Again, this is a meta-analysis (if you don't know what that means please google it) so the conclusions need to be thought about in that context (not a controlled, double blind trial):http://heart.bmj.com/content/early/2012/08/21/heartjnl-2012-302337.abstractLow sodium versus normal sodium diets in systolic heart failure: systematic review and meta-analysisAbstract
Context A low sodium diet has been proposed to reduce the risk of heart failure (HF) hospitalisations and is currently advocated in consensus guidelines, yet some evidence suggests adverse neurohumoral activation for sodium restriction in the HF setting.Objectives
To evaluate the effects of a restricted sodium diet in patients with systolic HF.Data sources
A systematic review and meta-analysis of randomised trials OVID MEDLINE, PubMed, Excerpta Medica (Embase), the Cochrane Controlled Trials Register, Scopus, Web of Science and Google Scholar were searched up to April 2012.Study selection
Two independent reviewers selected studies for inclusion on the basis of a randomised controlled trial design that included adults with systolic HF receiving a restricted salt diet or control diet and reporting mortality (all-cause, sudden death or HF-related) and HF-related hospitalisations.Data extraction and analysis
Descriptive and quantitative information was extracted from included studies. A random-effects model was used to compute pooled risk ratios (RR) for mortality and morbidity outcomes.Results
Six randomised trials comparing low sodium diets (1.8 g/day) with normal sodium diets (2.8 g/d) in 2747 patients with systolic HF were identified. Compared with a normal sodium diet, a low sodium diet significantly increased all cause mortality (RR 1.95, 95% CI 1.66 to 2.29), sudden death (RR 1.72, 95% CI 1.21 to 2.44), death due to HF (RR 2.23, 95% CI 1.77 to 2.81) and HF readmissions (RR 2.10, 95% CI 1.67 to 2.64).Conclusion
Compared with a normal sodium diet, a low sodium diet significantly increases morbidity and mortality in systolic HF.