Background
Dietary restriction of sodium has been suggested to prevent fluid overload and adverse
outcomes for patients with heart failure. We designed the Study of Dietary Intervention
under 100 mmol in Heart Failure (SODIUM-HF) to test whether or not a reduction in
dietary sodium reduces the incidence of future clinical events.
Methods
patients at 26 sites in six countries (Australia, Canada, Chile, Colombia, Mexico,
and New Zealand). Eligible patients were aged 18 years or older, with chronic heart
failure (New York Heart Association [NYHA] functional class 2–3), and receiving optimally
tolerated guideline-directed medical treatment. Patients were randomly assigned (1:1),
using a standard number generator and varying block sizes of two, four, or six, stratified
by site, to either usual care according to local guidelines or a low sodium diet of
less than 100 mmol (ie, ClinicalTrials.gov, NCT02012179, and is closed to accrual.
Findings
Between March 24, 2014, and Dec 9, 2020, 806 patients were randomly assigned to a
low sodium diet (n=397) or usual care (n=409). Median age was 67 years (IQR 58–74)
and 268 (33%) were women and 538 (66%) were men. Between baseline and 12 months, the
median sodium intake decreased from 2286 mg/day (IQR 1653–3005) to 1658 mg/day (1301–2189)
in the low sodium group and from 2119 mg/day (1673–2804) to 2073 mg/day (1541–2900)
in the usual care group. By 12 months, events comprising the primary outcome had occurred
in 60 (15%) of 397 patients in the low sodium diet group and 70 (17%) of 409 in the
usual care group (hazard ratio [HR] 0·89 [95% CI 0·63–1·26]; p=0·53). All-cause death
occurred in 22 (6%) patients in the low sodium diet group and 17 (4%) in the usual
care group (HR 1·38 [0·73–2·60]; p=0·32), cardiovascular-related hospitalisation occurred
in 40 (10%) patients in the low sodium diet group and 51 (12%) patients in the usual
care group (HR 0·82 [0·54–1·24]; p=0·36), and cardiovascular-related emergency department
visits occurred in 17 (4%) patients in the low sodium diet group and 15 (4%) patients
in the usual care group (HR 1·21 [0·60–2·41]; p=0·60). No safety events related to
the study treatment were reported in either group.
Interpretation
In ambulatory patients with heart failure, a dietary intervention to reduce sodium
intake did not reduce clinical events.
Funding
Canadian Institutes of Health Research and the University Hospital Foundation, Edmonton,
Alberta, Canada, and Health Research Council of New Zealand.