Social and environmental risks as contributors to the clinical course of heart failure.

Heart failure is a major contributor to healthcare expenditures. Many clinical risk factors for the development and exacerbation of heart failure had been reported, including diabetes, renal dysfunction, and respiratory disease. In addition to these clinical parameters, the effects of social factors, such as occupation or lifestyle, and environmental factors may have a great impact on disease development and progression of heart failure. However, the current understanding of social and environmental factors as contributors to the clinical course of heart failure is insufficient. To present the knowledge of these factors to date, this comprehensive review of the literature sought to identify the major contributors to heart failure within this context. Social factors for the risk of heart failure included occupation and lifestyle, specifically in terms of the effects of specific occupations, occupational exposure to toxicities, work style, and sleep deprivation. Socioeconomic factors focused on income and education level, social status, the neighborhood environment, and marital status. Environmental factors included traffic and noise, air pollution, and other climate factors. In addition, psychological stress and behavior traits were investigated. The development of heart failure may be closely related to these factors; therefore, these data should be summarized for the context to improve their effects on patients with heart failure. The present study reviews the literature to summarize these influences.

Synthesis and evaluation of trypanocidal activity of derivatives of naturally occurring 2,5-diphenyloxazoles.

African trypanosomiasis is a zoonotic protozoan disease affecting the nervous system. Various natural products reportedly exhibit trypanocidal activity. Naturally occurring 2,5-diphenyloxazoles present in Oxytropis lanata, and their derivatives, were synthesized. The trypanocidal activities of the synthesized compounds were evaluated against Trypanosoma brucei brucei, T. b. gambiense, T. b. rhodesiense, T. congolense, and T. evansi. Natural product 1 exhibited trypanocidal activity against all the species/subspecies of trypanosomes, exhibiting half-maximal inhibitory concentrations (IC50) of 1.1-13.5 µM. Modification of the oxazole core improved the trypanocidal activity. The 1,3,4-oxadiazole (7) and 2,4-diphenyloxazole (9) analogs exhibited potency superior to that of 1. However, these compounds exhibited cytotoxicity in Madin-Darby bovine kidney cells. The O-methylated analog of 1 (12) was non-cytotoxic and exhibited selective trypanocidal activity against T. congolense (IC50 = 0.78 µM). Structure-activity relationship studies of the 2,5-diphenyloxazole analogs revealed aspects of the molecular structure critical for maintaining selective trypanocidal activity against T. congolense.

Association between infectious event and de novo malignancy after heart transplantation.

The aim of the study was to investigate the incidence of and risk factors for de novo malignancy after heart transplantation (HTx) in a single center. We assessed 102 consecutive patients who received HTx and were followed-up in our center regularly for > 1 year from June 2006 to May 2018. We investigated the incidence of and risk factors for de novo malignancy. The cumulative incidence of each malignancy type during the follow-up period was one (0.98%) for skin cancer, four (3.92%) for nonskin solid organ cancer, and six (5.88%) for posttransplant lymphoproliferative disorder (PTLD). The percentage of patients with more than one infectious event ≤ 1 year after HTx was higher in the malignancy group than in the non-malignancy group. Furthermore, Kaplan-Meier analysis revealed that the incidence rate of infectious events was higher in patients with malignancies than in those without (log-rank P < 0.001). After dividing malignancies into a PTLD group and a solid organ malignancy group, we found that negative Epstein-Barr virus serostatus, cytomegalovirus-positive antigenemia, and the occurrence of any viral or gastrointestinal infectious event at ≤ 1 year were more frequent in patients with PTLD than in patients without it. The survival rate was significantly lower for patients with solid organ malignancy than for patients without malignancy. In conclusion, there was a correlation between infectious events and de novo malignancy, particularly in patients with PTLD. We should confirm this finding by conducting a larger cohort study.

Concise Syntheses of Violaceoids A and C.

The concise syntheses of two alkylated hydroquinone natural products, violaceoids A and C, were accomplished by a protecting-group-free method employing the commercially available 2,5-dihydroxybenzaldehyde as the starting material. The key strategy of the syntheses is the utilization of alkenylboronic acid as both the coupling and temporary protective reagents to efficiently introduce the requisite alkenyl side chain of violaceoid A. Moreover, the synthesis of violaceoid C is reported here for the first time.

A novel approach to oxazole-containing diterpenoid synthesis from plant roots: salviamines E and F.

In this study, salviamines E and F, which are structurally unique abietane-type diterpene alkaloids containing an oxazole ring, were efficiently synthesized from a known molecule, 5,7,8-trimethoxy-1-naphthol. The synthetic sequence involves the following crucial steps: (i) the assembly of a carbon skeleton by coupling a six-carbon homoprenyl unit with a naphthalene moiety (Kumada-Tamao-Corriu coupling); (ii) the construction of a tricyclic phenanthrene ring by acid-induced cyclization of a naphthalene derivative with a homoprenyl side chain; (iii) the formation of an oxazole ring by nucleophilic ring closure of a 2-aminophenylene-1,4-diyl-diformate or -diacetate moiety and (iv) Friedel-Crafts acetylation at the C13 position of the tetracyclic intermediates to obtain the two target molecules, salviamines E and F. To the best of our knowledge, salviamine synthesis is reported here for the first time.

A novel approach to sesquiterpenoid benzoxazole synthesis from marine sponges: nakijinols A, B and E-G.

Nakijinols A, B and analogues E through G, which are structurally unique and biologically significant sesquiterpenoid benzoxazoles, can be efficiently obtained in a highly unified manner from the sesquiterpenoid quinone, smenospongine. The starting material is accessible from the (+)-5-methyl Wieland-Miescher ketone. The synthetic method features strategic construction of the requisite dihydroxylated benzoxazole substructure via the ring closure of the N-(2-hydroxyphenyl)-formamide or -acetamide moiety. The synthesis of nakijinols is reported here for the first time. The absolute configurations of nakijinols A and E were also established.

Antitumor activity and pharmacologic characterization of the depsipeptide analog as a novel histone deacetylase/ phosphatidylinositol 3-kinase dual inhibitor.

Histone deacetylase (HDAC)/phosphatidylinositol 3-kinase (PI3K) dual inhibition is a promising strategy for the treatment of intractable cancers because of the advantages of overcoming potential resistance and showing synergistic effects. Therefore, development of an HDAC/PI3K dual inhibitor is reasonably attractive. Romidepsin (FK228, depsipeptide) is a potent HDAC inhibitor. We previously reported that depsipeptide and its analogs have an additional activity as PI3K inhibitors and are defined as HDAC/PI3K dual inhibitors. Subsequently, we identified FK-A11 as the most potent analog and reported its biochemical, biological, and structural properties as an HDAC/PI3K dual inhibitor. In this study, we reveal the in vitro and in vivo efficacy of FK-A11 in HT1080 fibrosarcoma and PC3 prostate cancer cell xenograft mouse models. FK-A11 showed in vivo antitumor activity by both i.v. and i.p. administration in a dose-dependent manner. In both xenograft models, FK-A11 showed superior antitumor effects compared to other depsipeptide analogs in accordance with in vitro anti-cell proliferation effects and the potency of HDAC/PI3K dual inhibition. In addition, we showed evidence of HDAC/PI3K dual inhibition accompanying antitumor efficacy in xenograft tumor tissues by immunohistochemistry. We also detailed pharmacokinetic characterization of FK-A11 in mice. These findings will be essential for guiding further preclinical and clinical studies.

Total Synthesis of Thailandepsin B, a Potent HDAC Inhibitor Isolated from a Microorganism.

Thailandepsin B, a bicyclic depsipeptide histone deacetylase inhibitor, was efficiently synthesized in 51% overall yield in eight steps, starting from commercially available D-norleucine methyl ester and known (S,E)-3-(4-methoxybenzyloxy)-7-(tritylthio)hept-4-enoic acid. The method features a convergent approach in which the corresponding seco-acid, a key precursor in macrolactonization, is directly assembled through the condensation of a D-allo-isoleucine-D-cysteine-containing segment with a D-norleucine-containing segment.

Biochemical, biological and structural properties of romidepsin (FK228) and its analogs as novel HDAC/PI3K dual inhibitors.

Romidepsin (FK228, depsipeptide) is a potent histone deacetylase (HDAC) inhibitor that has FDA approval for the treatment of cutaneous and peripheral T-cell lymphomas. We have previously reported that FK228 and its analogs have an additional activity as phosphatidylinositol 3-kinase (PI3K) inhibitors, and are defined as HDAC/PI3K dual inhibitors. Because a combination of an HDAC inhibitor and a PI3K inhibitor induces apoptosis in human cancer cells in a synergistic manner, development of an HDAC/PI3K dual inhibitor will provide an attractive novel drug for cancer therapy. Using structure-based optimization of the analogs, FK-A11 was identified as the most potent analog. FK-A11 inhibited phosphorylation of AKT and accelerated histone acetylation at lower concentrations, resulting in stronger cytotoxic effects than FK228 and the other analogs in human cancer cells. In this study, we have characterized the biochemical, biological and structural properties of FK228 analogs as PI3K inhibitors. First, FK-A11 is an ATP competitive PI3K inhibitor. Second, FK-A11 is a pan-p110 isoform inhibitor. Third, FK-A11 selectively inhibits PI3K among 22 common cellular kinases. Fourth, conformational changes of FK228 analogs by reduction of an internal disulfide bond have no effect on PI3K inhibitory activity, unlike HDAC inhibitory activity. Finally, molecular modeling of PI3K-FK228 analogs and analyses of the binding affinities identified the structure that defines potency for PI3K inhibitory activity. These results prove our concept that a series of FK228 analogs are HDAC/PI3K dual inhibitors. These findings should help in the development of FK228 analogs as novel HDAC/PI3K dual inhibitors.

Enantioselective total synthesis of dysidavarone A, a novel sesquiterpenoid quinone from the marine sponge Dysidea avara.

Dysidavarone A, a structurally unprecedented sesquiterpenoid quinone, was synthesized in 30 % overall yield in a longest liner sequence of 13 steps from commercially available o-vanillin. A highly strained and bridged eight-membered carbocyclic core was established by the C7-C21 carbon bond formation through a copper enolate mediated Michael addition to the internal quinone ring.

Evaluation of the antiplasmodial efficacy of synthetic 2,5-diphenyloxazole analogs of compounds naturally derived from Oxytropis lanata.

The persistent prevalence and dissemination of drug-resistant malaria parasites continue to challenge the progress of malaria eradication efforts. As a result, there is an urgent need to search for and develop innovative therapies. In this study, we screened synthetic 2,5-diphenyloxazole analogs from Oxytropis lanata. Among 48 compounds, 14 potently inhibited the proliferation of P. falciparum strains 3D7 (chloroquine-sensitive) and K1 (multidrug-resistant) in vitro, exhibited IC50 values from 3.38 to 12.65 µM and 1.27-6.19 µM, respectively, and were toxic to human foreskin fibroblasts at 39.53-336.35 µM. Notably, Compounds 31 (2-(2',3'-dimethoxyphenyl)-5-(2″-hydroxyphenyl)oxazole) and 32 (2-(2',3'-dimethoxyphenyl)-5-(2″-benzyloxyphenyl)oxazole) exhibited the highest selectivity indices (SIs) against both P. falciparum strains (3D7/K1), with values > 40.20/>126.58 and > 41.27/> 59.06, respectively. In the IC50 speed and stage-specific assays, Compounds 31 and 32 showed slow action, along with distinct effects on the ring and trophozoite stages. Microscopy observations further revealed that both compounds impact the development and delay the progression of the trophozoite and schizont stages in P. falciparum 3D7, especially at concentrations 100 times their IC50 values. In a 72-h in vitro exposure experiment at their respective IC80 in P. falciparum 3D7, significant alterations in parasitemia levels were observed compared to the untreated group. In Compound 31-treated cultures, parasites shrank and were unable to reinvade red blood cells (RBCs) during an extended 144-h incubation period, even after compound removal from the culture. In vivo assessments were conducted on P. yoelii 17XNL-infected mice treated with Compounds 31 and 32 at 20 mg/kg administered once daily for ten days. The treated groups showed statistically significant lower peaks of parasitemia (Compound 31-treated: trial 1 12.7%, trial 2 15.8%; Compound 32-treated: trial 1 12.7%, trial 2 14.0%) compared to the untreated group (trial 1 21.7%, trial 2 28.3%). These results emphasize the potential of further developing 2,5-diphenyloxazoles as promising antimalarial agents.

The potential of the transformer-based survival analysis model, SurvTrace, for predicting recurrent cardiovascular events and stratifying high-risk patients with ischemic heart disease.

INTRODUCTION: Ischemic heart disease is a leading cause of death worldwide, and its importance is increasing with the aging population. The aim of this study was to evaluate the accuracy of SurvTrace, a survival analysis model using the Transformer-a state-of-the-art deep learning method-for predicting recurrent cardiovascular events and stratifying high-risk patients. The model's performance was compared to that of a conventional scoring system utilizing real-world data from cardiovascular patients. METHODS: This study consecutively enrolled patients who underwent percutaneous coronary intervention (PCI) at the Department of Cardiovascular Medicine, University of Tokyo Hospital, between 2005 and 2019. Each patient's initial PCI at our hospital was designated as the index procedure, and a composite of major adverse cardiovascular events (MACE) was monitored for up to two years post-index event. Data regarding patient background, clinical presentation, medical history, medications, and perioperative complications were collected to predict MACE. The performance of two models-a conventional scoring system proposed by Wilson et al. and the Transformer-based model SurvTrace-was evaluated using Harrell's c-index, Kaplan-Meier curves, and log-rank tests. RESULTS: A total of 3938 cases were included in the study, with 394 used as the test dataset and the remaining 3544 used for model training. SurvTrace exhibited a mean c-index of 0.72 (95% confidence intervals (CI): 0.69-0.76), which indicated higher prognostic accuracy compared with the conventional scoring system's 0.64 (95% CI: 0.64-0.64). Moreover, SurvTrace demonstrated superior risk stratification ability, effectively distinguishing between the high-risk group and other risk categories in terms of event occurrence. In contrast, the conventional system only showed a significant difference between the low-risk and high-risk groups. CONCLUSION: This study based on real-world cardiovascular patient data underscores the potential of the Transformer-based survival analysis model, SurvTrace, for predicting recurrent cardiovascular events and stratifying high-risk patients.

Efficacy and safety of remote cardiac rehabilitation in the recovery phase of cardiovascular diseases (RecRCR study): A multicenter, nonrandomized, and interventional trial in Japan.

Backgrounds: Remote cardiac rehabilitation has proven useful in patients with cardiovascular disease; however, the methodology had not been fully validated. This study aimed to investigate the efficacy and safety of remote cardiac rehabilitation (RCR) with real-time monitoring and an ergometer using a bidirectional communication tool during the recovery phase of cardiovascular diseases. Methods: This multicenter, nonrandomized, interventional study was conducted at 29 institutions across Japan and enrolled patients with cardiovascular diseases who met indications for cardiac rehabilitation (CR) after receiving in-hospital treatment. The RCR group exercised at home using an ergometer and was monitored in real-time using interactive video and monitoring tools for 2-3 months. Educational instructions were provided concurrently through e-learning approaches. The safety of the RCR protocol and the improvement in peak oxygen consumption (VO2) were compared with those of the historical control group that participated in center-based CR. Results: Fifty-three patients from the RCR group were compared with 103 historical controls having similar background characteristics. No patients in RCR experienced significant cardiovascular complications while engaging in exercise sessions. After 2-3 months of RCR, the peak VO2 improved significantly, and the increases in the RCR group did not exhibit any significant differences compared to those in the historical controls. During follow-up, the proportion of patients whose exercise capacity increased by 10% or more was also evaluated; this finding did not indicate a statistically significant distinction between the groups. Conclusions: RCR during the recovery phase of cardiovascular diseases proved equally efficient and safe as center-based CR.

A new assessment method for right ventricular diastolic function using right heart catheterization by pressure-volume loop.

Diastolic stiffness coefficient (ß) and end-diastolic elastance (Eed) are ventricular-specific diastolic parameters. However, the diastolic function of right ventricle had not been investigated sufficiently due to the lack of established evaluation method. We evaluated the validity of these parameters calculated using only data of right heart catheterization (RHC) and assessed it in patients with restrictive cardiomyopathy (RCM) and cardiac amyloidosis. We retrospectively analyzed 46 patients with heart failure who underwent RHC within 10 days of cardiac magnetic resonance (CMR). Right ventricular end-diastolic volume and end-systolic volume were calculated using only RHC data, which were found to be finely correlated with those obtained from CMR. ß and Eed calculated by this method were also significantly correlated with those derived from conventional method using CMR. By this method, ß and Eed were significantly higher in RCM with amyloidosis group than dilated cardiomyopathy group. In addition, the ß and Eed calculated by our method were finely correlated with E/A ratio on echocardiography. We established an easy method to estimate ß and Eed of right ventricle from only RHC. The method finely demonstrated right ventricular diastolic dysfunction in patients with RCM and amyloidosis.

[Synthetic Study on Bicyclic Depsipeptides Containing an Intramolecular Disulfide Bond].

Bicyclic depsipeptide natural products containing an intramolecular disulfide bond are potent histone deacetylase (HDAC) inhibitors. Among them, FK228 (romidepsin) is approved for treating cutaneous T-cell lymphoma and peripheral T-cell lymphoma. This study focused on developing a new synthesis method for producing this class of natural products for use as HDAC inhibitors with high efficacy and low toxicity. In this paper, the total syntheses of FK228 as well as spiruchostatins A and B are described. The synthesis routes include a convergent way to assemble seco-acids via the amide condensation of amine segments with carboxylic acid segments. The syntheses of C4- and C7-modified FK228 analogs (FK-A1 to FK-A8) are also described. The evaluation of HDAC and cell growth inhibitory activities of the synthesized analogs revealed novel aspects of their structure-activity relationship. Potent and highly isoform-selective HDAC1 inhibitors were identified. Furthermore, the analogs showed phosphatidylinositol 3-kinase (PI3K) inhibitory activity. Structural optimization of the analogs as HDAC/PI3K dual inhibitors led to the identification of FK-A11 as the most potent analog.

Total synthesis and antimicrobial evaluation of (+)-hygrophorone B12 and its analogues.

This paper describes the synthesis and evaluation of lead compounds with a new chemical skeleton that is not found in conventional antimicrobial agents. The biologically attractive cyclopentenoid (+)-hygrophorone B12, isolated from the fruiting bodies of Hygrophorus abieticola, and its analogues were synthesized in a longer linear sequence of twelve steps, starting from a cyclopentenone derivative. This synthesis involved the following crucial steps: (i) oximation of a ketone to stabilize the requisite aldehyde to install a side chain and (ii) coupling of an aldehyde with a side chain to assemble the desired hygrophorone. Then, the antimicrobial activity of these hygrophorones towards clinically relevant bacterial pathogens was evaluated. The results showed that hygrophorone B12 and its analogues are especially effective in preventing the proliferation of gram-positive bacteria. In addition, it was found that some structural features such as the presence of the enone moiety as well as the carbon-carbon triple bond on the hydrocarbon chain were pivotal to increase the antimicrobial activity of hygrophorone B. This study is expected to support the development of novel antimicrobial agents by flexibly synthesizing hygrophorone B analogues with a carbon five-membered ring skeleton from the common intermediate.

Determining the factors for interhospital transfer in advanced heart failure cases.

Background: There are some patients with advanced heart failure (HF), for whom implantable left ventricular assist device (LVAD) or heart transplantation (HTx) should be considered. Some of them need to be transferred between hospitals. There are few reports on the interhospital transfer of patients with advanced HF and their subsequent clinical course.In this study, we investigated the characteristics and clinical course of patients transferred to a LVAD/HTx center, focusing on the distance between hospitals. Methods: We retrospectively examined 141 patients who were transferred to our hospital, considering the indications of LVAD implantation or HTx. We divided the patients into two groups: those referred <33 km (short-distance) and those referred more than 33 km (long-distance). The primary outcome was the composite outcome of increased catecholamine dose, mechanical support, or renal dysfunction within 1 week of transfer. Results: Continuous catecholamine infusion was significantly more common in patients in the long-distance group, whereas extracorporeal membrane oxygenation (ECMO) placement was significantly more common in short-distance group.Patients transferred via long distance had significantly higher rates of increased catecholamine doses, mechanical support including intra-aortic balloon pumping (IABP) and ECMO, and renal dysfunction within 1 week of transfer than patients transferred via short distance. Multivariate analysis showed that low body mass index (BMI) and long distance were independent predictive factors for the primary outcome. Conclusions: When patients with advanced HF are transferred from far distant hospitals or with low BMI, it may be necessary to devise various measures for interhospital transport.

Residual Pulmonary Vascular Resistance Increase Under Left Ventricular Assist Device Support Predicts Long-Term Cardiac Function After Heart Transplantation.

Aims: We compared hemodynamics and clinical events after heart transplantation (HTx) in patients stratified by the severity of residual pulmonary vascular resistance (PVR) after left ventricular assist device (LVAD) implantation for bridge to transplantation. Methods: We retrospectively analyzed patients who had undergone HTx at the University of Tokyo Hospital. We defined the high PVR group as patients with PVR of >3 Wood Units (WU) as measured by right heart catheterization performed 1 month after LVAD implantation. Results: We included 85 consecutive HTx recipients, 20 of whom were classified in the high PVR group and 65 in the low PVR group. The difference in PVR between the two groups became apparent at 2 years after HTx (the high PVR group: 1.77 ± 0.41 WU, the low PVR group: 1.24 ± 0.59 WU, p = 0.0009). The differences in mean pulmonary artery pressure (mPAP), mean right arterial pressure (mRAP), and mean pulmonary capillary wedge pressure (mPCWP) tended to increase from the first year after HTx, and were all significantly higher in the high PVR group at 3 years after HTx (mPAP: 22.7 ± 9.0 mm Hg vs. 15.4 ± 4.3 mm Hg, p = 0.0009, mRAP: 7.2 ± 3.6 mm Hg vs. 4.1 ± 2.1 mm Hg, p = 0.0042, and mPCWP: 13.4 ± 4.5 mm Hg, 8.8 ± 3.3 mm Hg, p = 0.0040). In addition, pulmonary artery pulsatility index was significantly lower in the high PVR group than in the low PVR group at 3 years after HTx (2.51 ± 1.00 vs. 5.21 ± 3.23, p = 0.0033). The composite event including hospitalization for heart failure, diuretic use, and elevated intracardiac pressure (mRAP ≥ 12 mm Hg or mPCWP ≥ 18 mm Hg) between the two groups was significantly more common in the high PVR group. Residual high PVR was still an important predictor (hazard ratio 6.5, 95% confidence interval 2.0-21.6, and p = 0.0023) after multivariate Cox regression analysis. Conclusion: Our study demonstrates that patients with residual high PVR under LVAD implantation showed the increase of right and left atrial pressure in the chronic phase after HTx.

Incorporation and remodeling of phosphatidylethanolamine containing short acyl residues in yeast.

Phosphatidylethanolamine (PE) is one of the essential phospholipids in the yeast Saccharomyces cerevisiae. We have previously shown that a yeast strain, the endogenous PE synthesis of which was controllable, grew in the presence of PE containing decanoyl residues (diC10PE) when PE synthesis was repressed. In this study, we investigated the fate of diC10PE, its uptake and remodeling in yeast. Deletion of the genes encoding Lem3p/Ros3p or P-type ATPases, Dnf1p and Dnf2p, impaired the growth of the mutants in the medium containing diC10PE, suggesting the involvement of these proteins in the uptake of diC10PE. Analysis of the metabolism of deuterium-labeled diC10PE by electrospray ionization tandem mass spectrometry revealed that it was rapidly converted to deuterium-labeled PEs containing C16 or C18 acyl residues. The probable intermediate PEs that contained decanoic acid and C16 or C18 fatty acids as acyl residues were also detected. In addition, a substantial amount of decanoic acid was released into the culture medium during growth in the presence of diC10PE. These results imply that diC10PE was remodeled to PEs with longer acyl residues and used as membrane components. Defects in the remodeling of diC10PE in the deletion mutants of ALE1 and SLC1, products of which were capable of acyl-transfer to the sn-2 position of lyso-phospholipids, suggested their involvement in the introduction of acyl residues to the sn-2 position of lyso-phosphatidylethanolamine in the remodeling reaction of diC10PE. Our results also suggest the presence of a mechanism to maintain the physiological length of PE acyl residues in yeast.

Is branched-chain amino acid nutritional supplementation beneficial or detrimental in heart failure?

Sarcopenia or cachexia is often complicated in heart failure. Nutritional support, particularly branched-chain amino acid (BCAA) supplementation, is a candidate treatment for improving sarcopenia or cachexia in elderly patients. However, the efficacy of BCAA supplementation in patients with heart failure has not been established, and the issue is comparatively more complex. Indeed, there are conflicting reports on the efficacy of BCAA supplementation. The evidence for including BCAA supplementation in treating patients with heart failure was reviewed, and the complexity of the issue was discussed.