Reduced Dietary Sodium in Heart Failure Patients Had Little Impact on Clinical Events: SODIUM-HF

April 2, 2022

Conference | ACC

ACC 2022. SODIUM-HF secondary findings, however, showed improvement in NYHA HF class and in QOL in the dietary intervention group.

Among a large group of patients with heart failure (HF), a reduction in dietary sodium slowed disease progression and improved quality of life (QOL) although the intervention did not reduce the incidence of clinical events or hospitalizations, report authors of the SODIUM-HF trial who presented their findings at the American College of Cardiology’s (ACC) 71st Annual Scientific Session.

SODIUM-HF, reported to be the largest and longest randomized clinical trial to examine sodium restriction for HF, fell short of meeting its primary endpoint—a composite of all-cause death and cardiovascular (CV) hospitalizations or emergency department (ED) visits. However, improvements in secondary outcomes, the researchers said, suggest limiting sodium may be beneficial for some HF patients.

“While the intervention didn’t reduce clinical events, we found the low-sodium group had modest improvements in quality of life and New York Heart Association heart failure class, which we think will be quite important and valued by patients and clinicians alike,” said lead study author Justin A Ezekowitz, MBBCh, professor of medicine at the University of Alberta, Edmonton in Canada in an ACC press release. “We need to explore further whether there might be a way to individualize recommendations from our trial to see if the quality-of-life benefits might make it worth it for certain patients [to reduce sodium intake].”

Limited evidence for low sodium

Patients with HF, even when receiving medical and device therapy, remain at high risk for future events and hospitalization, said SODIUM-HF investigators in the study abstract. And while dietary sodium reduction is frequently recommended, evidence for the association of lower salt intake with reduced HF-associated morbidity and mortality is limited.

To build the knowledge base, Ezekowitz and colleagues conducted SODIUM-HF, a pragmatic, randomized multicenter open-label trial, in 26 medical centers across 6 countries. The investigators enrolled 841 patients being treated for HF regardless of ejection fraction.

Patients were randomized 1:1 to receive either usual care for HF or a counseling intervention designed to reduce daily sodium intake to <1500 mg. Trained counselors provided individual nutritional guidance based on review of frequently collected 3-day food records that were also used to calculate daily sodium intake.

Investigators defined the primary endpoint as a composite of occurrence of CV-related hospitalization, CV-related ED visit, or death from any cause within 1 year after patient randomization. The 2 secondary endpoints of interest were change in patient quality of life (QOL) as measured with the 12-question Kansas City Cardiomyopathy Questionnaire (KCCQ-12), change in New York Heart Association (NYHA) HF class, and change in 6-minute walk test (6MWT).

The 841 patients enrolled had a median age of 67 years and 33% were women; 47% had coronary artery disease and 41% had atrial fibrillation. The median left ventricular ejection fraction was 36%. Baseline medium sodium intake was 2217 mg across both groups.

RESULTS

At the 6-month mark, median daily sodium intake in the intervention group was 1651 mg and 2052 in the usual care group. At 1 year, values were 1658 and 2072, respectively.

When Ezekowitz and colleagues analyzed the data at 1 year, the total number of primary outcome events was numerically lower in the nutritional intervention group vs the usual care group, but the result did not reach statistical significance.

When they looked at secondary outcomes, the investigators found significant improvements in QOL scores in the intervention group vs usual care group across 3 validated instruments, improvements that remained consistent across all assessments and across time, said Ezekowitz in the ACC statement. The improvement, he added, was "quite marked compared to other clinical trials" including trials for pharmacologic interventions.

A further bright spot was an improvement in NYHA HF class among participants in the intervention group; however, there was no change noted in 6MWT.

Commenting on future research, lead author Ezekowitz said that further studies are required to determine whether an even greater reduction in sodium intake might affect health outcomes in HF patients or whether level of benefit may be affected by disease severity and individual QOL. After noting that a longer follow-up period could potentially reveal longer-term differences in outcomes, he said that his team plans to continue the study and assess outcomes at 24 months.

This study was simultaneously published online in The Lancet at the time of presentation on Saturday, April 2. 2022

Ezekowitz JA, SODIUM-HF investigators. SODIUM-HF: Study of dietary intervention under 100 mmol in heart failure.