Use of Cardiopulmonary Stress Testing for Patients With Unexplained Dyspnea Post-Coronavirus Disease.

OBJECTIVES: The authors used cardiopulmonary exercise testing (CPET) to define unexplained dyspnea in patients with post-acute sequelae of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection (PASC). We assessed participants for criteria to diagnose myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). BACKGROUND: Approximately 20% of patients who recover from coronavirus disease (COVID) remain symptomatic. This syndrome is named PASC. Its etiology is unclear. Dyspnea is a frequent symptom. METHODS: The authors performed CPET and symptom assessment for ME/CFS in 41 patients with PASC 8.9 ± 3.3 months after COVID. All patients had normal pulmonary function tests, chest X-ray, and chest computed tomography scans. Peak oxygen consumption (peak VO2), slope of minute ventilation to CO2 production (VE/VCO2 slope), and end tidal pressure of CO2 (PetCO2) were measured. Ventilatory patterns were reviewed with dysfunctional breathing defined as rapid erratic breathing. RESULTS: Eighteen men and 23 women (average age: 45 ± 13 years) were studied. Left ventricular ejection fraction was 59% ± 9%. Peak VO2 averaged 20.3 ± 7 mL/kg/min (77% ± 21% predicted VO2). VE/VCO2 slope was 30 ± 7. PetCO2 at rest was 33.5 ± 4.5 mm Hg. Twenty-four patients (58.5%) had a peak VO2 <80% predicted. All patients with peak VO2 <80% had a circulatory limitation to exercise. Fifteen of 17 patients with normal peak VO2 had ventilatory abnormalities including peak respiratory rate >55 (n = 3) or dysfunctional breathing (n = 12). For the whole cohort, 88% of patients (n = 36) had ventilatory abnormalities with dysfunctional breathing (n = 26), increased VE/VCO2 (n = 17), and/or hypocapnia PetCO2 <35 (n = 25). Nineteen patients (46%) met criteria for ME/CFS. CONCLUSIONS: Circulatory impairment, abnormal ventilatory pattern, and ME/CFS are common in patients with PASC. The dysfunctional breathing, resting hypocapnia, and ME/CFS may contribute to symptoms. CPET is a valuable tool to assess these patients.

Chronic Fatigue Syndrome and Cardiovascular Disease: JACC State-of-the-Art Review.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a medically unexplained illness characterized by severe fatigue limiting normal daily activities for at least 6 months accompanied by problems with unrefreshing sleep, exacerbation of symptoms following physical or mental efforts (postexertional malaise [PEM]), and either cognitive reports or physiological evidence of orthostatic intolerance in the form of either orthostatic tachycardia and/or hypocapnia. Although rarely considered to have cardiac dysfunction, ME/CFS patients frequently have reduced stroke volume with a significant inverse relation between cardiac output and PEM severity. Magnetic resonance imaging of ME/CFS patients compared with normal control subjects found significantly reduced stroke, end-systolic, and end-diastolic volumes together with reduced end-diastolic wall mass. Another cardiovascular abnormality is reduced nocturnal blood pressure assessed by 24-hour monitoring. Autonomic dysfunction is also frequently observed with postural orthostatic tachycardia and/or hypocapnia. Two consecutive cardiopulmonary stress tests may provide metabolic data substantiating PEM.

Challenges in heart transplantation during COVID-19: A single-center experience.

BACKGROUND: Orthotopic heart transplantation (OHT) recipients may be particularly vulnerable to coronavirus disease 2019 (COVID-19). OHT during the pandemic presents unique challenges in terms of feasibility and safety. METHODS: Chart review was performed for consecutive OHT recipients with COVID-19 and waitlisted patients who underwent OHT from March 1, 2020 to May 15, 2020. RESULTS: Of the approximately 400 OHT recipients followed at our institution, 22 acquired COVID-19. Clinical characteristics included median age 59 (range, 49-71) years, 14 (63.6%) were male, and median time from OHT to infection was 4.6 (2.5-20.6) years. Symptoms included fever (68.2%), gastrointestinal complaints (55%), and cough (46%). COVID-19 was severe or critical in 5 (23%). All patients had elevated inflammatory biomarkers. Immunosuppression was modified in 85% of patients. Most (n = 16, 86.4%) were hospitalized, 18% required intubation, and 14% required vasopressor support. Five patients (23%) expired. None of the patients requiring intubation survived. Five patients underwent OHT during the pandemic. They were all males, ranging from 30 to 59 years of age. Two were transplanted at United Network of Organ Sharing Status 1 or 2, 1 at Status 3, and 2 at Status 4. All were successfully discharged and are alive without allograft dysfunction or rejection. One contracted mild COVID-19 after the index hospitalization. CONCLUSION: OHT recipients with COVID-19 appear to have outcomes similar to the general population hospitalized with COVID-19. OHT during the pandemic is feasible when appropriate precautions are taken. Further study is needed to guide immunosuppression management in OHT recipients affected by COVID-19.

Effect of Socioeconomic Status on Patients Supported with Contemporary Left Ventricular Assist Devices.

Continuous-flow left ventricular assist devices (CF-LVADs) are increasingly used in advanced heart failure patients. Recent studies suggest that low socioeconomic status (SES) predicts worst survival after heart transplantation. Both individual-level and neighborhood-level SES (nSES) have been linked to cardiovascular health; however, the impact of SES in CF-LVAD patients remains unknown. We hypothesized that SES is a major determinant of CF-LVAD candidacy and postimplantation outcomes. A retrospective chart review was conducted on 362 patients between February 2009 and May 2016. Neighborhood-level SES was measured using the American Community Survey data and the Agency for Healthcare Research and Quality SES index score. Individual-level SES was self reported. Kaplan-Meier survival analysis and multivariable Cox proportional hazards regression determined survival statistics. Patients in the highest SES tertile were older (58 ± 13 vs. 53 ± 14; p < 0.001), less likely to be black or Hispanic (26% vs. 70%; p < 0.001), more likely to be married (87% vs. 65%; p < 0.001), more likely to have private insurance (50% vs. 39%; p < 0.001), and more likely to have employment (29% vs. 15%; p < 0.001) compared with patients in the lowest tertile. Low nSES was associated with a decreased risk of death (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.347-0.970; p = 0.038) in comparison to the high nSES. However, after adjusting for baseline clinical morbidities, the relationship was no longer present. When selecting patients for a LVAD, SES should not be thought of as an immutable risk factor. Carefully selected low-SES patients could be safely implanted with CF-LVAD with outcomes comparable to high-SES patients.

Ryanodine Receptor Calcium Leak in Circulating B-Lymphocytes as a Biomarker in Heart Failure.

BACKGROUND: Advances in congestive heart failure (CHF) management depend on biomarkers for monitoring disease progression and therapeutic response. During systole, intracellular Ca2+ is released from the sarcoplasmic reticulum into the cytoplasm through type-2 ryanodine receptor/Ca2+ release channels. In CHF, chronically elevated circulating catecholamine levels cause pathological remodeling of type-2 ryanodine receptor/Ca2+ release channels resulting in diastolic sarcoplasmic reticulum Ca2+ leak and decreased myocardial contractility. Similarly, skeletal muscle contraction requires sarcoplasmic reticulum Ca2+ release through type-1 ryanodine receptors (RyR1), and chronically elevated catecholamine levels in CHF cause RyR1-mediated sarcoplasmic reticulum Ca2+ leak, contributing to myopathy and weakness. Circulating B-lymphocytes express RyR1 and catecholamine-responsive signaling cascades, making them a potential surrogate for defects in intracellular Ca2+ handling because of leaky RyR channels in CHF. METHODS: Whole blood was collected from patients with CHF, CHF following left-ventricular assist device implant, and controls. Blood was also collected from mice with ischemic CHF, ischemic CHF+S107 (a drug that specifically reduces RyR channel Ca2+ leak), and wild-type controls. Channel macromolecular complex was assessed by immunostaining RyR1 immunoprecipitated from lymphocyte-enriched preparations. RyR1 Ca2+ leak was assessed using flow cytometry to measure Ca2+ fluorescence in B-lymphocytes in the absence and presence of RyR1 agonists that empty RyR1 Ca2+ stores within the endoplasmic reticulum. RESULTS: Circulating B-lymphocytes from humans and mice with CHF exhibited remodeled RyR1 and decreased endoplasmic reticulum Ca2+ stores, consistent with chronic intracellular Ca2+ leak. This Ca2+ leak correlated with circulating catecholamine levels. The intracellular Ca2+ leak was significantly reduced in mice treated with the Rycal S107. Patients with CHF treated with left-ventricular assist devices exhibited a heterogeneous response. CONCLUSIONS: In CHF, B-lymphocytes exhibit remodeled leaky RyR1 channels and decreased endoplasmic reticulum Ca2+ stores consistent with chronic intracellular Ca2+ leak. RyR1-mediated Ca2+ leak in B-lymphocytes assessed using flow cytometry provides a surrogate measure of intracellular Ca2+ handling and systemic sympathetic burden, presenting a novel biomarker for monitoring response to pharmacological and mechanical CHF therapy.

MicroRNA-195 Regulates Metabolism in Failing Myocardium Via Alterations in Sirtuin 3 Expression and Mitochondrial Protein Acetylation.

BACKGROUND: Heart failure leads to mitochondrial dysfunction and metabolic abnormalities of the failing myocardium coupled with an energy-depleted state and cardiac remodeling. The mitochondrial deacetylase sirtuin 3 (SIRT3) plays a pivotal role in the maintenance of mitochondrial function through regulating the mitochondrial acetylome. It is interesting to note that unique cardiac and systemic microRNAs have been shown to play an important role in cardiac remodeling by modulating key signaling elements in the myocardium. METHODS: Cellular signaling was analyzed in human cardiomyocyte-like AC16 cells, and acetylation levels in rodent models of SIRT3-/-and transgenic microRNA-195 (miR-195) overexpression were compared with wild type. Luciferase assays, Western blotting, immunoprecipitation assays, and echocardiographic analysis were performed. Enzymatic activities of pyruvate dehydrogenase (PDH) and ATP synthase were measured. RESULTS: In failing human myocardium, we observed induction of miR-195 along with decreased expression of the mitochondrial deacetylase SIRT3 that was associated with increased global protein acetylation. We further investigated the role of miR-195 in SIRT3-mediated metabolic processes and its impact on regulating enzymes involved in deacetylation. Proteomic analysis of the total acetylome showed increased overall acetylation, and specific lysine acetylation of 2 central mitochondrial metabolic enzymes, PDH and ATP synthase, as well. miR-195 downregulates SIRT3 expression through direct 3'-untranslated region targeting. Treatments with either sirtuin inhibitor nicotinamide, small interfering RNA-mediated SIRT3 knockdown or miR-195 overexpression enhanced acetylation of PDH complex and ATP synthase. This effect diminished PDH and ATP synthase activity and impaired mitochondrial respiration.SIRT3-/- and miR-195 transgenic mice consistently showed enhanced global protein acetylation, including PDH complex and ATP synthase, associated with decreased enzymatic activity. CONCLUSIONS: Altogether, these data suggest that increased levels of miR-195 in failing myocardium regulate a novel pathway that involves direct SIRT3 suppression and enzymatic inhibition via increased acetylation of PDH and ATP synthase that are essential for cardiac energy metabolism.

Serum exosomal protein profiling for the non-invasive detection of cardiac allograft rejection.

BACKGROUND: Exosomes are cell-derived circulating vesicles that play an important role in cell-cell communication. Exosomes are actively assembled and carry messenger RNAs, microRNAs and proteins. The "gold standard" for cardiac allograft surveillance is endomyocardial biopsy (EMB), an invasive technique with a distinct complication profile. The development of novel, non-invasive methods for the early diagnosis of allograft rejection is warranted. We hypothesized that the exosomal proteome is altered in acute rejection, allowing for a distinction between non-rejection and rejection episodes. METHODS: Serum samples were collected from heart transplant (HTx) recipients with no rejection, acute cellular rejection (ACR) and antibody-mediated rejection (AMR). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of serum exosome was performed using a mass spectrometer (Orbitrap Fusion Tribrid). RESULTS: Principal component analysis (PCA) revealed a clustering of 3 groups: (1) control and heart failure (HF); (2) HTx without rejection; and (3) ACR and AMR. A total of 45 proteins were identified that could distinguish between groups (q < 0.05). Comparison of serum exosomal proteins from control, HF and non-rejection HTx revealed 17 differentially expressed proteins in at least 1 group (q < 0.05). Finally, comparisons of non-rejection HTx, ACR and AMR serum exosomes revealed 15 differentially expressed proteins in at least 1 group (q < 0.05). Of these 15 proteins, 8 proteins are known to play a role in the immune response. Of note, the majority of proteins identified were associated with complement activation, adaptive immunity such as immunoglobulin components and coagulation. CONCLUSIONS: Characterizing of circulating exosomal proteome in different cardiac disease states reveals unique protein expression patterns indicative of the respective pathologies. Our data suggest that HTx and allograft rejection alter the circulating exosomal protein content. Exosomal protein analysis could be a novel approach to detect and monitor acute transplant rejection and lead to the development of predictive and prognostic biomarkers.

Regular aerobic exercise reduces endothelin-1-mediated vasoconstrictor tone in overweight and obese adults.

NEW FINDINGS: What is the central question of this study? Does aerobic exercise training reduce endothelin-1 (ET-1)-mediated vasoconstrictor tone in overweight/obese adults? And, if so, does lower ET-1 vasoconstriction underlie the exercise-related enhancement in endothelium-dependent vasodilatation in overweight/obese adults? What is the main finding and its importance? Regular aerobic exercise reduces ET-1-mediated vasoconstrictor tone in previously sedentary overweight/obese adults, independent of weight loss. Decreased ET-1 vasoconstriction is an important mechanism underlying the aerobic exercise-induced improvement in endothelium-dependent vasodilator function in overweight/obese adults. Endothelin-1 (ET-1)-mediated vasoconstrictor tone is elevated in overweight and obese adults, contributing to vasomotor dysfunction and increased cardiovascular disease risk. Although the effects of habitual aerobic exercise on endothelium-dependent vasodilatation in overweight/obese adults have been studied, little is known regarding ET-1-mediated vasoconstriction. Accordingly, the aims of the present study were to determine the following: (i) whether regular aerobic exercise training reduces ET-1-mediated vasoconstrictor tone in overweight and obese adults; and, if so, (ii) whether the reduction in ET-1-mediated vasoconstriction contributes to exercise-induced improvement in endothelium-dependent vasodilatation in this population. Forearm blood flow (FBF) in response to intra-arterial infusion of selective ETA receptor blockade (BQ-123, 100 nmol min-1 for 60 min), acetylcholine [4.0, 8.0 and 16.0 µg (100 ml tissue)-1  min-1 ] in the absence and presence of ETA receptor blockade and sodium nitroprusside [1.0, 2.0 and 4.0 µg (100 ml tissue)-1  min-1 ] were determined before and after a 3 month aerobic exercise training intervention in 25 (16 men and nine women) overweight/obese (body mass index 30.1 ± 0.5 kg m-2 ) adults. The vasodilator response to BQ-123 was significantly lower (∼25%) and the FBF responses to acetylcholine were ∼35% higher after exercise training. Before the exercise intervention, the co-infusion of acetylcholine plus BQ-123 resulted in a greater vasodilator response than acetylcholine alone; however, after the exercise intervention the FBF response to acetylcholine was not significantly increased by ETA receptor blockade. These results demonstrate that regular aerobic exercise reduces ET-1-mediated vasoconstrictor tone in previously sedentary overweight and obese adults. Moreover, decreased ET-1-mediated vasoconstriction is an important mechanism underlying the aerobic exercise-induced improvement in endothelium-dependent vasodilator function in overweight/obese adults.

Increased de novo ceramide synthesis and accumulation in failing myocardium.

Abnormal lipid metabolism may contribute to myocardial injury and remodeling. To determine whether accumulation of very long-chain ceramides occurs in human failing myocardium, we analyzed myocardial tissue and serum from patients with severe heart failure (HF) undergoing placement of left ventricular assist devices and controls. Lipidomic analysis revealed increased total and very long-chain ceramides in myocardium and serum of patients with advanced HF. After unloading, these changes showed partial reversibility. Following myocardial infarction (MI), serine palmitoyl transferase (SPT), the rate-limiting enzyme of the de novo pathway of ceramide synthesis, and ceramides were found increased. Blockade of SPT by the specific inhibitor myriocin reduced ceramide accumulation in ischemic cardiomyopathy and decreased C16, C24:1, and C24 ceramides. SPT inhibition also reduced ventricular remodeling, fibrosis, and macrophage content following MI. Further, genetic deletion of the SPTLC2 gene preserved cardiac function following MI. Finally, in vitro studies revealed that changes in ceramide synthesis are linked to hypoxia and inflammation. In conclusion, cardiac ceramides accumulate in the failing myocardium, and increased levels are detectable in circulation. Inhibition of de novo ceramide synthesis reduces cardiac remodeling. Thus, increased de novo ceramide synthesis contributes to progressive pathologic cardiac remodeling and dysfunction.

Periodontitis and bone metabolism in patients with advanced heart failure and after heart transplantation.

AIMS: Heart failure (HF) is a multi-organ, pro-inflammatory syndrome that impairs bone metabolism. Pro-inflammatory cytokines and bone catabolism enhance periodontal disease, a local inflammatory, bacteria-induced disease that causes bone loss and periodontal soft tissue destruction. METHODS AND RESULTS: Medical and dental examinations were performed on patients with HF (n = 39), following heart transplantation (post-HTx, n = 38) and controls (n = 32). Blood, saliva, and gingival crevicular fluid were analysed for bone metabolism and inflammation markers. HF average New York Heart Association classification was III. Average time since HTx was 1414 days. Pro-inflammatory tumour necrosis factor-alpha was higher in HF and HTx as compared with controls (P < 0.05). Both HF and HTx participants had higher levels of bone resorption marker C-terminal telopeptide and parathyroid hormone with subjects in the HF group having the highest serum levels of all groups (P ≤ 0.05). In contrast, 25-hydroxyvitamin D was lowest in HF. HF patients had greater clinical attachment loss, cumulative pockets depth (greater than 3 mm) and probing depth (P < 0.05) as compared with controls. Cumulative pockets depth correlated significantly with measures of the inflammatory burden, ß-glucuronidase in saliva (r = 0.4863, P < 0.01), interleukin-1b in saliva (r = 0.5149, P < 0.01), and gingival crevicular fluid (r = 0.6056, P < 0.001) in HF. However, adjustment of periodontal results for measures of oral hygiene (plaque, bleeding on probing), systemic 25-hydroxyvitamin D, and race attenuated significant differences between groups. CONCLUSIONS: Patients with HF exhibit more severe periodontal disease associated with increased bone turnover markers when compared with control patients. However, local and systemic factors may account for this association and should be evaluated in future studies.

Exercise capacity, physical activity, and morbidity.

Muscle weakness and atrophy are key characteristics of the aging adult but can also be found in chronically ill patients with heart failure, cancer, renal failure, and chronic infectious diseases all associated with an accelerated level of muscle dysfunction. Reduced physical activity levels and exercise intolerance increase muscle loss and decrease quality of life in both the aging and heart failure populations. The purpose of this review is to provide an overview of the effects of aging and heart failure on skeletal muscle function and how exercise training can improve long-term outcomes associated with skeletal muscle dysfunction.

Transthyretin Cardiac Amyloidosis in Older Americans.

Wild-type transthyretin cardiac amyloidosis (ATTRwt), formerly called senile cardiac amyloidosis (SCA), is almost exclusively a disorder of older adults. As the population ages, the diagnosis of ATTRwt will increase, making it the most common form of cardiac amyloidosis. An important precondition to reduce underdiagnosis and misdiagnosis is to maintain a high index of suspicion for cardiac amyloidosis. Several clues can be gleaned from the clinical history, physical exam, electrocardiography, and noninvasive imaging techniques. Nuclear scintigraphy agents using 99mTc-phosphate derivatives combined with assessment for monoclonal proteins are eliminating the need for tissue confirmation in ATTR. Morbidity and mortality from ATTRwt cardiac amyloid is high and the emergence of numerous therapies based on a biologic understanding of the pathophysiology of this condition, including drugs to inhibit the synthesis of TTR, stabilize TTR, and degrade or extract amyloid, provides new hope for those afflicted. This review briefly covers the epidemiology, pathophysiology, and clinical manifestations, as well as diagnostic strategies and treatment, of ATTR in older adults.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure.

UNLABELLED: Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 µg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this ß-blocker on endothelial vasodilation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

Vascular inflammation and abnormal aortic histomorphometry in patients after pulsatile- and continuous-flow left ventricular assist device placement.

BACKGROUND: Left ventricular assist devices are increasingly being used in patients with advanced heart failure as both destination therapy and bridge to transplant. We aimed to identify histomorphometric, structural and inflammatory changes after pulsatile- and continuous-flow left ventricular assist device placement. METHODS: Clinical and echocardiographic data were collected from medical records. Aortic wall diameter, cellularity and inflammation were assessed by immunohistochemistry on aortic tissue collected at left ventricular assist device placement and at explantation during heart transplantation. Expression of adhesion molecules was quantified by Western blot. RESULTS: Decellularization of the aortic tunica media was observed in patients receiving continuous-flow support. Both device types showed an increased inflammatory response after left ventricular assist device placement with variable T-cell and macrophage accumulations and increased expression of vascular E-selectin, ICAM and VCAM in the aortic wall. CONCLUSIONS: Left ventricular assist device implantation is associated with distinct vascular derangements with development of vascular inflammation. These changes are pronounced in patients on continuous-flow left ventricular assist and associated with aortic media decellularization. The present findings help to explain the progressive aortic root dilation and vascular dysfunction in patients after continuous-flow device placement.

Analysis of Skeletal Muscle Torque Capacity and Circulating Ceramides in Patients with Advanced Heart Failure.

BACKGROUND: Heart failure (HF)-related exercise intolerance is thought to be perpetuated by peripheral skeletal muscle functional, structural, and metabolic abnormalities. We analyzed specific dynamics of muscle contraction in patients with HF compared with healthy, sedentary controls. METHODS: Isometric and isokinetic muscle parameters were measured in the dominant upper and lower limbs of 45 HF patients and 15 healthy age-matched controls. Measurements included peak torque normalized to body weight, work normalized to body weight, power, time to peak torque, and acceleration and deceleration to maximum strength times. Body morphometry (dual energy X-ray absorptiometry scan) and circulating fatty acids and ceramides (lipodomics) were analyzed in a subset of subjects (18 HF and 9 controls). RESULTS: Extension and flexion time-to-peak torque was longer in the lower limbs of HF patients. Furthermore, acceleration and deceleration times in the lower limbs were also prolonged in HF subjects. HF subjects had increased adiposity and decreased lean muscle mass compared with controls. Decreased circulating unsaturated fatty acids and increased ceramides were found in subjects with HF. CONCLUSIONS: Delayed torque development suggests skeletal muscle impairments that may reflect abnormal neuromuscular functional coupling. These impairments may be further compounded by increased adiposity and inflammation associated with increased ceramides.

Supplementation of l-Alanyl-l-Glutamine and Fish Oil Improves Body Composition and Quality of Life in Patients With Chronic Heart Failure.

BACKGROUND: Skeletal muscle dysfunction and exercise intolerance are clinical hallmarks of patients with heart failure. These have been linked to a progressive catabolic state, skeletal muscle inflammation, and impaired oxidative metabolism. Previous studies suggest beneficial effects of ω-3 polyunsaturated fatty acids and glutamine on exercise performance and muscle protein balance. METHODS AND RESULTS: In a randomized double-blind, placebo-controlled trial, 31 patients with heart failure were randomized to either l-alanyl-l-glutamine (8 g/d) and polyunsaturated fatty acid (6.5 g/d) or placebo (safflower oil and milk powder) for 3 months. Cardiopulmonary exercise testing, dual-energy x-ray absorptiometry, 6-minute walk test, hand grip strength, functional muscle testing, echocardiography, and quality of life and lateral quadriceps muscle biopsy were performed at baseline and at follow-up. Oxidative capacity and metabolic gene expression were analyzed on muscle biopsies. No differences in muscle function, echocardiography, 6-minute walk test, or hand grip strength and a nonsignificant increase in peak VO2 in the treatment group were found. Lean body mass increased and quality of life improved in the active treatment group. Molecular analysis revealed no differences in muscle fiber composition, fiber cross-sectional area, gene expression of metabolic marker genes (PGC1α, CPT1, PDK4, and GLUT4), and skeletal muscle oxidative capacity. CONCLUSIONS: The combined supplementation of l-alanyl-l-glutamine and polyunsaturated fatty acid did not improve exercise performance or muscle function but increased lean body mass and quality of life in patients with chronic stable heart failure. These findings suggest potentially beneficial effects of high-dose nutritional polyunsaturated fatty acids and amino acid supplementations in patients with chronic stable heart failure. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01534663.