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.

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.

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.

Association of Renal Arteriosclerosis With Atherosclerotic Cardiovascular Disease Risk in Lupus Nephritis.

OBJECTIVE: Lupus nephritis (LN) predicts a 9-fold higher atherosclerosis cardiovascular disease (ASCVD) risk, highlighting the urgent need to target ASCVD prevention. Studies in IgA nephropathy reported that severe renal arteriosclerosis (r-ASCL) in diagnostic biopsies strongly predicted ASCVD risk. We recently found that 50% of LN pathology reports overlooked r-ASCL reporting, which could explain prior negative LN ASCVD risk studies. The present study was undertaken to examine associations between a composite of reported and overread r-ASCL and ASCVD events in LN. METHODS: Data were abstracted from all LN patients who underwent diagnostic biopsy between 1994 and 2017, including demographic information, ASCVD risk factors, and pathology reports at the time of LN diagnosis. We manually validated all incident ASCVD events. We overread 25% of the biopsies to grade r-ASCL using the Banff criteria. We supplemented the overread r-ASCL grade, when available, to determine the composite of reported and overread r-ASCL grade. RESULTS: Among 189 incident LN patients, 78% were female, 73% White, and the median age was 25 years. Overall, 31% had any reported r-ASCL, and 7% had moderate-to-severe r-ASCL. After incorporating systematically re-examined r-ASCL grade, the prevalence of any and moderate-to-severe r-ASCL increased to 39% and 12%, respectively. We found 22 incident ASCVD events over 11 years of follow-up. Using a composite of reported and overread r-ASCL grade, we found that severe r-ASCL in diagnostic LN biopsies was associated with 9-fold higher odds of ASCVD. CONCLUSION: Severe r-ASCL can predict ASCVD in LN; therefore, larger studies are required to systematically report r-ASCL and examine ASCVD associations.

Dare to dream? Cell-based therapies for heart failure after DREAM-HF: Review and roadmap for future clinical study.

Clinical trials of cell-based therapies for heart failure have resulted in significant strides forward in our understanding of the potential the failing heart has for regeneration and repair. Yet, two decades on, the need for novel cell-based therapies for heart failure has never been greater. The DREAM-HF trial, which was presented as a late-breaking trial at the American Heart Association Scientific Sessions 2021 did not meet the primary heart failure outcome, but did show a large, clinically significant reduction in major adverse cardiovascular events (MACE) in patients receiving cells, an effect that was most pronounced in patients with evidence of maladaptive inflammation. These results represent an important step forward in our understanding of how cell-based therapies can exert beneficial effects in patients with heart failure and should serve as a guide for future clinical efforts. In light of the results of DREAM-HF, this review serves to provide an understanding of the current state of cell-based therapies for heart failure, as well as to highlight major knowledge gaps and suggest guiding principles for clinical trials of cell therapy going forward. Using the knowledge gained from DREAM-HF along with the trials that preceded it, the potential for breakthrough cell-based therapies for heart failure in the coming decade is immense.

Technical and clinical study of x-ray-based surface echo probe tracking using an attached fiducial apparatus.

PURPOSE: Several types of structural heart intervention (SHI) use information from multiple imaging modalities to complete an interventional task. For example, in transcatheter aortic valve replacement (TAVR), placement and deployment of a bioprosthetic aortic valve in the aorta is primarily guided by x-ray fluoroscopy (XRF), and echocardiography provides visualization of cardiac anatomy and blood flow. However, simultaneous interpretation of independent x-ray and echo displays remains a challenge for the interventionalist. The purpose of this work was to develop a novel echo/x-ray co-registration solution in which volumetric transthoracic echo (TTE) is transformed to the x-ray coordinate system by tracking the three-dimensional (3D) pose of a probe fiducial attachment from its appearance in two-dimensional (2D) x-ray images. METHODS: A fiducial attachment for a commercial TTE probe consisting of rings of high-contrast ball bearings was designed and fabricated. The 3D pose (position and orientation) of the fiducial attachment is estimated from a 2D x-ray image using an algorithm in which a virtual point cloud model of the attachment is iteratively rotated, translated, and forward-projected onto the image until the average sum-of-squares of grayscale values at the projected points is minimized. Fiducial registration error (FRE) and target registration error (TRE) of this approach were evaluated in phantom studies using TAVR-relevant gantry orientations and four standard acoustic windows for the TTE probe. A patient study was conducted to assess the clinical suitability of the fiducial attachment prototype during TTE imaging of patients undergoing SHI. TTE image quality for the task of guiding a transcatheter procedure was evaluated in a reviewer study. RESULTS: The 3D FRE ranged from 0.32 ± 0.03 mm (mean ± SD) to 1.31 ± 0.05 mm, depending on C-arm orientation and probe acoustic window. The 3D TRE ranged from 1.06 ± 0.03 mm to 2.42 ± 0.06 mm. Fiducial pose estimation was stable when >75% of the fiducial markers were visible in the x-ray image. A panel of reviewers graded the presentation of heart valves in TTE images from 48 SHI patients. While valve presentation did not differ significantly between acoustic windows (P > 0.05), the mitral valve did achieve a significantly higher image quality compared to the aortic and tricuspid valves (P < 0.001). Overall, reviewers perceived sufficient image quality in 76.5% of images of the mitral valve, 54.9% of images of the aortic valve, and 48.6% of images of the tricuspid valve. CONCLUSIONS: Fiducial-based tracking of a commercial TTE probe is compatible with clinical SHI workflows and yields 3D target registration error of less than 2.5 mm for a variety of x-ray gantry geometries and echo probe acoustic windows. Although TTE image quality with respect to target valve anatomy was sufficient for the majority of cases examined, prescreening of patients for sufficient TTE quality would be helpful.

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.

Point of care, bone marrow mononuclear cell therapy in ischemic heart failure patients personalized for cell potency: 12-month feasibility results from CardiAMP heart failure roll-in cohort.

AIM: Heart failure following myocardial infarction (MI) is a potentially lethal problem with a staggering incidence. The CardiAMP Heart Failure trial represents the first attempt to personalize marrow-derived cell-based therapy to individuals with cell characteristics associated with beneficial responses in prior trials. Before the initiation of the randomized pivotal trial, an open-label "roll-in cohort" was completed to ensure the feasibility of the protocol's procedures. METHODS: Patients with chronic post-MI heart failure (NYHA class II-III) receiving stable, guideline-directed medical therapy with a left ventricular ejection fraction between 20 and 40% were eligible. Two weeks prior to treatment, a ~ 5 mL bone marrow aspiration was performed to examine "cell potency". On treatment day, a 60 mL bone marrow aspiration, bone marrow mononuclear cell (BM MNC) enrichment and transendocardial injection of 200 million BM MNC's was performed in a single, point of care encounter. Patients were then followed to assess clinical outcomes. RESULTS: The cell potency small volume bone marrow aspirate, the 60 mL bone marrow aspirate, and transendocardial injections were well tolerated in 10 patients enrolled. There were no serious adverse events related to bone marrow aspiration or cell delivery. Improvement in 6-min walk distance was observed at 6 months (+47.8 m, P = 0.01) and trended to improvement at 12 months (+46.4, P = 0.06). Similarly, trends to improved NYHA heart failure functional class, quality of life, left ventricular ejection fraction and recruitment of previously akinetic left ventricular wall segments were observed. CONCLUSION: All CardiAMP HF protocol procedures were feasible and well tolerated. Favorable functional, echo and quality of life trends suggest this approach may offer promise for patients with post MI heart failure. The randomized CardiAMP Heart Failure pivotal trial is underway to confirm the efficacy of this approach. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02438306.

Clinical Safety Profile of Transendocardial Catheter Injection Systems: A Plea for Uniform Reporting.

OBJECTIVES: The aim of this study was to characterize the clinical safety profile of transendocardial injection catheters (TIC) reported in the published literature. BACKGROUND: Transendocardial delivery is a minimally invasive approach to deliver potential therapeutic agents directly into the myocardium. The rate of adverse events across TIC is uncertain. METHODS: A systematic search was performed for trial publications using TIC. Procedure-associated adverse event data were abstracted, pooled and compared across catheters for active treatment and placebo injected patients. The transendocardial injection associated serious adverse events (TEI-SAE) was defined as the composite of death, myocardial infarction, stroke or transient ischemic attack within 30 days and cardiac perforation causing death or requiring evacuation, serious intraprocedural arrhythmias and serious coronary artery or peripheral vascular complications. RESULTS: The search identified 4 TIC systems: a helical needle (HN), an electro-anatomically tracked straight needle (EAM-SN), a straight needle without tracking elements (SN), and a curved needle (CN). Of 1799 patients who underwent transendocardial injections, the combined TEI-SAE was 3.4% across all catheters, and 1.1%, 3.3%, 7.1%, and 8.3% for HN, EAM-SN, SN and CN, respectively. However, TIC procedure duration and post procedural cardiac biomarker levels were reported in only 24% and 36% of published trials, respectively. CONCLUSIONS: Transendocardial injection is associated with varied TEI-SAE but the data are very limited. The HN catheter appeared to be associated with lower TEI-SAE, versus other catheters. Procedure duration and post procedure cardiac biomarker levels were under-reported. Clearly, standardized, procedure-related event reporting for trials involving transcatheter delivery would improve our understanding of complications across different systems.

Cardiac fibroblast derived matrix-educated macrophages express VEGF and IL-6, and recruit mesenchymal stromal cells.

The polarization of monocytes into macrophages that possess anti-inflammatory and pro-angiogenic properties could provide a novel therapeutic strategy for patients who are at a high risk for developing heart failure following myocardial infarction (MI). Here in, we describe a novel method of "educating" monocytes into a distinct population of macrophages that exhibit anti-inflammatory and pro-angiogenic features through a 3-day culture on fibronectin-rich cardiac matrix (CX) manufactured using cultured human cardiac fibroblasts. Our data suggest that CX can educate monocytes into a unique macrophage population termed CX educated macrophages (CXMq) that secrete high levels of VEGF and IL-6. In vitro, CXMq also demonstrate the ability to recruit mesenchymal stromal cells (MSC) with known anti-inflammatory properties. Selective inhibition of fibronectin binding to αVß3 surface integrins on CXMq prevented MSC recruitment. This suggests that insoluble fibronectin within CX is, at least in part, responsible for CXMq conversion.

Induced cardiac progenitor cells repopulate decellularized mouse heart scaffolds and differentiate to generate cardiac tissue.

Native myocardium has limited regenerative potential post injury. Advances in lineage reprogramming have provided promising cellular sources for regenerative medicine in addition to research applications. Recently we have shown that adult mouse fibroblasts can be reprogrammed to expandable, multipotent, induced cardiac progenitor cells (iCPCs) by employing forced expression of five cardiac factors along with activation of canonical Wnt and JAK/STAT signaling. Here we aim to further characterize iCPCs by highlighting their safety, ease of attainability, and functionality within a three-dimensional cardiac extracellular matrix scaffold. Specifically, iCPCs did not form teratomas in contrast to embryonic stem cells when injected into immunodeficient mice. iCPC reprogramming was achieved in wild type mouse fibroblasts without requiring a cardiac-specific reporter, solely utilizing morphological changes to identify, clonally isolate, and expand iCPCs, thus increasing the versatility of this technology. iCPCs also show the ability to repopulate decellularized native heart scaffolds and differentiated into organized structures containing cardiomyocytes, smooth muscle, and endothelial cells. Optical mapping of recellularized scaffolds shows field-stimulated calcium transients that propagate across islands of reconstituted tissue and bipolar local stimulation demonstrates cell-cell coupling within scaffolds. Overall, iCPCs provide a readily attainable, scalable, safe, and functional cell source for a variety of application including drug discovery, disease modeling, and regenerative therapy.

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.

Caveolae-Mediated Activation of Mechanosensitive Chloride Channels in Pulmonary Veins Triggers Atrial Arrhythmogenesis.

Background Atrial fibrillation often occurs in the setting of hypertension and associated atrial dilation with pathologically increased cardiomyocyte stretch. In the setting of atrial dilation, mechanoelectric feedback has been linked to the development of ectopic beats that trigger paroxysmal atrial fibrillation mainly originating from pulmonary veins (PVs). However, the precise mechanisms remain poorly understood. Methods and Results We identify mechanosensitive, swelling-activated chloride ion channels (ICl,swell) as a crucial component of the caveolar mechanosensitive complex in rat and human cardiomyocytes. In vitro optical mapping of rat PV, single rat PV, and human cardiomyocyte patch clamp studies showed that stretch-induced activation of ICl,swell leads to membrane depolarization and decreased action potential amplitude, which trigger conduction discontinuities and both ectopic and reentrant activities within the PV. Reverse transcription quantitative polymerase chain reaction, immunofluorescence, and coimmunoprecipitation studies showed that ICl,swell likely consists of at least 2 components produced by mechanosensitive ClC-3 (chloride channel-3) and SWELL1 (also known as LRRC8A [leucine rich repeat containing protein 8A]) chloride channels, which form a macromolecular complex with caveolar scaffolding protein Cav3 (caveolin 3). Downregulation of Cav3 protein expression and disruption of caveolae structures during chronic hypertension in spontaneously hypertensive rats facilitates activation of ICl,swell and increases PV sensitivity to stretch 10- to 50-fold, promoting the development of atrial fibrillation. Conclusions Our findings identify caveolae-mediated activation of mechanosensitive ICl,swell as a critical cause of PV ectopic beats that can initiate atrial arrhythmias including atrial fibrillation. This mechanism is exacerbated in the setting of chronically elevated blood pressures.

Impact of statins on cellular respiration and de-differentiation of myofibroblasts in human failing hearts.

AIMS: Fibroblast to myofibroblast trans-differentiation with altered bioenergetics precedes cardiac fibrosis (CF). Either prevention of differentiation or promotion of de-differentiation could mitigate CF-related pathologies. We determined whether 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors-statins, commonly prescribed to patients at risk of heart failure (HF)-can de-differentiate myofibroblasts, alter cellular bioenergetics, and impact the human ventricular fibroblasts (hVFs) in HF patients. METHODS AND RESULTS: Either in vitro statin treatment of differentiated myofibroblasts (n = 3-6) or hVFs, isolated from human HF patients under statin therapy (HF + statin) vs. without statins (HF) were randomly used (n = 4-12). In vitro, hVFs were differentiated by transforming growth factor-ß1 (TGF-ß1) for 72 h (TGF-72 h). Differentiation status and cellular oxygen consumption rate (OCR) were determined by α-smooth muscle actin (α-SMA) expression and Seahorse assay, respectively. Data are mean ± SEM except Seahorse (mean ± SD); P < 0.05, considered significant. In vitro, statins concentration-dependently de-differentiated the myofibroblasts. The respective half-maximal effective concentrations were 729 ± 13 nmol/L (atorvastatin), 3.6 ± 1 µmol/L (rosuvastatin), and 185 ± 13 nmol/L (simvastatin). Mevalonic acid (300 µmol/L), the reduced product of HMG-CoA, prevented the statin-induced de-differentiation (α-SMA expression: 31.4 ± 10% vs. 58.6 ± 12%). Geranylgeranyl pyrophosphate (GGPP, 20 µmol/L), a cholesterol synthesis-independent HMG-CoA reductase pathway intermediate, completely prevented the statin-induced de-differentiation (α-SMA/GAPDH ratios: 0.89 ± 0.05 [TGF-72 h + 72 h], 0.63 ± 0.02 [TGF-72 h + simvastatin], and 1.2 ± 0.08 [TGF-72 h + simvastatin + GGPP]). Cellular metabolism involvement was observed when co-incubation of simvastatin (200 nmol/L) with glibenclamide (10 µmol/L), a KATP channel inhibitor, attenuated the simvastatin-induced de-differentiation (0.84 ± 0.05). Direct inhibition of mitochondrial respiration by oligomycin (1 ng/mL) also produced a de-differentiation effect (0.33 ± 0.02). OCR (pmol O2 /min/µg protein) was significantly decreased in the simvastatin-treated hVFs, including basal (P = 0.002), ATP-linked (P = 0.01), proton leak-linked (P = 0.01), and maximal (P < 0.001). The OCR inhibition was prevented by GGPP (basal OCR [P = 0.02], spare capacity OCR [P = 0.008], and maximal OCR [P = 0.003]). Congruently, hVFs from HF showed an increased population of myofibroblasts while HF + statin group showed significantly reduced cellular respiration (basal OCR [P = 0.021], ATP-linked OCR [P = 0.047], maximal OCR [P = 0.02], and spare capacity OCR [P = 0.025]) and myofibroblast differentiation (α-SMA/GAPDH: 1 ± 0.19 vs. 0.23 ± 0.06, P = 0.01). CONCLUSIONS: This study demonstrates the de-differentiating effect of statins, the underlying GGPP sensitivity, reduced OCR with potential activation of KATP channels, and their impact on the differentiation magnitude of hVFs in HF patients. This novel pleiotropic effect of statins may be exploited to reduce excessive CF in patients at risk of HF.

Functional cardiac fibroblasts derived from human pluripotent stem cells via second heart field progenitors.

Cardiac fibroblasts (CFs) play critical roles in heart development, homeostasis, and disease. The limited availability of human CFs from native heart impedes investigations of CF biology and their role in disease. Human pluripotent stem cells (hPSCs) provide a highly renewable and genetically defined cell source, but efficient methods to generate CFs from hPSCs have not been described. Here, we show differentiation of hPSCs using sequential modulation of Wnt and FGF signaling to generate second heart field progenitors that efficiently give rise to hPSC-CFs. The hPSC-CFs resemble native heart CFs in cell morphology, proliferation, gene expression, fibroblast marker expression, production of extracellular matrix and myofibroblast transformation induced by TGFß1 and angiotensin II. Furthermore, hPSC-CFs exhibit a more embryonic phenotype when compared to fetal and adult primary human CFs. Co-culture of hPSC-CFs with hPSC-derived cardiomyocytes distinctly alters the electrophysiological properties of the cardiomyocytes compared to co-culture with dermal fibroblasts. The hPSC-CFs provide a powerful cell source for research, drug discovery, precision medicine, and therapeutic applications in cardiac regeneration.

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.