Human left ventricular cardiac fibroblasts undergo a dynamic shift in secretome and gene expression toward a cardiac myofibroblast phenotype during early passage in typical culture expansion conditions.

Cardiac fibroblasts (CFs) are critical components of the cardiac niche and primarily responsible for assembly and maintenance of the cardiac extracellular matrix (ECM). CFs are increasingly of interest for tissue engineering and drug development applications, as they provide synergistic support to cardiomyocytes through direct cell-to-cell signaling and cell-to-ECM interactions via soluble factors, including cytokines, growth factors and extracellular vesicles. CFs can be activated to a cardiac myofibroblast (CMF) phenotype upon injury or stimulation with transforming growth factor beta 1. Once activated, CMFs assemble collagen-rich ECM, which is vitally important to stabilize scar formation following myocardial infarction, for example. Although there is greater experience with culture expansion of CFs among non-human strains, very little is known about human CF-to-CMF transitions and expression patterns during culture expansion. In this study, we evaluated for shifts in inflammatory and angiogenic expression profiles of human CFs in typical culture expansion conditions. Understanding shifts in cellular expression patterns during CF culture expansion is critically important to establish quality benchmarks and optimize large-scale manufacturing for future clinical applications.

Cultured cardiac fibroblasts and myofibroblasts express Sushi Containing Domain 2 and assemble a unique fibronectin rich matrix.

Cardiac fibroblasts and myofibroblasts assemble and maintain extracellular matrix during normal development and following injury. Culture expansion of these cells yield a bioengineered matrix that could lead to intriguing therapeutic opportunities. For example, we reported that cultured rat cardiac fibroblasts form a matrix that can be used to delivery therapeutic stem cells. Furthermore, we reported that matrix derived from cultured human cardiac fibroblasts/myofibroblasts converted monocytes into macrophages that express interesting anti-inflammatory and pro-angiogenic properties. Expanding these matrix investigations require characterization of the source cells for quality control. In these efforts, we observed and herein report that Sushi Containing Domain 2 (SUSD2) is a novel and consistent marker for cultured human cardiac fibroblast and myofibroblasts.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association.

BACKGROUND AND PURPOSE: The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF. METHODS: The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations. RESULTS: Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking. CONCLUSIONS: RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

It hurts to swallow! Pseudoachalasia resulting from attempted transcatheter occlusion of a giant congenital coronary artery fistula.

Congenital coronary artery fistula (CAF) is a rare anomaly that can cause heart failure and myocardial ischemia. In recent decades, transcatheter approaches to occlude CAF have emerged as minimally invasive alternatives to surgical ligation. Reported complications with transcatheter CAF occlusion include device embolization and dissection. We report the first case of attempted transcatheter occlusion of a giant CAF that resulted in severe pseudoachalasia.

Transcatheter aortic valve replacement in patients with anomalous left circumflex coronary artery.

The anomalous left circumflex artery can be a risk for coronary stenosis or obstruction during transcatheter aortic valve replacement; however, the best procedural management has not been clarified. We describe three patients with severe aortic valve stenosis as well as anomalous left circumflex artery. In the first patient, a coronary guidewire with balloon was placed before deploying a SAPIEN 3 transcatheter heart valve, as protection from the coronary occlusion or stenosis. For the second and third patients, no coronary protection was used. All procedures were completed safely and no complications were detected at one-year follow-up.

Management of Patients on Non-Vitamin K Antagonist Oral Anticoagulants in the Acute Care and Periprocedural Setting: A Scientific Statement From the American Heart Association.

Non-vitamin K oral anticoagulants (NOACs) are now widely used as alternatives to warfarin for stroke prevention in atrial fibrillation and management of venous thromboembolism. In clinical practice, there is still widespread uncertainty on how to manage patients on NOACs who bleed or who are at risk for bleeding. Clinical trial data related to NOAC reversal for bleeding and perioperative management are sparse, and recommendations are largely derived from expert opinion. Knowledge of time of last ingestion of the NOAC and renal function is critical to managing these patients given that laboratory measurement is challenging because of the lack of commercially available assays in the United States. Idarucizumab is available as an antidote to rapidly reverse the effects of dabigatran. At present, there is no specific antidote available in the United States for the oral factor Xa inhibitors. Prothrombin concentrate may be considered in life-threatening bleeding. Healthcare institutions should adopt a NOAC reversal and perioperative management protocol developed with multidisciplinary input.

The CardiAMP Heart Failure trial: A randomized controlled pivotal trial of high-dose autologous bone marrow mononuclear cells using the CardiAMP cell therapy system in patients with post-myocardial infarction heart failure: Trial rationale and study design.

BACKGROUND: Heart failure following myocardial infarction is a common, disabling, and deadly condition. Direct injection of autologous bone marrow mononuclear cells into the myocardium may result in improved functional recovery, relieve symptoms, and improve other cardiovascular outcomes. METHODS: CardiAMP-HF is a randomized, double-blind, sham-controlled, pivotal trial designed to investigate the safety and efficacy of autologous bone marrow mononuclear cells treatment for patients with medically refractory and symptomatic ischemic cardiomyopathy. The primary end point is change in 6-minute walk distance adjusted for major adverse cardiovascular events at 12 months following treatment. Particularly novel aspects of this trial include a cell potency assay to screen subjects who have bone marrow cell characteristics that suggest a favorable response to treatment, a point-of-care treatment method, a high target dose of 200 million cells, and an efficient transcatheter intramyocardial delivery method that is associated with high cell retention. CONCLUSIONS: This novel approach may lead to a new treatment for those with ischemic heart disease suffering from medically refractory heart failure.

Clinical Trial Design for Investigational Cardio-Regenerative Therapy.

Human trials of cardio-regenerative biologic therapies are being performed worldwide to address a growing, unmet need for durable treatments of cardiovascular disease. A well-constructed clinical trial design for these novel therapies requires careful attention to defining a clear hypothesis, a patient population, and anticipated outcomes. The scope of screening, method of randomization, blinding approach, data monitoring, and statistical analysis plan are the foundational elements that must be addressed in any clinical trial. Although the experience of human trials involving extracellular matrix constructs for cardiovascular disease treatment is limited, numerous lessons have been learned in the field of cell therapy that are translatable across all biologic treatment options. Future progress in this field may include testing combinations of cells, gene-transfer agents, and matrix and identifying treatment responders versus nonresponders.

Cardiopulmonary and histological characterization of an acute rat lung injury model demonstrating safety of mesenchymal stromal cell infusion.

BACKGROUND AIMS: In the field of cellular therapy, potential cell entrapment in the lungs following intravenous administration in a compromised or injured pulmonary system is an important concern that requires further investigation. We developed a rat model of inflammatory and fibrotic lung disease to mimic the human clinical condition of obliterative bronchiolitis (OB) and evaluate the safety of intravenous infusion of mesenchymal stromal cells (MSCs). This model was used to obtain appropriate safety information and functional characterization to support the translation of an ex vivo-generated cellular product into human clinical trials. To overcome spontaneous recovery and size limitations associated with current animal models, we used a novel multiple dose bleomycin strategy to induce lasting lung injury in rats. METHODS: Intratracheal instillation of bleomycin was administered to rats on multiple days. MSCs were intravenously infused 7 days apart. Detailed pulmonary function tests including forced expiratory volume, total lung capacity, and invasive hemodynamic measurements were conducted to define the representative disease model and monitor cardiopulmonary hemodynamic consequences of the cell infusion. Post-euthanasia assessments included a thorough evaluation of lung morphology and histopathology. RESULTS: The double dose bleomycin instillation regimen resulted in severe and irreversible lung injury and fibrosis. Cardiopulmonary physiological monitoring reveled that no adverse events could be attributed to the cell infusion process. DISCUSSION: Although our study did not show the infusion of MSCs to result in an improvement in lung function or rescue of damaged tissue this study does confirm the safety of MSC infusion into damaged lungs.

Induced pluripotent stem cells for post-myocardial infarction repair: remarkable opportunities and challenges.

Coronary artery disease with associated myocardial infarction continues to be a major cause of death and morbidity around the world, despite significant advances in therapy. Patients who have large myocardial infarctions are at highest risk for progressive heart failure and death, and cell-based therapies offer new hope for these patients. A recently discovered cell source for cardiac repair has emerged as a result of a breakthrough reprogramming somatic cells to induced pluripotent stem cells (iPSCs). The iPSCs can proliferate indefinitely in culture and can differentiate into cardiac lineages, including cardiomyocytes, smooth muscle cells, endothelial cells, and cardiac progenitors. Thus, large quantities of desired cell products can be generated without being limited by cellular senescence. The iPSCs can be obtained from patients to allow autologous therapy or, alternatively, banks of human leukocyte antigen diverse iPSCs are possible for allogeneic therapy. Preclinical animal studies using a variety of cell preparations generated from iPSCs have shown evidence of cardiac repair. Methodology for the production of clinical grade products from human iPSCs is in place. Ongoing studies for the safety of various iPSC preparations with regard to the risk of tumor formation, immune rejection, induction of arrhythmias, and formation of stable cardiac grafts are needed as the field advances toward the first-in-man trials of iPSCs after myocardial infarction.

Percutaneous mechanical assist for severe cardiogenic shock due to acute right ventricular failure.

Acute right ventricular failure can lead to severe cardiogenic shock and death. Recovery may be achieved with early supportive measures. In many patients, intravenous fluid and inotropic resuscitation is inadequate to improve cardiac output. In these cases, percutaneous mechanical assist may provide a non-surgical bridge to recovery. Herein, we describe a case series of patients with severe, refractory cardiogenic shock due to acute right ventricular failure who received a continuous flow percutaneous ventricular device primarily utilizing the right internal jugular vein for out flow cannula placement.

Bilateral administration of autologous CD133+ cells in ambulatory patients with refractory critical limb ischemia: lessons learned from a pilot randomized, double-blind, placebo-controlled trial.

BACKGROUND AIMS: CD133+ cells confer angiogenic potential and may be beneficial for the treatment of critical limb ischemia (CLI). However, patient selection, blinding methods and end points for clinical trials are challenging. We hypothesized that bilateral intramuscular administration of cytokine-mobilized CD133+ cells in ambulatory patients with refractory CLI would be feasible and safe. METHODS: In this double-blind, randomized sham-controlled trial, subjects received subcutaneous injections of granulocyte colony-stimulating factor (10 µg/kg per day) for 5 days, followed by leukapheresis, and intramuscular administration of 50-400 million sorted CD133+ cells delivered into both legs. Control subjects received normal saline injections, sham leukapheresis and intramuscular injection of placebo buffered solution. Subjects were followed for 1 year. An aliquot of CD133+ cells was collected from each subject to test for genes associated with cell senescence. RESULTS: Seventy subjects were screened, of whom 10 were eligible. Subject enrollment was suspended because of a high rate of mobilization failure in subjects randomly assigned to treatment. Of 10 subjects enrolled (7 randomly assigned to treatment, 3 randomly assigned to control), there were no differences in serious adverse events at 12 months, and blinding was preserved. There were non-significant trends toward improved amputation-free survival, 6-minute walk distance, walking impairment questionnaire and quality of life in subjects randomly assigned to treatment. Successful CD133+ mobilizers expressed fewer senescence-associated genes compared with poor mobilizers. CONCLUSIONS: Bilateral administration of autologous CD133+ cells in ambulatory CLI subjects was safe, and blinding was preserved. However, poor mobilization efficiency combined with high CD133+ senescence suggests futility in this approach.

Topology observing 3D device reconstruction from continuous-sweep limited angle fluoroscopy.

BACKGROUND: Minimally invasive procedures usually require navigating a microcatheter and guidewire through endoluminal structures such as blood vessels and airways to sites of the disease. For numerous clinical applications, two-dimensional (2D) fluoroscopy is the primary modality used for real-time image guidance during navigation. However, 2D imaging can pose challenges for navigation in complex structures. Real-time 3D visualization of devices within the anatomic context could provide considerable benefits for these procedures. Continuous-sweep limited angle (CLA) fluoroscopy has recently been proposed to provide a compromise between conventional rotational 3D acquisitions and real-time fluoroscopy. PURPOSE: The purpose of this work was to develop and evaluate a noniterative 3D device reconstruction approach for CLA fluoroscopy acquisitions, which takes into account endoluminal topology to avoid impossible paths between disconnected branches. METHODS: The algorithm relies on a static 3D roadmap (RM) of vessels or airways, which may be generated from conventional cone beam CT (CBCT) acquisitions prior to navigation. The RM is converted to a graph representation describing its topology. During catheter navigation, the device is segmented from the live 2D projection images using a deep learning approach from which the centerlines are extracted. Rays from the focal spot to detector pixels representing 2D device points are identified and intersections with the RM are computed. Based on the RM graph, a subset of line segments is selected as candidates to exclude device paths through disconnected branches of the RM. Depth localization for each point along the device is then performed by finding the point closest to the previous 3D reconstruction along the candidate segments. This process is repeated as the projection angle changes for each CLA image frame. The approach was evaluated in a phantom study in which a catheter and guidewire were navigated along five pathways within a complex vessel phantom. The result was compared to static cCBCT acquisitions of the device in the final position. RESULTS: The average root mean squared 3D distance between CLA reconstruction and reference centerline was 1.87 ± 0.30 $1.87 \pm 0.30$ mm. The Euclidean distance at the device tip was 2.92 ± 2.35 $2.92 \pm 2.35$ mm. The correct pathway was identified during reconstruction in 100 % $100\%$ of frames ( n = 1475 $n=1475$ ). The percentage of 3D device points reconstructed inside the 3D roadmap was 91.83 ± 2.52 % $91.83 \pm 2.52\%$ with an average distance of 0.62 ± 0.30 $0.62 \pm 0.30$ mm between the device points outside the roadmap and the nearest point within the roadmap. CONCLUSIONS: This study demonstrates the feasibility of reconstructing curvilinear devices such as catheters and guidewires during endoluminal procedures including intravascular and transbronchial interventions using a noniterative reconstruction approach for CLA fluoroscopy. This approach could improve device navigation in cases where the structure of vessels or airways is complex and includes overlapping branches.

Human iPSC-derived Committed Cardiac Progenitors Generate Cardiac Tissue Grafts in a Swine Ischemic Cardiomyopathy Model without Triggering Ventricular Arrhythmias.

BACKGROUND: The adult human heart following a large myocardial infarction is unable to regenerate heart muscle and instead forms scar with the risk of progressive heart failure. Large animal studies have shown that intramyocardial injection of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) following a myocardial infarction result in cell grafts but also ventricular arrhythmias. We hypothesized that intramyocardial injection of committed cardiac progenitor cells (CCPs) derived from iPSCs, combined with cardiac fibroblast-derived extracellular matrix (cECM) to enhance cell retention will: i) form cardiomyocyte containing functional grafts, ii) be free of ventricular arrhythmias and iii) restore left ventricular contractility in a post-myocardial infarction (MI) cardiomyopathy swine model. METHODS: hiPSCs were differentiated using bioreactors and small molecules to produce a population of committed cardiac progenitor cells (CCPs). MI was created using a coronary artery balloon occlusion and reperfusion model in Yucatan mini pigs. Four weeks later, epicardial needle injections of CCPs+cECM were performed in a small initial feasibility cohort, and then transendocardial injections (TEI) of CCPs+cECM, CCPs alone, cECM alone or vehicle control into the peri-infarct region in a larger randomized cohort. A 4-drug immunosuppression regimen was administered to prevent rejection of human CCPs. Arrhythmias were evaluated using implanted event recorders. Magnetic resonance imaging (MRI) and invasive pressure volume assessment were used to evaluate left ventricular anatomic and functional performance, including viability. Detailed histology was performed on the heart to detect human grafts. RESULTS: A scalable biomanufacturing protocol was developed generating CCPs which can efficiently differentiate to cardiomyocytes or endothelial cells in vitro. Intramyocardial delivery of CCPs to post-MI porcine hearts resulted in engraftment and differentiation of CCPs to form ventricular cardiomyocyte rich grafts. There was no significant difference in cardiac MRI-based measured cardiac volumes or function between control, CCP and CCP+cECM groups; however, dobutamine stimulated functional reserve was improved in CCP and CCP+cECM groups. TEI delivery of CCPs with or without cECM did not result in tumors or trigger ventricular arrhythmias. CONCLUSIONS: CCPs are a promising cell source for post-MI heart repair using clinically relevant TEI with a low risk of engraftment ventricular arrhythmias.

Patient preferences for coronary artery bypass graft surgery or percutaneous intervention in multivessel coronary artery disease.

OBJECTIVES: Determine if patients prefer multivessel percutaneous coronary intervention (mv-PCI) over coronary artery bypass graft surgery (CABG) for treatment of symptomatic multivessel coronary artery disease (mv-CAD) despite high 1-year risk. BACKGROUND: Patient risk perception and preference for CABG or mv-PCI to treat medically refractory mv-CAD are poorly understood. We hypothesize that patients prefer mv-PCI instead of CABG even when quoted high mv-PCI risk. METHODS: 585 patients and 31 physicians were presented standardized questionnaires with a hypothetical scenario describing chest pain and medically refractory mv-CAD. CABG or mv-PCI was presented as treatment options. Risk scenarios included variable 1-year risks of death, stroke, and repeat procedures for mv-PCI and fixed risks for CABG. Participants indicated their preference of revascularization method based on the presented risks. We calculated the odds that patients or physicians would favor mv-PCI over CABG across a range of quoted risks of death, stroke, and repeat procedures. RESULTS: For nearly all quoted risks, patients preferred mv-PCI over CABG, even when the risk of death was double the risk with CABG or the risk of repeat procedures was more than three times that for CABG (P < 0.0001). Compared to patients, physicians chose mv-PCI less often than CABG as the risk of death and repeat procedures increased (P < 0.001 and P = 0.004, respectively). CONCLUSION: Patients favor mv-PCI over CABG to treat mv-CAD, even if 1-year risks of death and repeat procedures far exceed risk with CABG. Physicians are more influenced by actual risk and prefer mv-PCI less than patients despite similarly quoted 1-year risks.

Chronic total occlusion and successful drug-eluting stent placement in Takayasu arteritis-induced renal artery stenosis.

Takayasu arteritis-induced renal artery stenosis (TARAS) is a condition rarely described in the literature. Although percutaneous transluminal angioplasty and stenting has been well-described in the treatment of atherosclerotic renal artery stenosis, its role has not been established in non-atherosclerotic TARAS. We report a case of a female, age 17 years, with Takayasu arteritis who presented to the hospital with seizures and hypertensive crisis. A renal angiogram showed chronic total occlusion (CTO) of the left renal artery. Renal angioplasty and stenting was successfully performed after multiple attempts to deliver a wire distal to the CTO. After sequential balloon predilation, a drug-eluting stent was deployed, resulting in full reperfusion of the kidney. The patient's blood pressure improved dramatically, and patency of the stent was demonstrated with magnetic resonance angiography over 9 months after the procedure.

Identifying molecular and functional similarities and differences between human primary cardiac valve interstitial cells and ventricular fibroblasts.

Introduction: Fibroblasts are mesenchymal cells that predominantly produce and maintain the extracellular matrix (ECM) and are critical mediators of injury response. In the heart, valve interstitial cells (VICs) are a population of fibroblasts responsible for maintaining the structure and function of heart valves. These cells are regionally distinct from myocardial fibroblasts, including left ventricular cardiac fibroblasts (LVCFBs), which are located in the myocardium in close vicinity to cardiomyocytes. Here, we hypothesize these subpopulations of fibroblasts are transcriptionally and functionally distinct. Methods: To compare these fibroblast subtypes, we collected patient-matched samples of human primary VICs and LVCFBs and performed bulk RNA sequencing, extracellular matrix profiling, and functional contraction and calcification assays. Results: Here, we identified combined expression of SUSD2 on a protein-level, and MEOX2, EBF2 and RHOU at a transcript-level to be differentially expressed in VICs compared to LVCFBs and demonstrated that expression of these genes can be used to distinguish between the two subpopulations. We found both VICs and LVCFBs expressed similar activation and contraction potential in vitro, but VICs showed an increase in ALP activity when activated and higher expression in matricellular proteins, including cartilage oligomeric protein and alpha 2-Heremans-Schmid glycoprotein, both of which are reported to be linked to calcification, compared to LVCFBs. Conclusion: These comparative transcriptomic, proteomic, and functional studies shed novel insight into the similarities and differences between valve interstitial cells and left ventricular cardiac fibroblasts and will aid in understanding region-specific cardiac pathologies, distinguishing between primary subpopulations of fibroblasts, and generating region-specific stem-cell derived cardiac fibroblasts.

Multimodality image fusion to guide peripheral artery chronic total arterial occlusion recanalization in a swine carotid artery occlusion model: unblinding the interventionalist.

OBJECTIVES: To demonstrate the feasibility of magnetic resonance imaging (MRI) to X-ray fluoroscopy (XRF) image fusion to guide peripheral artery chronic total occlusion (CTO) recanalization. BACKGROUND: Endovascular peripheral artery CTO revascularization is minimally invasive, but challenging, because the occlusion is poorly visualized under XRF. Devices may steer out of the artery, which can lead to severe perforation. Merging preacquired MRI of the CTO to the live XRF display may permit upfront use of aggressive devices and improve procedural outcomes. METHODS: Swine carotid artery CTOs were created using a balloon injury model. Up to 8 weeks later, MRI of the carotid arteries was acquired and segmented to create three-dimensional surface models, which were then registered onto live XRF. CTO recanalization was performed using incrementally aggressive CTO devices (group A) or an upfront aggressive directed laser approach (group B). Procedural success was defined as luminal or subintimal device position without severe perforation. RESULTS: In this swine model, MRI to XRF fusion guidance resulted in a procedural success of 57% in group A and 100% in group B, which compared favorably to 33% using XRF alone. Fluoroscopy time was significantly less for group B (8.5 ± 2.6 min) compared to group A (48.7 ± 23.9 min), P < 0.01. Contrast dose used was similar between groups A and B. CONCLUSIONS: MRI to XRF fusion-guided peripheral artery CTO recanalization is feasible. Multimodality image fusion may permit upfront use of aggressive CTO devices with improved procedural outcomes compared to XRF-guided procedures.