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.

Elevated intra-abdominal pressure: A review of current knowledge

Elevated intra-abdominal pressure (IAP) is a known cause of increased morbidity and mortality among critically ill patients. Intra-abdominal hypertension (IAH) and abdominal compartment syndrome can lead to rapid deterioration of organ function and the development of multiple organ failure. Raised IAP affects every system and main organ in the human body. Even marginally sustained IAH results in malperfusion and may disrupt the process of recovery. Yet, despite being so common, this potentially lethal condition often goes unnoticed. In 2004, the World Society of the Abdominal Compartment Syndrome, an international multidisciplinary consensus group, was formed to provide unified definitions, improve understanding and promote research in this field. Simple, reliable and nearly costless standardized methods of non-invasive measurement and monitoring of bladder pressure allow early recognition of IAH and timely optimized management. The correct, structured approach to treatment can have a striking effect and fully restore homeostasis. In recent years, significant progress has been made in this area with the contribution of surgeons, internal medicine specialists and anesthesiologists. Our review focuses on recent advances in order to present the complex underlying pathophysiology and guidelines concerning diagnosis, monitoring and treatment of this life-threatening condition.

Pathophysiology of Advanced Heart Failure: What Knowledge Is Needed for Clinical Management?

Understanding of heart failure (HF) has evolved from a simple hemodynamic problem through a neurohormonally and proinflammatory-driven syndrome to a complex multiorgan dysfunction accompanied by inadequate energy handling. This article discusses the most important clinical aspects of advanced HF pathophysiology. It presents the concept of neurohormonal activation and its deleterious effect on cardiovascular system and reflex control. The current theories regarding the role of inflammation, cytokine activation, and myocardial remodeling in HF progression are presented. Advanced HF is a multiorgan syndrome with interplay between cardiovascular system and other organs. The role of iron deficiency is also discussed.

Controlled decongestion by Reprieve therapy in acute heart failure: results of the TARGET-1 and TARGET-2 studies

AIMS

Safe and effective decongestion is the main goal of therapy in acute heart failure (AHF). In the non-randomized, prospective TARGET-1 and TARGET-2 studies (NCT03897842), we investigated whether adding the Reprieve System® (which continuously monitors urine output and delivers a matched volume of hydration fluid sufficient to maintain the set fluid balance rate) to standard diuretic-based regimen improves decongestion in AHF.

METHODS AND RESULTS

The population consisted of 19 patients hospitalized with AHF (mean age 67 ± 10 years, 18 male, ejection fraction 34 ± 15%, median N-terminal pro-B-type natriuretic peptide 4492 pg/mL). Patients served as their own controls: each patient underwent 24 h of standard diuretic therapy followed by 24 h of diuretics with Reprieve therapy (with normal saline used for matched volume replacement). The primary efficacy endpoint of actual fluid loss not exceeding the target fluid loss at the end of therapy was met in all 19 (100%) patients. The mean diuresis during Reprieve therapy was 6284 ± 2679 mL (vs. 1966 ± 1057 mL 24 h before therapy) and 2053 ± 888 mL (24 h after therapy) (both P < 0.0001). At the end of therapy, patient global assessment improved from 7.7 ± 1.1 to 3.0 ± 1.3 points (P < 0.001), central venous pressure decreased from 15.5 ± 5.3 mmHg to 12.8 ± 4.8 mmHg (P < 0.05) and the median urine sodium loss was 9.7 [3-13] mmol/h. The Reprieve therapy was safe, systolic blood pressure remained stable, mean creatinine dropped from 1.45 ± 0.4 mg/dL to 1.26 ± 0.4 mg/dL (P < 0.001) and biomarkers of renal injury did not change during treatment.

CONCLUSIONS

The Reprieve System in conjunction with diuretic therapy supports safe and controlled decongestion in AHF.

Proportional pulse pressure relates to cardiac index in stabilized acute heart failure patients

AIMS

In chronic heart failure, proportional pulse pressure (PPP) is suggested as an estimate of cardiac index (CI). The association between CI and PPP in acute heart failure (AHF) has not been described.

METHODS

This was examined using hemodynamic measurements (from a trial using serelaxin) in 63 stabilized AHF patients.

RESULTS

Mean (SD) age was 68 (11), 74% male, mean (SD) ejection fraction (EF) was 33.4% (13.7), mean (SD) CI (L/min/m²) was 2.3 (0.6). CI correlated with PPP (Pearson R = 0.42; p < 0.0001) based on a linear mixed-effects model analysis of 171 pairs of measurements from 47 patients (out of 63) where CI and PPP were measured within 3 min of each other during. Serelaxin treatment did not modify the established correlation between CI and PPP. Time-weighted average CI correlated with time-weighted average PPP (Spearman Rank R = 0.35; p = 0.0051) over the -4 h to 24 h time interval. In a multivariable regression analysis, low PPP was an independent predictor of low CI (p < 0.0001).

CONCLUSIONS

In patients with AHF after initial clinical stabilization, both baseline and post-baseline CI measurements are positively related to PPP. This was the most closely related non-invasive blood pressure variable to CI.

A randomized, double-blind, placebo-controlled, multicentre study to assess haemodynamic effects of serelaxin in patients with acute heart failure

Aims

The aim of this study was to evaluate the haemodynamic effects of serelaxin (30 µg/kg/day 20-h infusion and 4-h post-infusion period) in patients with acute heart failure (AHF).

Methods and results

This double-blind, multicentre study randomized 71 AHF patients with pulmonary capillary wedge pressure (PCWP) ≥18 mmHg, systolic blood pressure (BP) ≥115 mmHg, and estimated glomerular filtration rate ≥30 mL/min/1.73 m² to serelaxin (n = 34) or placebo (n = 37) within 48 h of hospitalization. Co-primary endpoints were peak change from baseline in PCWP and cardiac index (CI) during the first 8 h of infusion. Among 63 patients eligible for haemodynamic analysis (serelaxin, n = 32; placebo, n = 31), those treated with serelaxin had a significantly higher decrease in peak PCWP during the first 8 h of infusion (difference vs. placebo: −2.44 mmHg, P = 0.004). Serelaxin showed no significant effect on the peak change in CI vs. placebo. Among secondary haemodynamic endpoints, a highly significant reduction in pulmonary artery pressure (PAP) was observed throughout the serelaxin infusion (largest difference in mean PAP vs. placebo: −5.17 mmHg at 4 h, P < 0.0001). Right atrial pressure, systemic/pulmonary vascular resistance, and systolic/diastolic BP decreased from baseline with serelaxin vs. placebo and treatment differences reached statistical significance at some time points. Serelaxin administration improved renal function and decreased N-terminal pro-brain natriuretic peptide levels vs. placebo. Treatment with serelaxin was well tolerated with no apparent safety concerns.

Conclusion

The haemodynamic effects of serelaxin observed in the present study provide plausible mechanistic support for improvement in signs and symptoms of congestion observed with this agent in AHF patients.

ClinicalTrials.gov identifier NCT01543854.

Hyperhomocysteinemia in patients with symptomatic chronic heart failure: Prevalence and prognostic importance—pilot study

BACKGROUND

Patients with chronic heart failure (CHF) may be particularly susceptible to unfavorable effects of hyperhomocysteinemia (HHcy). The aim of this study was to assess the prevalence of HHcy (plasma homocysteine [Hcy]>or=14 micromol/L) in an unselected cohort of CHF patients, its clinical determinants, and prognostic implications.

METHODS AND RESULTS

In 108 consecutive CHF patients (81 men, age: 66+/-11 years) with mean plasma Hcy level 12.5+/-5.5 micromol/L (range 2.3-28.3 micromol/L), 38 (35%) patients demonstrated HHcy. Among clinical and metabolic parameters, in multivariable regression models, advanced NYHA class (P<0.0001), plasma NT-proBNP (P<0.001), peak oxygen consumption (P<0.05), reduced glomerular filtration rate (P<0.0001) and elevated serum uric acid (P<0.05) predicted high plasma Hcy level. HHcy was related to increased mortality (HR=3.26, 95% CI: 1.78-5.98, P=0.0001), also when adjusted for conventional prognosticators in multivariable models (all P<0.01). In patients with HHcy, a 3-year survival was 37% (95% CI: 22-52%) as compared to 73% (95% CI: 63-83%) in those with normal Hcy levels (P<0.0001).

CONCLUSIONS

HHcy is common in CHF, is related to the disease severity, depicts generalized metabolic imbalance (evidenced by hyperuricaemia), and independently predicts poor long-term prognosis.

Hyperuricaemia predicts poor outcome in patients with mild to moderate chronic heart failure

BACKGROUND

In severe chronic heart failure (CHF) elevated serum levels of uric acid (UA) predict poor survival. This study investigates whether hyperuricaemia (defined as serum UA level > or = 6.5 mg/dL) extends its prognostic value on population with less advanced CHF.

METHODS

We studied 119 consecutive patients with stable, mild-moderate CHF (88 men, age: 64+/-11 years, NYHA class I/II/III: 9/65/45, LVEF: 32+/-8%).

RESULTS

Serum UA level (mean: 6.2+/-2.0 mg/dL, range: 2.0-16.2 mg/dL) increased in parallel to CHF severity expressed as NYHA class (4.9+/-1.1 vs. 5.7+/-1.5 vs. 7.2+/-2.4 mg/dL, NYHA I vs. II vs. III; NYHA I, II vs. III, p<0.01), inversely correlated with peak oxygen consumption (r=-0.39, p<0.01) and LVEF (r=-0.31, p<0.01), but not with renal function (expressed as creatinine clearance calculated from Cockcroft-Gault formula; r=-0.14, p>0.1), and predicted inflammatory status as evidenced by the correlation with C-reactive protein (r=0.31, p=0.003). Hyperuricaemia was detected in 48 (40%) patients. During follow-up (mean: 580+/-209 days, > 18 months in all survivors), 27 (23%) patients died. Hyperuricaemia was related to impaired survival in univariate (HR 2.8, 95%CI: 1.3-6.1, p=0.01) and multivariate analyses (adjusted for NYHA class and impaired renal function--the only mortality predictors in this population; p<0.05). The 18-month survival for CHF patients with hyperuricaemia was 71% (95% CI: 58-84%) vs. 89% (95% CI: 81-96%) in those with normal UA level (p=0.01).

CONCLUSION

In patients with mild-moderate CHF, hyperuricaemia predicts exercise intolerance and inflammatory activation and is strongly and independently related to poor prognosis. Whether elevated serum UA level may become a novel therapeutic target in CHF, deserves further studies.

Effect of Darbepoetin Alfa on Exercise Tolerance in Anemic Patients With Symptomatic Chronic Heart Failure

OBJECTIVES

This study sought to investigate whether darbepoetin alfa, an erythropoiesis-stimulating protein (ESP), improves exercise capacity in patients with symptomatic chronic heart failure (CHF) and anemia.

BACKGROUND

Anemia is common in patients with CHF.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled study, CHF patients with anemia (hemoglobin > or =9.0 to < or =12.0 g/dl) received subcutaneous placebo (n = 22) or darbepoetin alfa (n = 19) at a starting dose of 0.75 microg/kg every 2 weeks for 26 weeks. The primary end point was change in exercise tolerance from baseline to week 27 as measured by peak oxygen uptake (ml/min/kg body weight). Other end points included changes in absolute peak VO2 (ml/min), exercise duration, and health-related quality of life.

RESULTS

Differences (95% confidence interval) in mean changes from baseline to week 27 between treatment groups were 1.5 g/dl (0.5 to 2.4) for hemoglobin concentration (p = 0.005), 0.5 ml/kg/min (-0.7 to 1.7) for peak VO2 (p = 0.40), 45 ml/min (-35 to 127) for absolute peak VO2 (p = 0.27), and 108 s (-11 to 228) for exercise duration (p = 0.075). Patients receiving darbepoetin alfa compared with placebo had an improvement in self-reported Patient's Global Assessment of Change (79% vs. 41%, p = 0.01) but no significant differences in the Kansas City Cardiomyopathy and Minnesota Living with Heart Failure Questionnaire scores. Darbepoetin alfa was well tolerated.

CONCLUSIONS

In patients with symptomatic CHF and anemia, darbepoetin alfa increased and maintained hemoglobin concentrations and improved health-related quality of life. A trend toward increased exercise time but not peak VO2 was observed. (Impact of Darbepoetin Alfa on Exercise Tolerance and Left Ventricular Structure in Subjects With Symptomatic Congestive Heart Failure (CHF) and Anemia; http://clinicaltrials.gov/ct/show/NCT00117234?order = 1; NCT00117234).