Myocardial Lipid Metabolism in the End-Stage Failing: Heart: Evidence for an Energy-Starved State

Abstracts S89 2( 23) Virtual Implantation of the 50cc Total Artificial Heart R.A. Moore , P.C. Madueme, A. Lorts, D.L. Morales, M.D. Taylor.   The Heart Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. Purpose: Our group previously described successful use of virtual implantation of the 70cc Total Artificial Heart (TAH) to predict safe placement in small-size patients not meeting standard fit criteria. With the new 50cc TAH, there is an opportunity for broader use of the TAH device in pediatric patients with biventricular heart failure. The proposed fit criteria for the 50cc TAH (BSA 1.2-1.6 m2) has not been tested in actual patients. The study objective was to determine the efficacy of virtual implantation of the 50cc and 70cc TAH in a cohort of pediatric heart failure patients and compare virtual fit results with proposed fit criteria. Methods: A chest CT of each patient was rendered for 3D display of the thoracic cage and intrathoracic structures. 3D-rendered representations of the 50cc and 70cc TAH devices were tested using virtual implantation of the device into the thoracic cage of each patient. The devices were assessed for intersection with the thoracic cage and intrathoracic structures. The results of the virtual implantation were compared to standard sizing of the 70cc device and the proposed criteria for each device. Results: Fifteen patients (age 3-34 years; BSA 0.67-1.99 m2), being evaluated for mechanical support as bridge-to-heart transplantation, underwent virtual implantation of the 50cc and 70cc TAH. Successful virtual fit was defined as no evidence of device intersection with the thoracic cage or important intrathoracic structures. Virtual implantation of the 50cc TAH was successful in 80% of the patient cohort compared to 33% for the larger 70cc TAH. The 50cc TAH proposed criteria matched well with the virtual implantation results for this cohort with 85% concordance. The virtual implantation demonstrated device fit in 2 patients outside the proposed sizing criteria. Conclusion: Virtual TAH device implantation previously demonstrated successful prediction of device size compatibility. With the introduction of the new 50cc TAH device, this method can establish eligibility criteria for device placement in the pediatric population. 

2( 24) Cytokine Expression in the Myocardium Correlates With Cardiac Structural and Functional Improvement Induced By Mechanical Unloading in Chronic Heart Failure N. Diakos , L. McCreath, S. Navankasattusas, A. Catino, J. Stehlik, A.G. Kfoury, C. Selzman, A. Koliopoulou, S.H. McKellar, D. Budge, K. Skedros, A. Ragnhildstveit, M. Al-Sari, U. Lam, J. Fang, D. Li, S.G. Drakos.  U.T.A.H. Cardiac Transplant Program, Salt Lake City, UT. Purpose: Inflammation plays a key role in the pathophysiology of heart failure (HF). Prior studies have shown correlation between systemic cytokines and adverse outcomes of HF patients. We hypothesized that inflammatory burden could correlate with the ability of the failing human heart to improve its endogenous function after mechanical unloading induced by left ventricular assist devices (LVAD). Methods: We prospectively examined 68 patients supported with durable LVAD. Left ventricular function was serially evaluated using echocardiography with LVAD turn-down. LVAD- induced myocardial functional “response” was defined as a relative increase in left ventricular ejection

fraction (LVEF) > 50%, a final resulting LVEF> 40% and a decrease in LV end-systolic volume > 25% (i.e. “Responders”). LV myocardium was obtained at the time of LVAD implantation. Illumina platform was used for microarray screening of the myocardial tissue. Myocardial mRNA levels of cytokines were quantified by RT-qPCR. Phosphorylated protein levels of transcription factors were measured by Western Blot. Results: Eleven patients met the criteria of response (i.e. 16% “Responders”). Microarray gene expression screening in the 11 Responders versus 11 age-, gender- and HF etiology- matched Non-responders showed that 20% of the differentially expressed genes were involved in inflammatory cellular pathways. The mRNA tissue levels of CCL2, CCL8 and TNFa were significantly decreased in Responders (n= 11) compared to the total cohort of Nonresponders (n= 57). Also, phosphorylated Stat 3, a transcription factor that controls the expression of multiple cytokines was significantly down regulated at the myocardium of Responders (n= 11) vs Non Responders (n= 57) (0.8 ± 0.2 vs 1.9 ± 0.4 AU, respectively, p= 0.02). On the contrary, phosphorylated p65-NFkB was not differentially expressed between the two groups. Conclusion: Cytokine mRNA levels are significantly decreased in the myocardium of Responders suggesting that decreased inflammatory burden correlates with myocardial structural and functional improvement after LVAD unloading. Stat 3 could be a key coordinator of the differential inflammatory response and it could serve as a potential therapeutic target to enhance myocardial recovery following mechanical unloading of the failing heart. 2( 25) Thymosin β 4 and Its Cleavage Product Ac-SDKP Are Down-Regulated in Left Ventricular Myocardium of Patients With Advanced Heart Failure H.N. Sabbah , R.C. Gupta, V. Singh-Gupta.  Medicine, Henry Ford Hospital, Detroit, MI. Purpose: Thymosin β 4 (Tβ 4) is a 43 amino acid peptide and has been shown to promote angiogenesis, suppress pro-inflammatory cytokines and protect cardiomyocytes from apoptosis and oxidative stress injury. The Tβ 4 cleavage product Ac-SDKP is a tetrapeptide (Acetyl-Ser-Asp-Lys-Pro) that has been shown to inhibit collagen production by fibroblasts and collagen deposition in the LV of rats with hypertension or myocardial infarction. In the setting of chronic heart failure (HF), LV dysfunction and chamber remodeling are associated with interstitial fibrosis, reduced capillary density, cardiomyocyte apoptosis and increased production of reactive oxygen species (ROS). We previously showed that both Tβ 4 and Ac-SDKP are down-regulated in dogs with experimentally-induced HGF. This study tested the hypothesis that protein levels of both Tβ 4 and its cleavage product Ac-SDKP are down-regulated in LV myocardium of patients with advanced HF. Methods: Fresh LV tissue was obtained from the LV free wall of 6 explanted failed human hearts (3 with ischemic cardiomyopathy, ICM, and 3 with idiopathic dilated cardiomyopathy, IDC) and from 4 donor hearts (DNR) deemed not suitable for transplantation. Protein levels of Tβ 4 was determined by Western blotting and bands quantified in densitometric units (du). Levels of Ac-SDKP were determined by ELISA and expressed in ng/mg protein. Results: Protein level of Tβ 4 was significantly lower in explanted failing hearts compared to DNR hearts (0.22 ± 0.01 vs. 0.56 ± 0.02 du, p< 0.05). Similarly, levels of Ac-SDKP were significantly lower in explanted failing hearts compared to DNR hearts (85 ± 10 vs. 207 ± 12 ng/mg protein, p< 0.05). The magnitude of down-regulation of Tβ 4 and Ac-SDKP in failing hearts was similar for both ICM and IDC (Tβ 4: ICM 0.24 ± 0.02 vs. IDC 0.20 ± 0.01 du; Ac-SDKP: ICM 84 ± 20 vs. IDC 61 ± 8 ng/mg). Conclusion: Protein levels of Tβ 4 and its cleavage tetrapeptide Ac-SDKP are markedly down-regulated in LV myocardium of explanted failing human hearts regardless of the etiology of HF. These findings are in-line with the reported increase of pro-inflammatory cytokines, interstitial fibrosis, cardiomyocyte apoptosis, and ROS formation as well as reduced capillary density in failing human hearts. The findings support the therapeutic targeting of Tβ 4 and Ac-SDKP as potential treatment for chronic HF. 2( 26) Myocardial Lipid Metabolism in the End-Stage Failing: Heart: Evidence for an Energy-Starved State J.E. Rame ,1 K. Bedi,1 N. Snyder,2 J. Brandimarto,2 C. Mesaros,2 E.Y. Birati,1 I.A. Blair,2 K.B. Margulies.1  1Cardiovascular Institute,

S90

The Journal of Heart and Lung Transplantation, Vol 34, No 4S, April 2015

University of Pennsylvania, Philadelphia, PA; 2Center of Cancer Pharmacology, University of Pennsylvania, Philadelphia, PA. Purpose: Adaptive or maladaptive alterations in myocardial metabolism have been described in the failing heart, but studies integrating the metabolic signature of human heart failure are lacking. Methods: We targeted lipid species in the myocardium of lean, non-diabetic patients (N= 16) with end-stage HF at the time of cardiac transplantation and compared abundance to myocardial samples from non-failing non-diabetic donors (N= 18). Frozen samples were evaluated by liquid chromatography and high-resolution mass spectrometry (LC-HRMS) to identify lipid species and further quantitate their abundance. Further analysis was performed to quantitate short chain Acyl-CoA intermediates of the tricarboxylic acid (TCA) cycle with liquid chromatography in tandem mass spec LC MS/MS. Stable isotope labeled essential nutrient in cell culture (SILEC) internal standards for acyl-CoAs were generated using 13C3 15N1 pantotheonate in Hepa1c1c7 cells. Systemic and myocardial ketone bodies were assayed utilizing a commercially available colorimetric assay from Caymen Chemicals (Item #700190). Results: We observed a significant decrease in the majority of lipid species, especially medium and long chain acyl-carnitines in end-stage failing myocardium. Furthermore, we identified a significant decrease in SuccinylCoA (Mean10.5 versus 17.7 pmol/mg, p= 0.009), Propionyl-CoA (0.9 versus 1.8 pmol/mg, p= 0.02) and an increase in ketogenic β -hydroxybutyryl-CoA (Mean BHB-CoA 0.57 versus 0.29 pmol/mg, p= 0.01). The ratio of myocardial Succinyl-CoA to Acetyl-CoA, a potential marker of TCA cycling, is significantly decreased in end-stage heart failure (0.84 versus 1.93, p= 0.005). We identified a decrease in myocardial ketone bodies (Mean 195 µM versus 127 µM, p= 0.03), despite a significant increase in peripheral blood ketones(Mean 145 µM versus 19 µM, p= 0.02) in the non-diabetic end-stage failing patients, as compared to the non-diabetic non-failing donors. Conclusion: End-stage failing myocardium retains a paucity of lipid species, including acyl-carnitines and short chain acyl-CoAs for incorporation in fatty acid oxidation and TCA cycling. A decreased ratio of myocardial to peripheral blood ketones in advanced heart failure suggests active metabolism of ketone bodies in this energetically deprived state.

patients with DM (HFDM+) had lower COX and SCCR activitity, but otherwise showed no further alterations compared to non-diabetic HF counterparts (HFDM-). Obesity, HF etiology or age had also minimal additive effects. Conclusion: In advanced HF, LV mitochondria displayed major dearangement of composition and function compared to controls. However, presence of DM was associated with only minor additional alterations, not supporting indepdendent interaction between DM and HF at the mitochodrial level. 

2( 27) The Effect of Diabetes Mellitus on Cardiac Mitochondria in Patients With End-Stage Heart Failure V. Melenovsky ,1 J. Benes,1 J. Pirk,2 T. Pelikanova,3 T. Mracek,4 H. Nuskova,4 Z. Drahota,4 J. Kovalcikova,4 J. Houstek.4  1Dept.of Cardiology, IKEM, Prague, Czech Republic; 2Cardiac Surgery, IKEM, Prague, Czech Republic; 3Dept. of Diabetology, IKEM, Prague, Czech Republic; 4Department of Bioenergetics, Institute of Physiology, Academy of Sciences of CR, Prague, Czech Republic. Purpose: Abnormalities of mitochondrial function were implicated in pathogenesis of heart failure (HF) and diabetes mellitus (DM). It is unknown, whether presence of DM in patients with HF is associated with an additive adverse effect on myocardial mitochondria and bioenergetics that may serve as a drug target. Methods: Left ventrular free wall myocardium was obtained from 62 consecutive patients undergoing heart transplantation (HF group; LVEF 23±9%, age 51±12y, 80% males, 41/59% CAD/non-CAD, 31% with known DM) and from 20 HF-free organ donors (CON group; LVEF 55±12%, age 41±15y, 55% males) to measure mtDNA concent, respiration (oxygraphy), ezymatic activities and protein abundances (SDS-PAGE western-blots) in homogenates. Results: Compared to CON, HF patients had reduced mtDNA content, reduced activity of citrate synthase (CS), cytochrome-c oxidase (COX), NADH-cytochrome-c (NCCR) and succinate-cytochrome-c (SCCR) oxidoreductase. Oxygraphy confirmed a reduction in COX respiration (−21%, p= 0.01) and succinate-supported respiration (−25%, p= 0.01) in HF. Protein abundace of porin (nuclear DNA-encoded protein of outer mitochondrial membrane) was similar, indicating similar bulk of mitochondrial mass. However, components of respiratory chain complex I (NDUFA9), II (SDH70), III (core2) and V (F1α ) were reduced in HF, paralleled by the reduction in antioxidant enzyme glutathion-reductase (GR) and -peroxidase (GPX). Catalase (CAT) and superoxid-dismutases (SOD) were similar. HF

2( 28) Response to CD34+ Cell Therapy Is Associated With Myocardial Scar Burden in Patients With Ischemic and Non-Ischemic Chronic Heart Failure B. Vrtovec ,1 G. Poglajen,1 G. Zemljic,1 M. Sever,2 M. Cukjati,3 F. Haddad,4 J.C. Wu.4  1Advanced Heart Failure and Transplantation Ctr, UMC Ljubljana, Ljubljana, Slovenia; 2Department of Hematology, UMC Ljubljana, Ljubljana, Slovenia; 3National Blood Transfusion Ctr, Ljubljana, Slovenia; 4Stanford Cardiovascular Institute, Stanford, CA. Purpose: We investigated a correlation between heart failure etiology, electromechanical properties of the myocardium and the response to CD34+ cell therapy in patients with chronic heart failure. Methods: In a prospective study we enrolled 40 patients with ischemic cardiomyopathy (ICM) and 40 with non-ischemic dilated cardiomyopathy (DCM). All patients were NYHA class III and had LVEF less than 40%. Peripheral blood CD34+ cells were mobilized by G-CSF and collected via apheresis. NOGA electroanatomical mapping was performed to measure myocardial viability (unipolar voltage; UV) and regional myocardial contraction (linear shortening; LLS). CD34+ cells were injected transendocardially in the hibernating areas defined as UV greater than 8.3 mV and LLS less than 6%. Patient were followed for 6 months after the procedure; good responders were defined as patients with LVEF increase of at least 5%. Results: At baseline the two groups did not differ with regards to gender (male: 85% in ICM vs. 78% in DCM, P= 0.43), LVEF (27.8±7.1% vs. 29.3±7.5%, P= 0.36), serum creatinine (92±24 μ mol/L vs. 88±23 μ mol/L, P= 0.44), or NT-proBNP levels (2877±4410 pg/mL vs. 2225±2131 pg/mL, P= 0.41). Before stem cell therapy we found no inter-group differences