Sodium Restriction in Patients With Heart Failure: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

The role of exercise training and dietary sodium restriction in heart failure rehabilitation: A systematic review

Heart failure (HF) rehabilitation seeks to enhance the entire well-being and quality of life of those with HF by focusing on both physical and mental health. Non-pharmacological measures, particularly exercise training, and dietary salt reduction, are essential components of heart failure rehabilitation. This study examines the impact of these components on the recovery of patients with heart failure. By conducting a comprehensive analysis of research articles published from 2010 to 2024, we examined seven relevant studies collected from sources that include PubMed and Cochrane reviews. Our findings indicate that engaging in physical activity leads to favorable modifications in the heart, including improved heart contractility, vasodilation, and cardiac output. These alterations enhance the delivery of oxygen to the peripheral tissues and reduce symptoms of heart failure, such as fatigue and difficulty breathing. Nevertheless, decreasing the consumption of salt in one's diet to less than 1500 mg per day did not have a substantial impact on the frequency of hospitalizations, visits to the emergency room, or overall mortality when compared to conventional treatment. The combination of sodium restriction and exercise training can have synergistic effects due to their complementary modes of action. Exercise improves cardiovascular health and skeletal muscle metabolism, while sodium restriction increases fluid balance and activates neurohormonal pathways. Therefore, the simultaneous usage of both applications may result in more significant enhancements in HF symptoms and clinical outcomes compared to using each program alone.

Salt versus no salt restriction in heart failure a review

BACKGROUND

For decades standard teaching recommended salt intake (sodium) reduction in patients suffering from heart failure. Neurohumoral activation with subsequent fluid retention provided a solid rationale for this long-standing recommendation. Until recently no large randomized clinical trial of sodium restriction was available, while some observational studies and metanalyses even suggested a worse outcome with strict sodium restriction in patients with heart failure.

METHODS

In this narrative review we aimed to extricate from the literature whether strict sodium restriction is beneficial in patients with heart failure. We searched PubMed indexed articles between 2000 and 2023 for these terms: heart failure, salt, sodium, fluid intake.

RESULTS

Most randomized trials were small and showed a wide heterogeneity of interventions. A single large, randomized clinical trial was stopped early due to futility. Overall, there is no evidence that severe sodium restriction reduces the incidence of mortality and hospitalization in patients with heart failure. Quality of life and functional class may improve slightly with sodium restriction.

CONCLUSION

Morbidity and mortality are not reduced with sodium restriction in patients with heart failure, although some symptomatic improvement may be expected.

Renal Sodium Avidity in Heart Failure

BACKGROUND

Increased renal sodium avidity is a hallmark feature of the heart failure syndrome.

SUMMARY

Increased renal sodium avidity refers to the inability of the kidneys to elicit potent natriuresis in response to sodium loading. This eventually causes congestion, which is a major contributor to hospital admissions and mortality in heart failure.

KEY MESSAGES

Important novel concepts such as the renal tamponade hypothesis, accelerated nephron loss, and the role of hypochloremia, the sympathetic nervous system, inflammation, the lymphatic system, and interstitial sodium buffers are involved in the pathophysiology of renal sodium avidity. A good understanding of these concepts is crucially important with respect to treatment recommendations regarding dietary sodium restriction, fluid restriction, rapid up-titration of guideline-directed medical therapies, combination diuretic therapy, natriuresis-guided diuretic therapy, use of hypertonic saline, and ultrafiltration.

Dietary sodium and fluid intake in heart failure. A clinical consensus statement of the Heart Failure Association of the ESC

Sodium and fluid restriction has traditionally been advocated in patients with heart failure (HF) due to their sodium and water avid state. However, most evidence regarding the altered sodium handling, fluid homeostasis and congestion-related signs and symptoms in patients with HF originates from untreated patient cohorts and physiological investigations. Recent data challenge the beneficial role of dietary sodium and fluid restriction in HF. Consequently, the European Society of Cardiology HF guidelines have gradually downgraded these recommendations over time, now advising for the limitation of salt intake to no more than 5 g/day in patients with HF, while contemplating fluid restriction of 1.5-2 L/day only in selected patients. Therefore, the objective of this clinical consensus statement is to provide advice on fluid and sodium intake in patients with acute and chronic HF, based on contemporary evidence and expert opinion.

Sodium loading in ambulatory patients with heart failure with reduced ejection fraction: Mechanistic insights into sodium handling

AIMS

Sodium restriction was not associated with improved outcomes in heart failure patients in recent trials. The skin might act as a sodium buffer, potentially explaining tolerance to fluctuations in sodium intake without volume overload, but this is insufficiently understood. Therefore, we studied the handling of an increased sodium load in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Twenty-one ambulatory, stable HFrEF patients and 10 healthy controls underwent a 2-week run-in phase, followed by a 4-week period of daily 1.2 g (51 mmol) sodium intake increment. Clinical, echocardiographic, 24-h urine collection, and bioelectrical impedance data were collected every 2 weeks. Blood volume, skin sodium content, and skin glycosaminoglycan content were assessed before and after sodium loading. Sodium loading did not significantly affect weight, blood pressure, congestion score, N-terminal pro-brain natriuretic peptide, echocardiographic indices of congestion, or total body water in HFrEF (all p > 0.09). There was no change in total blood volume (4748 ml vs. 4885 ml; p = 0.327). Natriuresis increased from 150 mmol/24 h to 173 mmol/24 h (p = 0.024), while plasma renin decreased from 286 to 88 μU/L (p = 0.002). There were no significant changes in skin sodium content, total glycosaminoglycan content, or sulfated glycosaminoglycan content (all p > 0.265). Healthy controls had no change in volume status, but a higher increase in natriuresis without any change in renin.

CONCLUSIONS

Selected HFrEF patients can tolerate sodium loading, with increased renal sodium excretion and decreased neurohormonal activation.

The current state of evidence for sodium and fluid restriction in heart failure

The field of heart failure has evolved in terms of the therapies that are available including pharmaceutical and device therapies. There is now substantial randomized trial data to indicate that dietary sodium restriction does not provide the reduction in clinical events with accepted heterogeneity in the clinical trial results. Dietary sodium restriction should be considered for some but not all patients and with different objectives than clinical outcomes but instead for potential quality of life benefit. In addition, fluid restriction, once the mainstay of clinical practice, has not shown to be of any additional benefit for patients in hospital or in the ambulatory care setting and therefore should be considered to be used cautiously (if at all) in clinical practice. Further developments and clinical trials are needed in this area to better identify patients who may benefit or have harm from these lower cost interventions and future research should focus on large scale, high quality, clinical trials rather than observational data to drive clinical practice.

The Prognostic Value and Treatment Strategies of Nutritional Status in Heart Failure Patients

Heart failure is a complex clinical syndrome caused by a variety of reasons leading to abnormal changes in the structure and/or function of the heart, with ventricular systolic and/or diastolic dysfunction, which is a serious manifestation or late stage of various heart diseases. The overall prognosis of patients is poor, and risk assessment of patients with HF is currently a hot topic of research due to the large heterogeneity of etiology, phenotype, and genetic background of HF patients. Besides, the nutritional level and status of HF patients are affected by various aspects. Patients with malnutrition, high saturated fatty acids and cholesterol, low minerals, and other conditions tend to have a poor prognosis. So targeted improvement of the nutritional status of HF patients is important to improve the prognosis and the quality of survival of patients. We use heart failure, nutrition, and diet therapy as the keyword method to summarize the prognostic value of indicators of nutritional status in HF patients, the effects of nutritional status on HF patients with different etiology, and potential treatment strategies for HF patients with different etiology. This review is valuable for understanding the prognostic value of nutritional levels in patients with HF and guiding clinical therapeutic approaches.

Optimization of guideline-directed medical treatment for heart failure patients with reduced ejection fraction

With the increasing number of medications demonstrating mortality benefits in heart failure with reduced ejection fraction (HFrEF), the pharmacological treatment of HFrEF is entering a new phase. To enhance outcomes in heart failure patients through medical treatment, the choice of appropriate medications and simultaneous and rapid uptitration are critical. However, there are several challenges encountered during this medication uptitration, including issues like hypotension, fatigue, worsening renal function, and hyperkalemia. This paper addresses strategies for effectively managing these challenges to successfully reach the maximum tolerated dose in patients. Additionally, it will discuss the management of comorbidities often associated with heart failure, the importance of exercise and rehabilitation, and the significance of proper nutrition intake, in addition to guideline-directed medical therapy.

Role of dietary sodium restriction in chronic heart failure: systematic review and meta-analysis

BACKGROUND

Dietary sodium restriction remains a guidelines-approved lifestyle recommendation for chronic heart failure (CHF) patients. However, its efficacy in clinical outcome improvement is dubious.

OBJECTIVE

The study evaluated whether dietary sodium restriction in CHF reduces clinical events.

METHODS

We performed a systematic review of the following databases: Academic Search Ultimate, ERIC, Health Source Nursing/Academic Edition, MEDLINE, Embase, Clinicaltrials.gov and Cochrane Library (trials) to find studies analysing the impact of sodium restriction in the adult CHF population. Both observational and interventional studies were included. Exclusion criteria included i.e.: sodium consumption assessment based only on natriuresis, in-hospital interventions or mixed interventions-e.g. sodium and fluid restriction in one arm only. The review was conducted following PRISMA guidelines. Meta-analysis was performed for the endpoints reported in at least 3 papers. Analyses were conducted in Review Manager (RevMan) Version 5.4.1.

RESULTS

Initially, we screened 9175 articles. Backward snowballing revealed 1050 additional articles. Eventually, 9 papers were evaluated in the meta-analysis. All-cause mortality, HF-related hospitalizations and the composite of mortality and hospitalisation were reported in 8, 6 and 3 articles, respectively. Sodium restriction was associated with a higher risk of the composite endpoint (OR 4.12 [95% CI 1.23-13.82]) and did not significantly affect the all-cause mortality (OR 1.38 [95% CI 0.76-2.49]) or HF hospitalisation (OR 1.63 [95% CI 0.69-3.88]).

CONCLUSIONS

In a meta-analysis, sodium restriction in CHF patients worsened the prognosis in terms of a composite of mortality and hospitalizations and did not influence all-cause mortality and HF hospitalisation rate.