Dietary management of heart failure: room for improvement?

What are the outcomes of dietary interventions in Heart Failure with preserved Ejection Fraction? A systematic review and meta-analysis

AIMS

To determine the efficacy of dietary interventions in Heart Failure with preserved Ejection Fraction (HFpEF).

METHOD AND RESULTS

Keyword searches were performed in five bibliographic databases to identify randomized or controlled studies of dietary interventions conducted in HFpEF or mixed heart failure (HF) samples published in the English language. Studies were appraised for bias and synthesized into seven categories based on the similarity of the intervention or targeted population. The quality of the body of evidence was assessed via the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) framework. Twenty-five unique interventions were identified; 17 were considered for meta-analysis. Most studies were judged to be at high risk of bias. There was moderate-quality evidence that caloric restriction led to clinically meaningful improvements in blood pressure and body weight. There was moderate-quality evidence that carbohydrate restriction resulted in meaningful reductions in blood pressure. There was very low-quality evidence that protein supplementation improved blood pressure and body weight and moderate-quality evidence for clinically meaningful improvements in function.

CONCLUSIONS

While some types of dietary interventions appeared to deliver clinically meaningful change in critical outcomes; the study heterogeneity and overall quality of the evidence make it difficult to make firm recommendations. Greater transparency when reporting the nutritional composition of interventions would enhance the ability to pool studies.

REGISTRATION

PROSPERO CRD42019145388.

Heart Failure With Preserved Ejection Fraction: An Evolving Understanding

Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome in which patients have signs and symptoms of HF due to high left ventricular (LV) filling pressure despite normal or near normal LV ejection fraction. It is more common than HF with reduced ejection fraction (HFrEF), and its diagnosis and treatment are more challenging than HFrEF. Although hypertension is the primary risk factor, coronary artery disease and other comorbidities, such as atrial fibrillation (AF), diabetes, chronic kidney disease (CKD), and obesity, also play an essential role in its formation. This review summarizes current knowledge about HFpEF, its pathophysiology, clinical presentation, diagnostic challenges, current treatments, and promising novel treatments. It is essential to continue to be updated on the latest treatments for HFpEF so that patients always receive the most therapeutic treatments. The use of GnRH agonists in the management of HFpEF, infusion of Apo a-I nanoparticle, low-level transcutaneous vagal stimulation (LLTS), and estrogen only in post-menopausal women are promising strategies to prevent diastolic dysfunction and HFpEF; however, there is still no proven curative treatment for HFpEF yet.

What dietary interventions have been tested in heart failure with preserved ejection fraction? A systematic scoping review

AIMS

To determine what dietary interventions have been tested in heart failure with preserved ejection fraction (HFpEF), the modulation method, and outcomes employed and to summarize any evidence for benefit.

METHODS AND RESULTS

We performed key word searches in five bibliographic databases from 2001 to 2021, to identify randomized or experimental dietary interventions tested in HFpEF or mixed heart failure (HF) samples. Study characteristics were summarized according to population, intervention, comparator, outcome categories and intervention complexity was assessed. Twenty-five clinical investigations were retrieved; only 10 (40%) were conducted exclusively in HFpEF; the remainder enrolled mixed HF samples. Most studies employed either highly tailored prescribed diets (n = 12, 48%) or dietary supplementation (n = 10, 40%) modalities. Dietary pattern interventions (n = 3, 12%) are less well represented in the literature.

CONCLUSION

Heterogeneity made pooling studies challenging. Better reporting of baseline characteristics and the use of standardized HF lexicon would ensure greater confidence in interpretation of studies involving mixed HF populations. The field would benefit greatly from explicit reporting of the biological mechanism of action (e.g. the causal pathway) that an intervention is designed to modulate so that studies can be synthesized via their underlying mechanism of action by which diet may affect HF. An extension of the current set of core outcomes proposed by the European Society of Cardiology Heart Failure Association would ensure dietary clinical endpoints are more consistently defined and measured.

REGISTRATION

PROSPERO: CRD42019145388.

Fluid and Salt Balance and the Role of Nutrition in Heart Failure

The main challenges in heart failure (HF) treatment are to manage patients with refractory acute decompensated HF and to stabilize the clinical status of a patient with chronic heart failure. Beyond the use of medications targeted in the inhibition of the neurohormonal system, the balance of salt and fluid plays an important role in the maintenance of clinical compensation in respect of renal function. In the case of heart failure, a debate of opinion exists on salt restriction. Restricted dietary sodium might lead to worse outcomes in heart failure patients due to the activation of the neurohormonal system and malnutrition. On the contrary, positive sodium balance is the primary driver of water retention and, ultimately, volume overload in acute HF. Some recent studies reported associations of decreased salt consumption with higher readmission rates and increased mortality. Thus, the usefulness of salt restriction in heart failure management remains debated. The use of individualized nutritional support, compared with standard hospital food, was effective in reducing these risks, particularly in the group of patients at high nutritional risk.

Dietary Management of Heart Failure: DASH Diet and Precision Nutrition Perspectives

Heart failure (HF) is a major health care burden increasing in prevalence over time. Effective, evidence-based interventions for HF prevention and management are needed to improve patient longevity, symptom control, and quality of life. Dietary Approaches to Stop Hypertension (DASH) diet interventions can have a positive impact for HF patients. However, the absence of a consensus for comprehensive dietary guidelines and for pragmatic evidence limits the ability of health care providers to implement clinical recommendations. The refinement of medical nutrition therapy through precision nutrition approaches has the potential to reduce the burden of HF, improve clinical care, and meet the needs of diverse patients. The aim of this review is to summarize current evidence related to HF dietary recommendations including DASH diet nutritional interventions and to develop initial recommendations for DASH diet implementation in outpatient HF management. Articles involving human studies were obtained using the following search terms: Dietary Approaches to Stop Hypertension (DASH diet), diet pattern, diet, metabolism, and heart failure. Only full-text articles written in English were included in this review. As DASH nutritional interventions have been proposed, limitations of these studies are the small sample size and non-randomization of interventions, leading to less reliable evidence. Randomized controlled interventions are needed to offer definitive evidence related to the use of the DASH diet in HF management.

Nutrition in chronic heart failure patients: a systematic review

Nutrition is the primary source of energy production for myocardial contractility and to maintaining cardiac efficiency. Although many studies provided evidence of the benefits of nutritional intervention in chronic heart failure patients (CHF), these effects are not still completely understood. We searched in PubMed and Embase articles related to the following keywords: "chronic heart failure" with "diet," "nutrition," "insulin resistance," and "caloric restriction." Of the 975 retrieved articles, 20 have been selected. The primary endpoint was the left ventricular (LV) function and the secondary mortality rate in HF patients. Some studies showed that the Mediterranean diet (MedDiet) had a beneficial effect on cardiac function, while others did not find any positive impact. Nutritional supplements and hypercaloric intake had positive effects on underweight HF patients, while hypocaloric diet was beneficial in obese HF patients improving glucose control and cardiac function. The effect of MedDiet in HF patients showed conflicting results. Changes in the dietary pattern can reduce the evolution of HF, considering not only the quality of food but also the caloric intake. The discriminant factor to prescribe a diet regime in HF patients is represented by body mass index (BMI). A well-balanced caloric diet represents an effective therapy in overweight HF patients to reduce the mortality rate. Long-term studies evaluating cause-effect of energy and macronutrients intake on cardiac function in HF patients are necessary.

Potential Beneficial Effects of Dietary Protein Supplementation and Exercise on Functional Capacity in a Pilot Study of Individuals with Heart Failure with Preserved Ejection Fraction

Approximately half of heart failure patients in the US have heart failure with preserved ejection fraction (HFpEF). HFpEF impairs physical performance and thus reduces quality of life. Increasing dietary protein intake can increase lean body mass and physical performance in healthy elderly individuals, but the effect of a high-quality protein supplement, with or without a structured exercise program, has not been investigated in HFpEF patients. Twenty-three obese elderly HFpEF patients with grade 1 or 2 diastolic dysfunction were randomized into three groups: control, protein supplementation alone, and protein plus exercise. Protein supplementation involved providing sufficient whey protein so that total intake was 1.2 g protein/kg/day. The exercise intervention was 2 days of hydrotherapy and 1 day of gym sessions per week under supervision of a fitness expert. Physical parameters and functional tests were performed at baseline and at 12 weeks. Protein supplementation alone failed to improve physical performance. However, when combined with light exercise, there was significant improvement in some (6-minute walk, 10 m walking speed, quadriceps strength), but not all, physical function measurements. The results of this pilot study suggest that further exploration of potential interactive effects between protein supplementation and light exercise in individuals with HFpEF is warranted.

The association of the Mediterranean diet with heart failure risk in a Dutch population

BACKGROUND AND AIMS

It is still unclear whether a healthy diet can prevent heart failure (HF). Therefore, this study aimed to investigate the association between adherence to a Mediterranean-style diet, reflected by modified Mediterranean Diet Scores (mMDS), and the incidence of HF in men and women.

METHODS AND RESULTS

This observational study comprised 9316 men and 27,645 women from the EPIC-NL cohort free from cardiovascular disease at baseline. Dietary intakes were assessed using a validated food frequency questionnaire. mMDS was calculated using a 9-point scale based on consumption of vegetables, legumes, fruit, nuts, seeds, grains, fish, fat ratio, dairy, meat and alcohol. HF events were ascertained by linkage to nation-wide registries. Multivariable Hazard Ratios (HR) and 95% confidence intervals (CI) were estimated by Cox proportional hazards regression models. Over a median follow-up of 15 years (IQR 14-16), 633 HF events occurred: 144 in men (1.5%) and 489 in women (1.8%). The median mMDS was 4 (IQR 3-5). There was significant effect modification by sex (P-value for interaction <0.001), therefore results are stratified for men and women. For men, a higher mMDS associated with lower HF risk (HR: 0.88; 95% CI: 0.79, 0.98 per point increase in mMDS; HR upper category: 0.53; 95% CI: 0.33, 0.86), whereas no association was found in women (HR: 0.98; 95% CI: 0.93, 1.04 per point increase; HR upper category: 1.07; 95% CI: 0.83, 1.36).

CONCLUSION

Adherence to a Mediterranean-style diet may reduce HF risk, particularly in men. The underlying reasons for the differences in findings between men and women need further study.

Sodium Intake and Target Organ Damage in Hypertension-An Update about the Role of a Real Villain

Salt intake is too high for safety nowadays. The main active ion in salt is sodium. The vast majority of scientific evidence points out the importance of sodium restriction for decreasing cardiovascular risk. International Guidelines recommend a large reduction in sodium consumption to help reduce blood pressure, organ damage, and cardiovascular risk. Regulatory authorities across the globe suggest a general restriction of sodium intake to prevent cardiovascular diseases. In spite of this seemingly unanimous consensus, some researchers claim to have evidence of the unhealthy effects of a reduction of sodium intake, and have data to support their claims. Evidence is against dissenting scientists, because prospective, observational, and basic research studies indicate that sodium is the real villain: actual sodium consumption around the globe is far higher than the safe range. Sodium intake is directly related to increased blood pressure, and independently to the enlargement of cardiac mass, with a possible independent role in inducing left ventricular hypertrophy. This may represent the basis of myocardial ischemia, congestive heart failure, and cardiac mortality. Although debated, a high sodium intake may induce initial renal damage and progression in both hypertensive and normotensive subjects. Conversely, there is general agreement about the adverse role of sodium in cerebrovascular disease. These factors point to the possible main role of sodium intake in target organ damage and cardiovascular events including mortality. This review will endeavor to outline the existing evidence.

Emodin and emodin-rich rhubarb inhibits histone deacetylase (HDAC) activity and cardiac myocyte hypertrophy

Pathological cardiac hypertrophy is a classical hallmark of heart failure. At the molecular level, inhibition of histone deacetylase (HDAC) enzymes attenuate pathological cardiac hypertrophy in vitro and in vivo. Emodin is an anthraquinone that has been implicated in cardiac protection. However, it is not known if the cardio-protective actions for emodin are mediated through HDAC-dependent regulation of gene expression. Therefore, we hypothesized that emodin would attenuate pathological cardiac hypertrophy via inhibition of HDACs, and that these actions would be reflected in an emodin-rich food like rhubarb. In this study, we demonstrate that emodin and Turkish rhubarb containing emodin inhibit HDAC activity in vitro, with fast-on, slow-off kinetics. Moreover, we show that emodin increased histone acetylation in cardiomyocytes concomitant to global changes in gene expression; gene expression changes were similar to the well-established pan-HDAC inhibitor trichostatin A (TSA). We additionally present evidence that emodin inhibited phenylephrine (PE) and phorbol myristate acetate (PMA)-induced hypertrophy in neonatal rat ventricular myocytes (NRVMs). Lastly, we demonstrate that the cardioprotective actions of emodin are translated to an angiotensin II (Ang) mouse model of cardiac hypertrophy and fibrosis and are linked to HDAC inhibition. These data suggest that emodin blocked pathological cardiac hypertrophy, in part, by inhibiting HDAC-dependent gene expression changes.

Assessment of Dietary Habits in Patients With Chronic Heart Failure

BACKGROUND

Nutritional deficiency is a critical factor in the development and prognosis of heart failure. An optimal diet should be ensured and maintained to manage the symptoms of heart failure.

PURPOSE

This study assessed the dietary habits of patients with chronic heart failure using diet quality indices with the goal of determining their nutritional status.

METHODS

Forty-four female patients and 56 male patients (mean age: 66 ± 11.38 years) who had been admitted to the cardiology clinics of a university hospital in Istanbul between March 2012 and August 2014 were included in this study.

RESULTS

In terms of body mass index, 34% of the participants were normal weight, 37% were overweight, and 21% were obese. Furthermore, this study found the mean daily total energy intake to be inadequate and the total mean score of the Healthy Eating Index to be 74.6 ± 9.32. The diet quality of most participants fell into the "needs improvement" category.

CONCLUSIONS

This study used the Healthy Eating Index, a measure developed to assess diet quality, to assess the food consumption patterns of patients with chronic heart failure. The findings support using this index before providing diet recommendations to patients.

Dietary Patterns in Secondary Prevention of Heart Failure: A Systematic Review

BACKGROUND

Diet is an important factor in secondary prevention of heart failure (HF) but there is still no consensus as to which dietary model should be adopted by this population. This systematic review aims to clarify the relationship between dietary patterns and secondary prevention in HF.

METHODS

We searched the Medline, Embase and Cochrane databases for studies with different dietary patterns and outcomes of secondary prevention in HF. No limitation was used in the search.

RESULTS

1119 articles were identified, 12 met the inclusion criteria. Studies with Dietary Approaches to Stop Hypertension (DASH), Mediterranean, Hyperproteic and Low-carb diets were found. The DASH pattern showed improvement in cardiac function, functional capacity, blood pressure, oxidative stress and mortality. The Mediterranean diet had a correlation with inflammation, quality of life and cardiac function but just on cross-sectional studies. Regarding the Hyperproteic and Low-carb diets only one study was found with each pattern and both were able to improve functional capacity in patients with HF.

CONCLUSIONS

DASH pattern may have benefits in the secondary prevention of HF. The Mediterranean diet demonstrated positive correlation with factors of secondary prevention of HF but need more RCTs and cohort studies to confirm these effects. In addition, the Hyperproteic and Low-carb diets, despite the lack of studies, also demonstrated positive effects on the functional capacity in patients with HF.

Dietary Self-management in Heart Failure: High Tech or High Touch?

OPINION STATEMENT

Dietary management of heart failure (HF) has largely been focused on sodium and fluid restrictions. Although safety and efficacy of these interventions in HF remain unclear, a daily sodium intake between 2000 and 3000 mg/day appears to be safe in these patients. Ongoing clinical research will inform on the safety and efficacy of a more restrictive sodium intake to less than 1500 mg/day. Data shows that routine fluid restriction in HF regardless of symptoms may be unnecessary; however, in patients with signs of congestion, fluid restriction to 2.0 L/day may be advisable. Recently, more attention has been paid to other nutritional aspects of HF beyond sodium and fluid intake, although there is still little evidence available to guide nutritional management of HF. Assuring that patients meet daily requirements for key micronutrients, such as calcium, magnesium, potassium, folate, vitamin E, vitamin D, zinc, and thiamine, is essential in order to prevent deficiencies. More appropriate macronutrient composition of the diet is still to be determined; however, a diet containing 50-55% carbohydrates, 25-30% fat, and 15-20% protein seems acceptable for patients with HF with or without non-end-stage renal disease. Additionally, increased protein intake may be considered in malnourished/cachectic patients. Consulting a registered dietitian is especially helpful for patients with recent HF exacerbations or for patients with multiple comorbidities who may need to follow several dietary restrictions and may benefit of individualized dietary counseling in order to ensure appropriate intake of energy, protein, and micronutrients. Today, there are still several knowledge gaps in guiding the dietary management of HF. In this article, we review current recommendations for the dietary management of HF and the evidence supporting this practice.