Lowering Salt Intake Found to Have Mixed Results in Patients With Heart Failure

Data from the largest randomized clinical trial to date showed mixed results from the impact of lowering sodium intake on heart failure, according to findings presented at the American College of Cardiology 71st Annual Scientific Session.

Lowering salt intake was not found to reduce visits to the emergency department (ED), rates of hospitalizations, or mortality among patients with heart failure. However, there were improvements in symptoms such as swelling, fatigue, and coughing, as well as improved overall quality of life, according to the study, the results of which were also published in The Lancet.

“We can no longer put a blanket recommendation across all patients and say that limiting sodium intake is going to reduce your chances of either dying or being in hospital, but I can say comfortably that it could improve people's quality of life overall,” lead author Justin Ezekowitz, professor in the University of Alberta’s Faculty of Medicine & Dentistry and co-director of the Canadian VIGOUR Centre, said in a statement.

For the study, investigators analyzed 806 patients across 26 medical centers in Canada, the United States, Columbia, Chile, Mexico, and New Zealand, all of whom had heart failure. Half of those in the study were randomly assigned to receive usual care, whereas the other patients were given nutritional counseling to lower their dietary salt intake.

Patients in the nutritional counseling cohort received dietitian-designed menu suggestions based on the region in which they reside and were encouraged to prepare their own meals without adding salt while avoiding high-salt ingredients. Target sodium intake was 1500 mg per day, which is equal to approximately two-thirds of a teaspoon of salt.

“The broad rule that I've learned from dietitians is that anything in a bag, a box or a can generally has more salt in it than you would think,” Ezekowitz said.

Prior to the study, patients consumed an average of just under 1 teaspoon of salt per day. After 1 year, the usual care group was found to consume an average of 2072 mg of sodium daily, whereas patients who received nutritional guidance consumed 1658 mg per day. This translated to a decrease slightly less than one-quarter teaspoon equivalent.

The investigators then evaluated rates of death from any cause, cardiovascular hospitalization, and cardiovascular ED visits among both cohorts, which did not achieve a difference that was deemed statistically significant.

The low-sodium cohort was found to have significant improvements across 3 different quality of life assessment tools and via New York Heart Association heart failure classification.

Ezekowitz noted that he will continue to advise patients with heart failure to lower their sodium intake; however, he will be clear about the anticipated benefits. He added that health care providers should recognize how useful dietary changes can be for some patients.

The study authors announced plans to conduct additional research to isolate a marker in the blood from patients who gained the greatest benefit from a low-sodium diet in hopes of providing more targeted individual diet prescriptions in the future. They also plan to follow up with the trial patients at 24 months and 5 years to evaluate any long-term benefits.