Three gram sodium intake is associated with longer event-free survival only in patients with advanced heart failure

Background: There is limited evidence to support the recommendation that patients with heart failure (HF) restrict sodium intake. The purpose of this study was to compare differences in cardiac event-free survival between patients with sodium intake above and below 3 g. Methods: A total of 302 patients with HF (67% male, 62 ± 12 years, 54% New York Heart Association [NYHA] Class III/IV, ejection fraction 34 ± 14%) collected a 24-hour urine sodium (UNa) to indicate sodium intake. Patients were divided into 2 groups using a 3-g UNa cutpoint and stratified by NYHA Class (I/II vs. III/IV). Event-free survival for 12 months was determined by patient or family interviews and medical record review. Differences in cardiac event-free survival were determined by Kaplan-Meier survival curve with log-rank test and Cox hazard regression. Results: The Cox regression hazard ratio for 24-hour UNa ≥ 3 g in NYHA Class I/II was 0.44 (95% confidence interval [CI] = 0.20-0.97) and 2.54 (95% CI = 1.10-5.84) for NYHA III/IV after controlling for age, gender, HF etiology, body mass index, ejection fraction, and total comorbidity score. Conclusions: These data suggest that 3 g dietary sodium restriction may be most appropriate for patients in NYHA functional Classes III and IV.