Dietary sodium restriction below 2 g per day predicted shorter event-free survival in patients with mild heart failure.

BACKGROUND: Despite a growing recognition that a strict low sodium diet may not be warranted in compensated heart failure (HF) patients, the link between sodium restriction below 2 g/day and health outcomes is unknown in patients at different levels of HF severity.

PURPOSE: The purpose of this study was to compare differences in event-free survival among patients with <2 g/day, 2-3 g/day, or >3 g/day sodium intake stratified by New York Heart Association (NYHA) class.

METHOD: A total of 244 patients with HF completed a four-day food diary to measure daily sodium intake. All-cause hospitalization or death for a median of 365 follow-up days and covariates on age, gender, etiology, body mass index, NYHA class, ejection fraction, total comorbidity score, the presence of ankle edema, and prescribed medications were determined by patient interview and medical record review. Hierarchical Cox hazard regression was used to address the purpose.

RESULTS: In NYHA class I/II (n=134), patients with <2 g/day sodium intake had a 3.7-times higher risk (p=0.025), while patients with >3 g/day sodium intake had a 0.4-times lower risk (p=0.047) for hospitalization or death than those with 2-3 g/day sodium intake after controlling for covariates. In NYHA class III/IV (n=110), >3 g/day sodium intake predicted shorter event-free survival (p=0.044), whereas there was no difference in survival curves between patients with <2 g/day and those with 2-3 g/day sodium intake.

CONCLUSION: Sodium restriction below 2 g/day is not warranted in mild HF patients, whereas excessive sodium intake above 3 g/day may be harmful in moderate to severe HF patients.