Adherence to a sodium-restricted diet is associated with lower symptom burden and longer cardiac event-free survival in patients with heart failure

Abstract

Aim. To determine whether adherence to a sodium-restricted diet affects symptom burden and cardiac event-free survival in patients with heart failure. Background. The recommendation of an sodium-restricted diet is a standard component of HF management. Therefore, it is important to investigate whether adherence to sodium-restricted diet is actually associated with improvements in symptom burden and cardiac event-free survival. Design. A prospective cohort study. Methods. A total of 232 patients [71% male, 65±10years, 63% New York Heart Association (NYHA) class III/IV, ejection fraction (EF) 30±9%] with HF received 24-hour urinary sodium excretion (24-hr UNa) assessments and were divided into two groups using a cut-off value of 3g 24-hr UNa. Symptom burden, including the frequency and severity of heart failure symptoms, was assessed according to the modified Memorial Symptom Assessment Scale-Heart Failure with a higher score indicating a greater symptom burden. Cardiac event-free survival over a 12-month period was determined by reviewing medical records. Results. Patients with 24-hr UNa≥3g exhibited greater symptom burdens (β=0·23, p<0·001) in hierarchical linear regression analyses and shorter cardiac event-free survival [hazard ratio=1·81, 95% confidence interval=1·17-2·80) than patients with 24-hr UNa<3g in hierarchical Cox hazards regressions, after controlling for age, gender, HF aetiology, body mass index, NYHA class, EF, and total comorbidity score. Conclusions. If sodium intake is limited to less than 3g/day, symptom burden and clinical health outcomes can be improved in HF patients. Relevance to clinical practice. Health care providers need to help patients understand the rationale for an sodium-restricted diet to prevent worsening heart failure symptoms and unnecessary cardiac events. Continuous monitoring for dietary sodium intake as well as worsening heart failure symptoms should be emphasised in patient education. © 2011 Blackwell Publishing Ltd.