure" (OSPREY-AHF) is to evaluate the efficacy and safety of oral sodium chloride supplementation compared to placebo in patients with acute decompensated heart failure. While the investigators are specifically interested in sodium chloride and its hypothesized role in attenuating a neurohormonally mediated diuretic resistance commonly seen in patients requiring high dose diuretic therapy, the investigators also intend that by focusing on oral sodium chloride supplementation the investigators may clarify the role of dietary sodium restriction in hospitalized patients with acute heart failure.