Cell Therapy Trials in Congenital Heart Disease

Cell Therapy Trials in Congenital Heart Disease

Hidemasa Oh

Preclinical study of intracoronary cardiosphere-derived cell (CDC) infusion in a rat model of right heart failure. A–K, Pulmonary artery (PA) banding was created to induce pressure overload right heart failure in rats (weighing 250–300 g). The left thorax was opened to expose the pulmonary artery. A silk suture was tied tightly around an 18-gauge needle alongside the pulmonary artery, followed by a rapid removal of the needle to leave the pulmonary artery constricted in the lumen equal to the diameter of the needle. Intracoronary infusion was performed 4 weeks after pulmonary artery banding. The ascending aorta and the pulmonary artery were occluded with a snare twice for a 20-s interval, 10 min apart, during which time rats received an infusion of CDCs or vehicle into the aortic root directly. Animals were euthanized at 4 weeks after treatment to obtain immuno-histological data. Masson-trichrome staining and hematoxylin and eosin (H&E) staining are shown. One month after pulmonary artery banding, significant right ventricular hypertrophy and fibrosis were observed. Note that CDC treatment reduced cardiac fibrosis, but not hypertrophy, one month after infusion (F and I). Bars, 2 mm in A to C; 20 μm in D to I. J, Animals were separated into 4 groups: (1) sham-operated animals (n=12), (2) rats subjected to pulmonary artery banding for 4 weeks with vehicle treatment (n=12), and (3 and 4) rats subjected to banding for 4 weeks with 2 doses of CDC infusion (0.5×105 or 1×105 cells: n=12 in each). Cardiac fibrosis induced by right ventricle pressure overload was measured. CDC infusion significantly reduced the fibrotic area in a cell dose-dependent manner. K, CDC treatment did not affect the diameter of myocytes, which are mechanically enlarged by pressure overload. L, Rat CDCs were infected by lentiviral vectors harboring human cytomegalovirus promoter-driven LacZ reporter gene and were subjected to intracoronary transfer into rats 4 weeks after pulmonary artery banding. Clear CDC engraftment could be detected along the endocardium and surrounding capillary vessels where the cells had been injected. M, Cardiomyocytes were stained with α-sarcomeric actin (red). Newly regenerated LacZ-positive cardiac muscle cells could be detected by β-galactosidase staining (green). Substantial cardiomyocyte regeneration was verified 4 weeks after CDC delivery. Bars, 50 μm. N, Engrafted LacZ-positive CDCs were evaluated by X-gal staining and corrected by the number of total nuclei appreciated within the respective area. Fibrotic and nonfibrotic areas were determined by Masson-trichrome staining derived from serial sections. O, Differentiated cardiomyocytes after CDC infusion were verified by the cells coexpressing both α-sarcomeric actin (red) and β-galactosidase (LacZ, green). The frequency of the cells coexpressing α-sarcomeric actin among the β-galactosidase–positive cells is shown. Data are expressed as the means (SD). [Powerpoint File]

Bioresorbable Scaffold: The Emerging Reality and Future Directions

Bioresorbable Scaffold: The Emerging Reality and Future Directions

Yohei Sotomi, Yoshinobu Onuma, Carlos Collet, Erhan Tenekecioglu, Renu Virmani, Neal S. Kleiman, Patrick W. Serruys

Strut thickness and platelet activation. The thick protruding strut disrupts the laminar flow and induces flow disturbances, and thereby endothelial shear stress (ESS) microgradients (upper panel). The shear microgradients can induce the formation of stabilized discoid platelet aggregates, the size of which is directly regulated by the magnitude and spatial distribution of the gradient.72,73 Shear microgradient–dependent platelet aggregation requires 3 principal features: shear acceleration phase, peak shear phase, and shear deceleration phase. During shear acceleration, platelets in the central regions of blood flow exposed to laminar flow (constant physiological shear) are suddenly accelerated through the shear microgradient. During the peak shear phase, a proportion of the discoid platelets that are accelerated into the peak shear zone adhere to exposed thrombogenic surfaces through platelet membrane glycoprotein (GP) Ib/IX/V. Exposure of these platelets to elevated hemodynamic drag leads to the extrusion of thin filamentous membrane tethers. Membrane tether formation initiates discoid platelet adhesion with the thrombogenic surface and also facilitates the recruitment of discoid platelets into the downstream deceleration zone. During the shear deceleration phase, platelets transitioning into the flow deceleration zone experience decreasing hemodynamic drag forces. Reduced shear within this zone progressively favors the formation of integrin αIIbβ3 adhesion contacts. Integrin αIIbβ3 engagement is associated with low-frequency calcium spikes that trigger tether restructuring, leading to the stabilization of discoid platelet aggregates. Ongoing discoid platelet recruitment drives the propagation of the thrombus in the downstream deceleration zone, which may in turn amplify the shear microgradient and promote further platelet aggregation. Thus, the shear microgradients caused by the thick struts induce platelet aggregation, formation of microthrombi with potential embolization, and micromyocardial necrosis (so-called a nidus of thrombus). The magnitude of flow disturbance depends on the degree of protrusion of the strut into the lumen. Therefore, thin struts could be a potential solution for the less flow disturbance and thus less thrombogenic status (lower panel). There is another cascade of von Willebrand factor (VWF)/GPIb activation, namely agglutination-elicited GPIb signaling.73 In contrast to shear stress–induced GPIb-elicited signaling, agglutination-elicited GPIb signaling that activates integrin αIIbβ3 requires thromboxane A2 (TXA2). Agglutination-elicited TXA2 production is independent of Ca2+ influx and mobilization of internal Ca2+ stores. [Powerpoint File]

Bioresorbable Scaffold: The Emerging Reality and Future Directions

Bioresorbable Scaffold: The Emerging Reality and Future Directions

Yohei Sotomi, Yoshinobu Onuma, Carlos Collet, Erhan Tenekecioglu, Renu Virmani, Neal S. Kleiman, Patrick W. Serruys

Design and optical coherence tomography (OCT) appearance of first and next generation bioresorbable scaffolds (BRSs). [Powerpoint File]

Contemporary Approaches to Modulating the Nitric Oxide–cGMP Pathway in Cardiovascular Disease

Contemporary Approaches to Modulating the Nitric Oxide–cGMP Pathway in Cardiovascular Disease

Jan R. Kraehling, William C. Sessa

Mechanism of action of nitric oxide–sensitive guanylate cyclase (NOsGC) stimulators and activators. NOsGC stimulators bind to the enzyme and act in an allosteric manner. NO and NOsGC stimulators enhance the NOsGC activity synergistically. NOsGC activators occupy the heme binding site and work therefore only additively with NO. The oxidation of the heme-Fe2+ to heme-Fe3+ results in a weaker binding of heme to NOsGC, hence allowing the NOsGC activators to occupy the heme binding site easier. The schematic is derived from Zorn and Wells.111 [Powerpoint File]

Contemporary Approaches to Modulating the Nitric Oxide–cGMP Pathway in Cardiovascular Disease

Contemporary Approaches to Modulating the Nitric Oxide–cGMP Pathway in Cardiovascular Disease

Jan R. Kraehling, William C. Sessa

Proteins and enzymes involved in the nitric oxide (NO)-nitric oxide–sensitive guanylate cyclase (NOsGC)–cGMP pathway and its modulators. Key players of the pathway are shown in blue, the positive modulators are shown in yellow, and the negative modulators in purple. Endothelial cells (EC) are shown in green (top), whereas the vascular smooth muscle cell (VSMC) is shown in red (bottom). The space between the 2 cells is called myoendothelial junction (MEJ). cGMP mediates its cellular functions through cGMP-modulated (cyclic nucleotide-gated [CNG]) cation channels, cGMP-dependent protein kinases (cGKs) and cGMP-regulated phosphodiesterases (PDEs). BH4 indicates tetrahydrobiopterin; CAV1, caveolin-1; CYB5R3, NADH-cytochrome b5 reductase 3; eNOS, endothelial nitric oxide synthase (NOS3); Hb2+/Hb3+, hemoglobin α (reduced/oxidized); and PDE, phosphodiesterase. [Powerpoint File]

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Henry Gewirtz, Vasken Dilsizian

Diagrammatic representation of myocardial cell and potential targets of radiotracer imaging and mapping of the surface renin–angiotensin system. ACE indicates angiotensin-converting enzyme; AGT, angiotensinogen; Ang II, angiotensin II; AT1R, angiotensin II type 1 receptor; and AT2R, angiotensin II type 2 receptor. Reproduced with permission from Schindler and Dilsizian.61 Copyright © 2012, Elsevier. [Powerpoint File]

Gut Microbiota in Cardiovascular Health and Disease

Gut Microbiota in Cardiovascular Health and Disease

W.H. Wilson Tang, Takeshi Kitai, Stanley L. Hazen

Gut microbiota and possible molecular pathways linked to cardiovascular and cardiometabolic diseases. BAT indicates brown adipose tissue; FXR, farnesoid X receptor; GLP, glucagon-like peptide; GPR, G-protein–coupled receptor; LPS, lipopolysaccharide; PYY, peptide YY; TLR, toll-like receptor; TMA, trimethylamine; and TMAO, trimethylamine N-oxide. [Powerpoint File]

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Henry Gewirtz, Vasken Dilsizian

Myocyte metabolic pathways outlined for glucose and fatty acid metabolism with focus on the mitochondrion. The electron transport chain (ETC), complexes I–V, is a series of proton pumps. The last of which, complex V, supplies protons to a proton-sensitive ATPase and thereby generates ATP. CPT1,2 indicates carnitine palmitoyltransferase 1,2; FA, fatty acid; PDH, pyruvate dehydrogenase; and TCA, tricarboxylic acid (Krebs cycle). Reproduced with permission from Huss and Kelly.30 Copyright © 2005, American Society for Clinical Investigation. [Powerpoint File]

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Myocardial Viability: Survival Mechanisms and Molecular Imaging Targets in Acute and Chronic Ischemia

Henry Gewirtz, Vasken Dilsizian

Key myocyte organelles and ion channels and their function under conditions of ischemia and reperfusion. Ischemia (left panel) causes influx of Ca2+ and decline in pH, both of which, if not severe, facilitate maintenance of closed mitochondrial permeability transition pore (mPTP). On reperfusion (right panel), key events include restoration of physiological pH, burst of reactive oxygen species (ROS) from mitochondria, release of Ca2+ from the sarcoplasmic reticulum (SR), and opening of mPTP which results in collapse of its Δψ. Reproduced with permission from Hausenloy and Yellon.27 Copyright © 2013, American Society for Clinical Investigation. [Powerpoint File]

Heart Failure in Pediatric Patients With Congenital Heart Disease

Heart Failure in Pediatric Patients With Congenital Heart Disease

Robert B. Hinton, Stephanie M. Ware

Genes causing congenital heart disease (CHD) and cardiomyopathy form a complex network. The network diagrams were generated using ToppCluster (www.toppcluster.cchmc.org) software. Gene lists were derived from clinically available next-generation sequencing panels for cardiomyopathy genes (n=50) and CHD genes (n=44). A, Abstracted cluster network showing a selected subset of features from the following categories: Gene ontology (GO): molecular function; GO: biological processes; GO: cellular component; human phenotype; mouse phenotype; pathway; disease (cardiomyopathy and CHD). The features are color coded by category and connected to cardiomyopathy (white circle) and CHD gene nodes. B, Gene level network with nodes (blue) selected from features in GO: biological processes category. The network illustrates that regulation of cellular component of movement, actin filament-based processes, and cardiac chamber morphogenesis are shared in common between cardiomyopathy and CHD genes, whereas regulation of force of heart contraction and tube development are unshared. [Powerpoint File]

Noninvasive Imaging in Adult Congenital Heart Disease

Noninvasive Imaging in Adult Congenital Heart Disease

Luke J. Burchill, Jennifer Huang, Justin T. Tretter, Abigail M. Khan, Andrew M. Crean, Gruschen R. Veldtman, Sanjiv Kaul, Craig S. Broberg

Liver imaging in Fontan-associated liver disease. A, Contrast computed tomographic scan of upper abdomen in a patient with heterotaxy and a Fontan circulation demonstrating a well-circumscribed tumor measuring 5 cm in diameter in the right lobe of a midline liver (yellow asterix). B, Fluorodeoxyglucose-positron emission tomographic scan in the same patient demonstrating abnormal uptake in the right lobe of the liver in the region of the tumor. [Powerpoint File]

Noninvasive Imaging in Adult Congenital Heart Disease

Noninvasive Imaging in Adult Congenital Heart Disease

Luke J. Burchill, Jennifer Huang, Justin T. Tretter, Abigail M. Khan, Andrew M. Crean, Gruschen R. Veldtman, Sanjiv Kaul, Craig S. Broberg

Three-dimensional (3D) echocardiographic quantification. In this example, left atrial and left ventricular volumes are measured using semiautomated border detection in a 3D echocardiogram. Ejection fraction can be derived without the geometric assumptions that limited 2D-derived measures, such as Simpson biplane and the area–length method. [Powerpoint File]

Current Interventional and Surgical Management of Congenital Heart Disease: Specific Focus on Valvular Disease and Cardiac Arrhythmias

Current Interventional and Surgical Management of Congenital Heart Disease: Specific Focus on Valvular Disease and Cardiac Arrhythmias

Kimberly A. Holst, Sameh M. Said, Timothy J. Nelson, Bryan C. Cannon, Joseph A. Dearani

Schematic representation of the possible lines of ablation to treat macro reentrant atrial tachycardia in the presence of various atrial anomalies associated with complex congenital heart disease. avn indicates atrioventricular node; CS, coronary sinus; FO, foramen ovale; HV, hepatic vein; IVC, inferior vena cava; LAA, left atrial appendage; LSVC, left superior vena cava; MV, mitral valve; PV, pulmonary valve; RAA, right atrial appendage; RSVC, right superior vena cava; TAPVR, total anomalous pulmonary venous return; and TV, tricuspid valve. Reproduced from Mavroudis et al53 with permission of the publisher. Copyright ©2008, The Society of Thoracic Surgeons. [Powerpoint File]

Current Status and Future Potential of Transcatheter Interventions in Congenital Heart Disease

Current Status and Future Potential of Transcatheter Interventions in Congenital Heart Disease

Damien P. Kenny, Ziyad M. Hijazi

Cartoon illustrating possible future strategies for the surgical management of newborns with congenital heart disease (CHD). If CHD is diagnosed prenatally, fetal cells may be harvested and induced pluripotent stem cells (iPS) generated; as an alternative, umbilical cord stem cells can be isolated at the time of birth. When diagnosis of CHD is made after birth or in babies who require a palliative surgical operation soon after birth, stem cells may be isolated from surgical cardiac leftovers. All these types of cells will allow the generation of a tissue-engineered graft endowed with growth and remodeling potential, necessary for the definitive correction of cardiac defects (Taken from Avolio et al99; Illustration Credit: Ben Smith). [Powerpoint File]

Current Status and Future Potential of Transcatheter Interventions in Congenital Heart Disease

Current Status and Future Potential of Transcatheter Interventions in Congenital Heart Disease

Damien P. Kenny, Ziyad M. Hijazi

Series of angiographic images demonstrating hybrid pulmonary valve replacement after plication of the main pulmonary artery in a patient with a significantly dilated right ventricular outflow tract (RVOT) after transannular patch repair of tetralogy of Fallot as an infant. A and B, Initial angiogram demonstrating dilated RVOT measuring 33 mm; (C) RVOT angiogram after main pulmonary artery (MPA) plication and placement of a prestent; and (D) MPA angiogram demonstrating valvular competence with no pulmonary incompetence after Melody valve placement. [Powerpoint File]