Hospital Management of Hyponatremia in Patients With Heart Failure: Interim Data from a Multi-Center Registry

Abstract

While the pathophysiology of hyponatremia (HN) in systolic heart failure (HF) is well described, little is known regarding its management in contemporary clinical practice. The goal of the ongoing “HN Registry” is to observe actual treatment and length of stay (LOS) in patients with both HF and HN in the hospital setting. Medical records were collected for patients meeting “HN Registry” criteria. Informed consent or waiver was obtained for all patients. HN was defined as a serum sodium ≤130 mmol/L. The study population includes other conditions (e.g. cirrhosis); the current interim analysis only includes patients with HF (N=537) collected over 30 months (9/2010-3/2012) at 149 US sites. Observational chart data are collected throughout the duration of the hospitalization; there is no prospective treatment algorithm or protocol. For patients on therapy for HN, LOS is calculated from the day HN is first treated. Baseline patient demographic data are shown in the figure. Baseline BNP and creatinine values are elevated. HN was first documented on day 2.4d (range 1-34). Serum sodium increased regardless of baseline GFR (GFR <30: median 2.75 mmol/L; GFR >30 <60: 2.00, GFR>60: 2.00). Many patients did not have documentation of therapy, including fluid restriction, targeting HN (N=194, 36%). Lengths of stay appeared to be longer for patients who received fluid restriction or saline infusions alone. Patients with HF and HN have elevated biomarkers and renal insufficiency but are often not treated with approaches known to lead to correction of serum sodium. Median LOS appears to vary in part by treatment. Additional data collection should permit a more accurate description of the impact of therapies on in-hospital processes and outcomes.