Abstract Background Some, but not all, patients with heart failure (HF) develop pulmonary vascular disease (PVD), which contributes to poor prognosis. Mechanisms leading to PVD in HF are poorly understood. Unbiased analysis of transpulmonary gradients may identify not only markers but also mediators of PVD by identifying proteins that may be consumed or elaborated across the lungs. Purpose Examine hemodynamics and transpulmonary proteome gradients in HFrEF and controls. Methods 21 non-HF controls and 160 patients with advanced HFrEF underwent pulmonary artery (PA) catheterization with blood sampling from the PA catheter in the wedged position (02sat > 90%, indicating pulmonary venous blood) and the un-wedged position to obtain transpulmonary proteome gradients. Samples from controls and HF from the highest quartile (Q4, n=40) and lowest quartile (Q1, n=40) of pulmonary vascular resistance (PVR) were analyzed using proteomic PEA assay of 275 proteins (Olink Target 96, panels CVII, CVIII, Inflammation). Pulmonary artery concentrations ("markers") or transpulmonary fold-change gradients (i.e. putative "mediators") of normalized protein expression (NPX) were plotted against significance; Benjamini–Hochberg FDR<0.05 considered as significant. Results Patients displayed typical characteristics of HFrEF (age 56±8y, NYHA 3.0 ±0.6, 87% males, LVEF 24±9.6%), Controls had similar anthropometrics, gender and age. Comparing all HF to Con, 38 markers of HF were identified (NPX fold-change>2), including 33 up (top 5: NTproBNP, BNP, GDF15, FGF23, IL8) and 5 down. HF patients in Q1 had median PVR 1.5 (IQR: 0.3-1.7) WU and those in Q4 had PVR 5.4 (4.3-6.6) WU. Comparison of Q1 and Q4 identified 3 protein markers of high PVR in PA blood from HF: chemokine CCL3, TNFRSF13B and surfactant protein-D (PSP-D). Examination of protein gradients from HF lungs (Figure) showed significant uptake of 14 protein mediators, most of which were associated with inflammatory responses (top 5: OSM, MMP9, CCL19, BNP, TR), and release of 8 mediators (top 4: IL-6, IL33, CCL4, CXCL10). In contrast, protein gradients were negligible in controls. Patients in Q4 PVR group were characterized by the highest pulmonary uptake of OSM (Oncostatin-M), lymphatic chemokine CCL19, BNP, MMP9, and had more significant transpulmonary release of IL6 and IL33. Across all patients, OSM lung uptake was the strongest correlate of transpulmonary pressure gradient (r=-0.3, p<0.001). Conclusions Lungs of patients with HF, and particularly those with high PVR, display abnormal uptake and release of proinflammatory CC and CXC chemokines and cytokines from IL1 and IL6 family, along with increased pulmonary uptake of IL6-type cytokine Oncostatin-M, a known mediator of lung inflammation and fibrosis, that acts via gp130/JAK/STAT, suggesting a novel role in PVD due to HF.Transpulmonary proteome in HF patients
Metformin Improves Glycemic Control and Postprandial Metabolism and Enhances Postprandial Glucagon-Like Peptide 1 Secretion in Patients With Type 2 Diabetes and Heart Failure: A Randomized, Double-Blind, Placebo-Controlled Trial
This randomized trial tested the effect of metformin on glycemic control and cardiac function in patients with heart failure (HF) and type 2 diabetes while evaluating intestinal effects on selected gut microbiome products reflected by trimethylamine-N-oxide (TMAO) and gut-derived incretins. Metformin treatment improved glycemic control and postprandial metabolism and enhanced postprandial glucagon-like peptide 1 (GLP-1) secretion but did not influence cardiac function or the TMAO levels. Metabolic effects of metformin in HF may be mediated by an improvement in intestinal endocrine function and enhanced secretion of the gut-derived incretin GLP-1.
Circulating Beta-Hydroxybutyrate Levels in Advanced Heart Failure with Reduced Ejection Fraction: Determinants and Prognostic Impact
Abstract Aims Patients with heart failure (HF) display metabolic alterations, including heightened ketogenesis, resulting in increased beta-hydroxybutyrate (β-OHB) formation. We aimed to investigate the determinants and prognostic impact of circulating β-OHB levels in patients with advanced HF and reduced ejection fraction (HFrEF). Methods and results A total of 867 patients with advanced HFrEF (age 57 ± 11 years, 83% male, 45% diabetic, 60% New York Heart Association class III), underwent clinical and echocardiographic examination, circulating metabolite assessment, and right heart catheterization (n = 383). The median β-OHB level was 64 (interquartile range [IQR] 33–161) μmol/L (normal 0–74 μmol/L). β-OHB levels correlated with increased markers of lipolysis (free fatty acids [FFA]), higher natriuretic peptides, worse pulmonary haemodynamics, and lower humoral regulators of ketogenesis (insulin/glucagon ratio). During a median follow-up of 1126 (IQR 410–1781) days, there were 512 composite events, including 324 deaths, 81 left ventricular assist device implantations and 107 urgent cardiac transplantations. In univariable Cox regression, increased β-OHB levels (T3 vs. T1: hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.13–1.72, p = 0.002) and elevated FFA levels (T3 vs. T1: HR 1.39, 95% CI 1.09–1.79, p = 0.008) were both predictors of a worse prognosis. In multivariable Cox analysis evaluating the simultaneous associations of FFA and β-OHB levels with outcomes, only FFA levels remained significantly associated with adverse outcomes. Conclusions In patients with advanced HFrEF, increased plasma β-OHB correlate with FFA levels, worse right ventricular function, greater neurohormonal activation and other markers of HF severity. The association between plasma β-OHB and adverse outcomes is eliminated after accounting for FFA levels, suggesting that increased β-OHB is a consequence reflecting heightened lipolytic state, rather than a cause of worsening HF.
Pressure Overload is Associated with Right Ventricular Dyssynchrony in Heart Failure with Reduced Ejection Fraction
Abstract Aims The determinants and relevance of right ventricular (RV) mechanical dyssynchrony in heart failure with reduced ejection fraction (HFrEF) are poorly understood. We hypothesized that increased afterload may adversely affect the synchrony of RV contraction. Methods and results A total of 148 patients with HFrEF and 36 controls underwent echocardiography, right heart catheterization, and gated single-photon emission computed tomography to measure RV chamber volumes and mechanical dyssynchrony (phase standard deviation of systolic displacement timing). Exams were repeated after preload (N = 135) and afterload (N = 15) modulation. Patients with HFrEF showed higher RV dyssynchrony compared with controls (40.6 ± 17.5° vs. 27.8 ± 9.1°, P < 0.001). The magnitude of RV dyssynchrony in HFrEF correlated with larger RV and left ventricular (LV) volumes, lower RV ejection fraction (RVEF) and LV ejection fraction, reduced intrinsic contractility, increased heart rate, higher pulmonary artery (PA) load, and impaired RV–PA coupling (all P ≤ 0.01). Low RVEF was the strongest predictor of RV dyssynchrony. Left bundle branch block (BBB) was associated with greater RV dyssynchrony than right BBB, regardless of QRS duration. RV afterload reduction by sildenafil improved RV dyssynchrony (P = 0.004), whereas preload change with passive leg raise had modest effect. Patients in the highest tertiles of RV dyssynchrony had an increased risk of adverse clinical events compared with those in the lower tertile [T2/T3 vs. T1: hazard ratio 1.98 (95% confidence interval 1.20–3.24), P = 0.007]. Conclusions RV dyssynchrony is associated with RV remodelling, dysfunction, adverse haemodynamics, and greater risk for adverse clinical events. RV dyssynchrony is mitigated by acute RV afterload reduction and could be a potential therapeutic target to improve RV performance in HFrEF.
Abstract 180: Myocardial Triacylglycerole Accumulation Is Related To BNP And Myocardial Redox State In Advanced Systolic Heart Failure
PURPOSE: Experimental studies suggest that accumulation of triacylglyceroles (TAG) in myocardium and ensuing lipotoxicity may contribute to the progression of heart failure (HF), but relevance to human HF remains uncertain. We strived to quantify myocardial TAG in HF patients and controls and to identify their determinants. Methods: 49 myocardial samples from patients with terminal HF (52 yrs, 86% male, 45% CAD, 49% DCM, 6% other dg.) that underwent heart transplantation or LVAD implantation and 20 control samples from cadaverous organ donors without HF (42 years, 45% males) were analyzed. Myocardial TAG (determined chemically), reduced (GSH) and oxidized glutathione (GSSG) were determined. Results: Patients with HF had higher amount of myocardial TAG (8.07± 3.95 vs. 5.60±3.36 μmol/g wet tissue, p= 0.017) and lower levels of both GSH and GSSG (p< 0.05) with similar GSH/GSSG ratio. The amount of myocardial TAG was independent of age, gender, HF etiology, diabetes mellitus, BMI, mitral regurgitation grade and plasma lipids (total-, HDL-, LDL-cholesterol, TAG) but it correlated with plasmatic BNP level (p=0.049, r=0.28). In controls, a positive correlation between myocardial TAG and the myocardial redox state (GSH/GSSG ratio) was found (r=0.53, p=0.015). On the contrary, this correlation was negative (r= -0.31, p=0.02) in HF patients. Conclusion: Myocardial TAG in HF and controls have opposite relationship to redox state, indicating disparate mechanisms involved. Failing hearts display higher TAG accumulation, that is independent of comorbidities, but proportional to circulating BNP, supporting the role of natriuretic peptides in abnormal lipid homeostasis in HF.
Glucose Homeostasis, Pancreatic Endocrine Function, and Outcomes in Advanced Heart Failure
Background The mechanisms and relevance of impaired glucose homeostasis in advanced heart failure ( HF ) are poorly understood. The study goals were to examine glucose regulation, pancreatic endocrine function, and metabolic factors related to prognosis in patients with nondiabetic advanced HF. Methods and Results In total, 140 advanced HF patients without known diabetes mellitus and 21 sex‐, age‐, and body mass index–matched controls underwent body composition assessment, oral glucose tolerance testing, and measurement of glucose‐regulating hormones to model pancreatic β‐cell secretory response. Compared with controls, HF patients had similar fasting glucose and insulin levels but higher levels after oral glucose tolerance testing. Insulin secretion was not impaired, but with increasing HF severity, there was a reduction in glucose, insulin, and insulin/glucagon ratio—a signature of starvation. The insulin/C‐peptide ratio was decreased in HF , indicating enhanced insulin clearance, and this was correlated with lower cardiac output, hepatic insufficiency, right ventricular dysfunction, and body wasting. After a median of 449 days, 41% of patients experienced an adverse event (death, urgent transplant, or assist device). Increased glucagon and, paradoxically, low fasting plasma glucose displayed the strongest relations to outcome ( P =0.01). Patients in the lowest quartile of fasting plasma glucose (3.8–5.1 mmol·L −1 , 68–101 mg·dL −1 ) had 3‐times higher event risk than in the top quartile (6.0–7.9 mmol·L −1 , 108–142 mg·dL −1 ; relative risk: 3.05 [95% confidence interval, 1.46–6.77]; P =0.002). Conclusions Low fasting plasma glucose and increased glucagon are robust metabolic predictors of adverse events in advanced HF . Pancreatic insulin secretion is preserved in advanced HF , but levels decrease with increasing HF severity due to enhanced insulin clearance that is coupled with right heart failure and cardiac cachexia.
Myocardial Iron Content and Mitochondrial Function in Human Heart Failure: A Direct Tissue Analysis
Abstract Aims Iron replacement improves clinical status in iron-deficient patients with heart failure (HF), but the pathophysiology is poorly understood. Iron is essential not only for erythropoiesis, but also for cellular bioenergetics. The impact of myocardial iron deficiency (MID) on mitochondrial function, measured directly in the failing human heart, is unknown. Methods and results Left ventricular samples were obtained from 91 consecutive HF patients undergoing transplantation and 38 HF-free organ donors (controls). Total myocardial iron content, mitochondrial respiration, citric acid cycle and respiratory chain enzyme activities, respiratory chain components (complex I–V), and protein content of reactive oxygen species (ROS)-protective enzymes were measured in tissue homogenates to quantify mitochondrial function. Myocardial iron content was lower in HF compared with controls (156 ± 41 vs. 200 ± 38 µg·g−1 dry weight, P < 0.001), independently of anaemia. MID (the lowest iron tercile in HF) was associated with more extensive coronary disease and less beta-blocker usage compared with non-MID HF patients. Compared with controls, HF patients displayed reduced myocardial oxygen2 respiration and reduced activity of all examined mitochondrial enzymes (all P < 0.001). MID in HF was associated with preserved activity of respiratory chain enzymes but reduced activity of aconitase and citrate synthase (by –26% and –15%, P < 0.05) and reduced expression of catalase, glutathione peroxidase, and superoxide dismutase 2. Conclusion Myocardial iron content is decreased and mitochondrial functions are impaired in advanced HF. MID in HF is associated with diminished citric acid cycle enzyme activities and decreased ROS-protecting enzymes. MID may contribute to altered myocardial substrate use and to worsening of mitochondrial dysfunction that exists in HF.