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Advancing maturation of stem cell-derived cardiac muscle represents a major barrier to progress in cardiac regenerative medicine. Cardiac muscle maturation involves a myriad of gene, protein, and cell-based transitions, spanning across all aspects of cardiac muscle form and function. We focused here on a key developmentally controlled transition in the cardiac sarcomere, the functional unit of the heart. Using a gene-editing platform, human induced pluripotent stem cell (hiPSCs) were engineered with a drug-inducible expression cassette driving the adult cardiac troponin I (cTnI) regulatory isoform, a transition shown to be a rate-limiting step in advancing sarcomeric maturation of hiPSC cardiac muscle (hiPSC-CM) toward the adult state. Findings show that induction of the adult cTnI isoform resulted in the physiological acquisition of adult-like cardiac contractile function in hiPSC-CMs in vitro. Specifically, cTnI induction accelerated relaxation kinetics at baseline conditions, a result independent of alterations in the kinetics of the intracellular Ca2+ transient. In comparison, isogenic unedited hiPSC-CMs had no cTnI induction and no change in relaxation function. Temporal control of adult cTnI isoform induction did not alter other developmentally regulated sarcomere transitions, including myosin heavy chain isoform expression, nor did it affect expression of SERCA2a or phospholamban. Taken together, precision genetic targeting of sarcomere maturation via inducible TnI isoform switching enables physiologically relevant adult myocardium-like contractile adaptations that are essential for beat-to-beat modulation of adult human heart performance. These findings have relevance to hiPSC-CM structure-function and drug-discovery studies in vitro, as well as for potential future clinical applications of physiologically optimized hiPSC-CM in cardiac regeneration/repair.

The integration of in vitro cardiac tissue models, human induced pluripotent stem cells (hiPSCs) and genome-editing tools allows for the enhanced interrogation of physiological phenotypes and recapitulation of disease pathologies. Here, using a cardiac tissue model consisting of filamentous three-dimensional matrices populated with cardiomyocytes derived from healthy wild-type (WT) hiPSCs (WT hiPSC-CMs) or isogenic hiPSCs deficient in the sarcomere protein cardiac myosin-binding protein C (MYBPC3-/- hiPSC-CMs), we show that the WT microtissues adapted to the mechanical environment with increased contraction force commensurate to matrix stiffness, whereas the MYBPC3-/- microtissues exhibited impaired force development kinetics regardless of matrix stiffness and deficient contraction force only when grown on matrices with high fibre stiffness. Under mechanical overload, the MYBPC3-/- microtissues had a higher degree of calcium transient abnormalities, and exhibited an accelerated decay of calcium dynamics as well as calcium desensitization, which accelerated when contracting against stiffer fibres. Our findings suggest that MYBPC3 deficiency and the presence of environmental stresses synergistically lead to contractile deficits in cardiac tissues.

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Background Patients undergoing coronary artery bypass graft surgery (CABGS) may fail to adhere to their treatment regimen for many reasons. Among these, one of the most important reasons for nonadherence is the inadequate training of such patients or training using inappropriate methods. Objective This study aimed to compare the effect of gamification and teach-back training methods on adherence to a therapeutic regimen in patients after CABGS. Methods This randomized clinical trial was conducted on 123 patients undergoing CABGS in Tehran, Iran, in 2019. Training was provided to the teach-back group individually. In the gamification group, an app developed for the purpose was installed on each patient’s smartphone, with training given via this device. The control group received usual care, or routine training. Adherence to the therapeutic regimen was assessed using a questionnaire on adherence to a therapeutic regimen (physical activity and dietary regimen) and an adherence scale as a pretest and a 1-month posttest. Results One-way analysis of variance (ANOVA) for comparing the mean scores of teach-back and gamification training methods showed that the mean normalized scores for the dietary regimen (P Conclusions Based on the results of this study, the use of teach-back and gamification training approaches may be suggested for patients after CABGS to facilitate adherence to the therapeutic regimen. Trial Registration Iranian Registry of Clinical Trials IRCT20111203008286N8; https://en.irct.ir/trial/41507

Rationale: During each beat, cardiac myocytes (CMs) generate the mechanical output necessary for heart function through contractile mechanisms that involve shortening of sarcomeres along myofibrils. Human-induced pluripotent stem cells (hiPSCs) can be differentiated into CMs (hiPSC-CMs) that model cardiac contractile mechanical output more robustly when micropatterned into physiological shapes. Quantifying the mechanical output of these cells enables us to assay cardiac activity in a dish. Objective: We sought to develop a computational platform that integrates analytic approaches to quantify the mechanical output of single micropatterned hiPSC-CMs from microscopy videos. Methods and Results: We micropatterned single hiPSC-CMs on deformable polyacrylamide substrates containing fluorescent microbeads. We acquired videos of single beating cells, of microbead displacement during contractions, and of fluorescently labeled myofibrils. These videos were independently analyzed to obtain parameters that capture the mechanical output of the imaged single cells. We also developed novel methods to quantify sarcomere length from videos of moving myofibrils and to analyze loss of synchronicity of beating in cells with contractile defects. We tested this computational platform by detecting variations in mechanical output induced by drugs and in cells expressing low levels of myosin-binding protein C. Conclusions: Our method can measure the cardiac function of single micropatterned hiPSC-CMs and determine contractile parameters that can be used to elucidate mechanisms that underlie variations in CM function. This platform will be amenable to future studies of the effects of mutations and drugs on cardiac function.

The enteric nervous system (ENS) of the gastrointestinal tract controls many diverse functions, including motility and epithelial permeability. Perturbations in ENS development or function are common, yet there is no human model for studying ENS-intestinal biology and disease. We used a tissue-engineering approach with embryonic and induced pluripotent stem cells (PSCs) to generate human intestinal tissue containing a functional ENS. We recapitulated normal intestinal ENS development by combining human-PSC-derived neural crest cells (NCCs) and developing human intestinal organoids (HIOs). NCCs recombined with HIOs in vitro migrated into the mesenchyme, differentiated into neurons and glial cells and showed neuronal activity, as measured by rhythmic waves of calcium transients. ENS-containing HIOs grown in vivo formed neuroglial structures similar to a myenteric and submucosal plexus, had functional interstitial cells of Cajal and had an electromechanical coupling that regulated waves of propagating contraction. Finally, we used this system to investigate the cellular and molecular basis for Hirschsprung's disease caused by a mutation in the gene PHOX2B. This is, to the best of our knowledge, the first demonstration of human-PSC-derived intestinal tissue with a functional ENS and how this system can be used to study motility disorders of the human gastrointestinal tract.

OBJECTIVES: The aim of the present study was to ascertain whether the length of anterior mitral leaflet second-order chordae (SOC) could be considered as a predictor of the incidence of post-repair systolic anterior motion (SAM) and left ventricular outflow tract obstruction (LVOTO) in patients with myxomatous mitral valve disease. METHODS: With the implementation of preoperative transoesophageal echocardiography (TEE), the length of anterior mitral leaflet SOC, anterior leaflet (AL) and posterior leaflet (PL) as well as the distance from the coaptation point to the septum (C-S distance) before and after mitral valve repair (MVR) surgery were measured in 190 patients, comprising 12 who developed SAM and 178 who did not. RESULTS: The results revealed that, in patients who developed SAM, SOC were significantly higher (2.76 ± 0.15 vs 1.83 ± 0.32 mm, P< 0.001) and the C-S distance was significantly lower (2.18 ± 0.36 vs 2.91 ± 0.36 mm, P< 0.001) in comparison to the obtained results for those who did not develop SAM. SOC and the C-S distance were independent risk factors of developing SAM and had the largest area under the receiver operating characteristic (ROC) curve (P< 0.001). With application of a cut-off ROC curve analysis, the cut-offs selected for the two variables of C-S distance and SOC were 2.5 and 2.6, respectively. Sensitivity and specificity of SAM development were 100% [95% confidence interval (CI): 73.5–100] and 87.1% (95% CI: 81.0–91.4) for SOC ≥2.6 and 83.3% (95% CI: 51.6–97.9) and 73.6% (95% CI: 66.4–79.9) for the C-S distance ≤2.5. CONCLUSIONS: The two variables of the second-order chordae and the distance from the coaptation point to the septum were associated with an increased risk of the post-repair systolic anterior motion after mitral valve repair.

Developing technologies for efficient and scalable disruption of gene expression will provide powerful tools for studying gene function, developmental pathways, and disease mechanisms. Here, we develop clustered regularly interspaced short palindromic repeat interference (CRISPRi) to repress gene expression in human induced pluripotent stem cells (iPSCs). CRISPRi, in which a doxycycline-inducible deactivated Cas9 is fused to a KRAB repression domain, can specifically and reversibly inhibit gene expression in iPSCs and iPSC-derived cardiac progenitors, cardiomyocytes, and T lymphocytes. This gene repression system is tunable and has the potential to silence single alleles. Compared with CRISPR nuclease (CRISPRn), CRISPRi gene repression is more efficient and homogenous across cell populations. The CRISPRi system in iPSCs provides a powerful platform to perform genome-scale screens in a wide range of iPSC-derived cell types, dissect developmental pathways, and model disease.

Cardiac and hepatic toxicity result from induced disruption of the functioning of cardiomyocytes and hepatocytes, respectively, which is tightly related to the organization of their subcellular structures. Cellular structure can be analyzed from microscopy imaging data. However, subtle or complex structural changes that are not easily perceived may be missed by conventional image-analysis techniques. Here we report the evaluation of PhenoTox, an image-based deep-learning method of quantifying drug-induced structural changes using human hepatocytes and cardiomyocytes derived from human induced pluripotent stem cells. We assessed the ability of the deep learning method to detect variations in the organization of cellular structures from images of fixed or live cells. We also evaluated the power and sensitivity of the method for detecting toxic effects of drugs by conducting a set of experiments using known toxicants and other methods of screening for cytotoxic effects. Moreover, we used PhenoTox to characterize the effects of tamoxifen and doxorubicin-which cause liver toxicity-on hepatocytes. PhenoTox revealed differences related to loss of cytochrome P450 3A4 activity, for which it showed greater sensitivity than a caspase 3/7 assay. Finally, PhenoTox detected structural toxicity in cardiomyocytes, which was correlated with contractility defects induced by doxorubicin, erlotinib, and sorafenib. Taken together, the results demonstrated that PhenoTox can capture the subtle morphological changes that are early signs of toxicity in both hepatocytes and cardiomyocytes.

Morphogenesis involves interactions of asymmetric cell populations to form complex multicellular patterns and structures comprised of distinct cell types. However, current methods to model morphogenic events lack control over cell-type co-emergence and offer little capability to selectively perturb specific cell subpopulations. Our in vitro system interrogates cell-cell interactions and multicellular organization within human induced pluripotent stem cell (hiPSC) colonies. We examined effects of induced mosaic knockdown of molecular regulators of cortical tension (ROCK1) and cell-cell adhesion (CDH1) with CRISPR interference. Mosaic knockdown of ROCK1 or CDH1 resulted in differential patterning within hiPSC colonies due to cellular self-organization, while retaining an epithelial pluripotent phenotype. Knockdown induction stimulates a transient wave of differential gene expression within the mixed populations that stabilized in coordination with observed self-organization. Mosaic patterning enables genetic interrogation of emergent multicellular properties, which can facilitate better understanding of the molecular pathways that regulate symmetry-breaking during morphogenesis., eLife digest Embryos begin as a collection of similar cells, which progress in stages to form a huge variety of cell types in particular arrangements. These patterns of cells give rise to the different tissues and organs that make up the body. Although we often use ‘model’ organisms such as mice and frogs to study how embryos develop, our species has evolved unique ways to control organ development. Investigating these processes is difficult: we cannot experiment on human embryos, and our development is hard to recreate in test tubes. As a result, we do not fully understand how developing human cells specialize and organize. Libby et al. have now created a new system to study how different genes control cell organization. The system uses human pluripotent stem cells – cells that have the ability to specialize into any type of cell. Some of the stem cells are modified using a technique called inducible CRISPR interference, which makes it possible to reduce the activity of certain genes in these cells. Libby et al. used this technique to investigate how changes to the activity of two genes – called ROCK1 and CDH1 – affect how a mixed group of stem cells organized themselves. Cells that lacked ROCK1 formed bands near the edges of the group. Cells that lacked CDH1 segregated themselves from other cells, forming ‘islands’ inside the main group. The cells retained their ability to specialize into any type of cell after forming these patterns. However, specific groups of cells were more likely to become certain cell types. The method developed by Libby et al. can be used to study a range of complex tissue development and cell organization processes. Future work could create human tissue model systems for research into human disease or drug development.

Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering.

Summary We present a non-invasive method to characterize the function of pluripotent stem-cell-derived cardiomyocytes based on video microscopy and image analysis. The platform, called Pulse, generates automated measurements of beating frequency, beat duration, amplitude, and beat-to-beat variation based on motion analysis of phase-contrast images captured at a fast frame rate. Using Pulse, we demonstrate recapitulation of drug effects in stem-cell-derived cardiomyocytes without the use of exogenous labels and show that our platform can be used for high-throughput cardiotoxicity drug screening and studying physiologically relevant phenotypes., Graphical Abstract, Highlights • Non-invasive characterization of cardiomyocytes using video motion analysis • Assessment of single-cell, monolayer, or tissue cardiomyocytes in standard plates • Drug screening by a label-free, contact-free imaging assay, In this article, Maddah and colleagues present a non-invasive method to characterize the function of stem-cell-derived cardiomyocytes based on video microscopy and image analysis. They demonstrate automated measurements of beating frequency, duration, amplitude, and variation and show that the platform can be used for cardiotoxicity drug screening and studying physiologically relevant phenotypes.

A very focused function for lncRNAs The human genome generates many thousands of long noncoding RNAs (lncRNAs). A very small number of lncRNAs have been shown to be functional. Liu et al. carried out a large-scale CRISPR-based screen to assess the function of ∼17,000 lncRNAs in seven different human cell lines. A considerable number (∼500) of the tested lncRNAs influenced cell growth, suggesting biological function. In almost all cases, though, the function was highly cell type—specific, often limited to just one cell type. Science , this issue p. 10.1126/science.aah7111

Background The ideal management of ischemic mitral regurgitation (MR) remains a clinical dilemma because of the suboptimal available therapeutic options. Recently, new concepts have emerged, pointing to the benefits of a patient selection approach when debating the management of moderate ischemic MR. We investigated the predictability of low-dose dobutamine stress echocardiography (DSE) in selecting candidates for CABG with moderate MR for valve repair. Methods From November 2002 to May 2010, 110 candidates for first-time CABG, who were admitted to the cardiac surgery department in Day General Hospital (Tehran, Iran), were enrolled in the present cross-sectional study. DSE was performed for each case before CABG. Those with positive findings underwent CABG alone and those with negative results underwent concomitant CABG and mitral valve repair. The patients were followed up for a minimum of 60 months. Results Of the 110 patients, 47 (42.72%) had positive test results and underwent CABG alone and 63 (57.28%) had negative DSE results and underwent concomitant CABG and mitral valve repair. The MR degree had decreased from 2.8 ± 0.3 preoperatively to 1.46 ± 0.6 early during the hospital stay and 1.9 ± 0.7 during late follow-up in the CABG group. It had decreased from 2.84 ± 0.4 preoperatively to 0.93 ± 0.65 postoperatively but then increased to 1.41 ± 0.9 during late follow-up, for a significant decrease in the combined group ( P Conclusions Despite its utility in selecting CABG patients with moderate ischemic MR for valve repair from a short-term perspective, the use of DSE cannot predict the long-term outcomes of these patients.

BACKGROUND: We prospectively studied a group of patients with myocardial infarction (MI), who were candidates for surgical revascularization, to compare the efficacy of dobutamine gated myocardial SPECT with dobutamine stress echocardiography (DSE) for the detection of myocardial viability. MATERIALS AND METHODS: We investigated 224 segments from 14 patients with MI using resting echocardiography and low dose dobutamine stress echocardiography as well as resting, low and high dose dobutamine stress 99mTc-Sestamibi gated SPECT. RESULTS: In total, 13 men and 1 women with a mean age 54.57 years (range, 43 to 71 years) entered the study. Of the 125 dysfunctional segments, as assessed by ECG-gated examination, 53 (23.66% of total) were hypokinetic at rest, 64 (28.57% of total) were akinetic, and 8 (3.57% of total) were dyskinetic. The number of segments with resting wall motion abnormality (considered viable by low dose dobutamine ECG-gated examination) was significantly greater than those showing a contractile improvement in response to dobutamine in echocardiography (39.2% versus 32.8%, respectively, p < 0.05). In addition, in high dose ECG-gated examination, 42 of the 125 dysfunctional segments (33.6%) were viable. In general, the methods were well correlated. CONCLUSION: We found a good agreement between low dose dobutamine gated SPECT and stress dobutamine echocardiography for the detection of inotropic reserve in infarcted areas.

Dilated cardiomyopathy (DCM) is often complicated by the appearance of functional mitral regurgitation (FMR). Although mitral ring annuloplasty (MAP) is the most widely used surgical procedure for the surgical treatment of FMR, there are still reports of patients who suffer recurrent FMR at later follow-ups. We sought to investigate the efficacy of papillary muscle approximation (PMA) combined with MAP in preventing the recurrence of FMR in high-risk patients.One hundred patients with ischaemic (74%) or non-ischaemic (26%) DCM along with severe (4+/4+) or moderately severe (3+/4+) FMR were enrolled in this prospective, cross-sectional study. According to the interpapillary muscle distance (iPMD) and coaptation depth (CD), the patients were risk stratified as low (iPMD + CD 30 mm, n= 69) and high-risk (iPMD + CD30 mm, n= 31) groups. The low-risk patients underwent only MAP, whereas the high-risk patients underwent MAP plus PMA.After a mean +/- SD follow-up of 40.8 +/- 12.5 months, recurrence of 3+ to 4+ MR was observed in 8 (8.7%) and 7 (11.1%) patients in the annuloplasty group (MAP-only) and one (3.4%) patient in the combination group (MAP plus PMA) (P= 0.428). At the final follow-up, the New York Heart Association (NYHA) function class was 1.57 +/- 0.62 in the annuloplasty group and 1.45 +/- 0.57 in the combination group; there was no significant difference in NYHA function class between the first and final follow-ups (P0.05).iPMD is a valuable index in the riskstratification of the recurrence of post-MAP MR in patients with DCM complicated by FMR.The patients treated with MAP plus PMA had more favourable outcomes and lower recurrence rates than those treated via the traditional route of MAP only.

Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro.

Human pluripotent stem cells (hPS cells) are rapidly emerging as a powerful tool for biomedical discovery. The advent of human induced pluripotent stem cells (hiPS cells) with human embryonic stem (hES)-cell-like properties has led to hPS cells with disease-specific genetic backgrounds for in vitro disease modeling and drug discovery as well as mechanistic and developmental studies. To fully realize this potential, it will be necessary to modify the genome of hPS cells with precision and flexibility. Pioneering experiments utilizing site-specific double-strand break (DSB)-mediated genome engineering tools, including zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), have paved the way to genome engineering in previously recalcitrant systems such as hPS cells. However, these methods are technically cumbersome and require significant expertise, which has limited adoption. A major recent advance involving the clustered regularly interspaced short palindromic repeats (CRISPR) endonuclease has dramatically simplified the effort required for genome engineering and will likely be adopted widely as the most rapid and flexible system for genome editing in hPS cells. In this unit, we describe commonly practiced methods for CRISPR endonuclease genomic editing of hPS cells into cell lines containing genomes altered by insertion/deletion (indel) mutagenesis or insertion of recombinant genomic DNA.

The aim of this study was to investigate the feasibility of performing papillary muscle repositioning (PMR) for subvalvular-sparing mitral valve replacement procedures in patients with ischemic mitral regurgitation and to determine the early and late effects of this procedure on the clinical outcome and left ventricular mechanics.We prospectively randomly allocated 50 patients with severe ischemic mitral regurgitation and left ventricle dysfunction who were candidates for coronary artery bypass graft surgery and mitral valve replacement into a total chordal-sparing mitral valve replacement group or a PMR group. Echocardiography was performed preoperatively, at discharge, and after 3 years to determine the left ventricular dimensions, shape, and function.The reduction in the left ventricle volumes and sphericity index in the PMR group was more significant than that in the other group. With regard to the left ventricular end-systolic and left ventricular end-diastolic volumes, sphericity index, and ejection fraction, the PMR group showed better results (p0.05), but the difference in New York Heart Association functional class after 3 years was not statistically significant between the two groups (p0.05).The PMR technique described herein can dramatically help ischemic patients by affecting the left ventricular shape and function more efficiently compared with the complete retention of the mitral subvalvular apparatus if the mitral valve is to be replaced.

Objective: The gold standard test in the diagnosis of heart transplant rejection is right ventricular (RV) myocardial biopsy, which is an invasive, time-consuming, expensive method. In an effort to find a reliable method to minimise the sequential use of myocardial biopsy, we assessed the main echocardiographic indices for the detection of allograft rejection. Materials and methods: Fifty myocardial specimens were examined in this prospective study, which assessed the prominent echocardiographic parameters propounded by previous studies as indicators of rejection. Prior to biopsy, all the patients underwent preoperative transthoracic echocardiography. The accuracy of the echocardiographic indices was compared with that of myocardial biopsy indices as the gold standard. At three myocardial segments, namely, RV base, interventricular septal (Sep) base and lateral left ventricular (Lat) base, peak systolic strain (RV-S, Lat-S and Sep-S) was measured. In addition, time to systole (TS) was measured at the same three segments, yielding the three variables of RV-TS, Sep-TS and Lat-TS. Results: Our logistic regression model revealed that the four factors of Lat-S (%), Sep-TS (ms), posterior wall thickness (PWT; mm) and left ventricular mass index (LVMI; g m � 2 ) could denote hearttransplantrejection.Wedeviseda newindex,theechorejectionscore,usingthefollowingformula: [(PWT + LVMI) � (Lat-S + Sep-TS)].This new formula has an area under a curve of 0.932 and a cut-off point of 0; it yields a sensitivity of 100.0%, specificity of 71.0%, positive predictive value of 67.9% and a negative predictive value of 100.0%. If the echo rejection score is >0, there is a 67.9% possibility that a cardiac transplant patient is presenting with allograft rejection, while a score � 0 denotes a 100% improbability of rejection. Conclusion: Our proposed method for screening patients at risk of acute cardiac rejection with echo rejection score showed a good sensitivity in detection of graft rejection. However, further study is required to determine if it can be used as an adjunct to the myocardial biopsy. # 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Behcet's disease is a multisystem disorder and classified as "vasculitic syndrome with a wide variety of clinical manifestations." Cardiac involvement is very rare but can occur with different presentations including: pericarditis, cardiomyopathy, endocarditis, endomyocardial fibrosis, intracavitary thrombosis, and coronary artery disease. Great vessel involvement is more common. Recurrent Phlebitis, commonly involving large vessels (superior vena cava, inferior vena cava, hepatic veins) and cerebral veins are the sole presentation in this regard. Arterial involvement is expressed by aneurysm or pseudoaneurysmal formation. Due to the wide variety of cardiovascular manifestations and the resulting high mortality, cardiac surgeons should be familiar with this disease. In this paper we review the articles and introduce our four cases presenting with aneurysm of ascending aorta with free aortic insufficiency, aneurysm of descending aorta, pulmonary artery aneurysm, and pseudoaneurysm of aortic arch.

ObjectiveIn patients with ischemic cardiomyopathy and substantial amounts of dysfunctional but viable myocardium, revascularization cannot always improve the left ventricular ejection fraction. We sought to investigate the interaction between the left ventricular volume and the amount of viable myocardium to predict the left ventricular ejection fraction increase after revascularization.MethodsEighty-five consecutive patients with a depressed left ventricular ejection fraction (mean: 27.3% ± 5.2%) underwent coronary artery bypass grafting after a dobutamine stress echocardiography had determined that they had at least 4 viable segments. Six months after coronary artery bypass grafting, left ventricular ejection fraction and regional wall motion were reassessed.ResultsAlthough the left ventricular ejection fraction was expected to recover more than 5% in all 85 patients after coronary artery bypass grafting, it did not improve in 15 patients (17.6%) despite the presence of viable segments. The likelihood of the left ventricular ejection fraction recovery decreased proportionally with an increase in the left ventricular end-systolic volume. The nonimprovers had a higher left ventricular end-systolic volume (164.2 ± 22.4 mL vs 125.6 ± 23.4 mL, P = .0001). In addition, the number of viable segments during the dobutamine stress echocardiography had a significant correlation with the ejection fraction increase after 6 months (P < .0001). Patients with 6 viable segments showed a good outcome irrespective of their left ventricular end-systolic volume. In patients with fewer than 6 viable segments, left ventricular end-systolic volume was a major factor in the prognosis: Patients with left ventricular end-systolic volume of 145 or more had a poor left ventricular ejection fraction increase and vice versa.ConclusionThe extent of left ventricular remodeling determines the rate of functional improvement after coronary artery bypass grafting. Patients with a high left ventricular end-systolic volume and fewer than 6 viable segments have a lower likelihood of improvement.

There is still controversy about the influence of gender on hospital mortality after coronary artery bypass grafting. We analyzed various risk factors in 1,258 patients undergoing isolated on-pump coronary artery bypass, of whom 19 (1.5%) died in hospital. There were 937 men (74.5%) and 321 women (25.5%). Compared to men, women were older with a higher mean body mass index, twice as many were hypertensive and diabetic, and they had higher serum cholesterol and triglycerides. Men smoked more, had lower ejection fractions, more myocardial infarctions and poorer functional status. Female sex, congestive heart failure, low ejection fraction, diabetes, previous percutaneous interventions and chronic lung disease were more prevalent among the patients who died. These factors were used to form a logistic regression model in which sex did not have an independent influence on hospital mortality. The difference between men and women can be explained by differences in risk factor profile.

Background Ischemic mitral regurgitation (IMR) is a complex lesion to repair, and its successful management requires an understanding of its mechanism and severity. Ring annuloplasty, currently the surgical treatment of choice for IMR, has failure rates as high as 30% in patients with functional IMR. We sought to study the variables that can predict IMR recurrence after ring annuloplasty. Methods This is a prospective study of 114 patients with 3+ to 4+ IMR who underwent coronary artery bypass grafting and mitral valve annuloplasty with acceptable results at an approximately 2-year follow-up. Variables were compared in a failure group, comprising patients with 2+ or higher MR and a nonfailure group, consisting of those with less than +2 MR. Results There were five postoperative in-hospital deaths. During follow-up, 14 patients died and 95 patients were evaluated. After a mean follow-up of 22.2 ± 4.6 months for the nonfailure group and 18.6 ± 5.6 months for the failure group, 23 patients (24.4%) exhibited annuloplasty failure. Some variables had an effect in our univariate analysis, but only interpapillary muscle distance had a relationship with recurrent MR in the multivariate analysis. Mean preoperative interpapillary muscle distance was 15.0 ± 4.0 and 26.5 ± 2.9 in the nonfailure group and failure group, respectively ( p Conclusions Interpapillary muscle distance, as a reliable index of dysfunctional subvalvular apparatus in patients with IMR, can predict late postrepair MR and indicate the need for a procedure complementary to annuloplasty.

Objective: The purpose of this study was to investigate the use of a modified abdominal ultrasound examination, performed as an extension of a routine diagnostic transthoracic echocardiography. This modified examination is arguably a simple, safe, quick, and accurate way to identify patients with abdominal aortic aneurysm (AAA). Methods: This prospective study, conducted over a 6-month period, sought to obtain the maximum diameter of the abdominal aorta through a routine transthoracic echocardiography. Results: In 1285 patients, 1175 abdominal aortas were visualized (91.4%). The prevalence of AAA was 3.8% (45/1175), which increased with age. Six patients, who had diameters more than 5 cm, were referred to a surgeon. In the patients with AAA, left ventricular hypertrophy and left ventricular dilatation were more frequent. Conclusion: Routine screening of the abdominal aorta during transthoracic echocardiography is recommended on account of the prevalence of AAA in unselected and, in particular, older patients. (ECHOCARDIOGRAPHY, Volume 24, August 2007)

Background The aim of this study was to investigate the feasibility of performing papillary muscle repositioning for mitral valve replacement procedures in patients with left ventricular dysfunction and to determine the early and late effects of this procedure on clinical outcome and left ventricular mechanics. Methods One hundred patients with ejection fraction less than 40, who were candidates for isolated surgical correction of mitral insufficiency, had mitral valve replacement and were prospectively randomly assigned to either total chordal-sparing or papillary muscle repositioning. Fifty subjects underwent papillary muscle repositioning (PMR group), and the remaining 50 had complete preservation of all chordal structures with mitral valve replacement (CMVR group). Echocardiography was performed preoperatively, at discharge, and after 2 years to determine dimensions, left ventricular shape, and function. Results End-diastolic and -systolic volumes decreased in both groups initially and continued to decline. Decreasing volumes, however, were more significant in the PMR group, in which the significant decrease in the sphericity index continued for another 2 years. In contrast, the sphericity index in the CMVR group had no significant changes at discharge and at 2 years. In terms of systolic performance, ejection fraction had no significant changes in the CMVR group, whereas ejection fraction significantly increased in the PMR group. Conclusions Papillary muscle repositioning may result in more favorable left ventricular remodeling compared with complete retention of the mitral subvalvular apparatus during mitral valve replacement. It confers a significant early and late advantage by causing significant reductions in the left ventricular chamber volume, sphericity index, and systolic performance.

The harmful effects of smoking on the postsurgical wound healing disturbances have been widely investigated across various surgical procedures. These effects after coronary artery bypass graft (CABG) surgery have been less explored. We aimed to investigate the association of smoking and the wound healing problems in post-CABG patients.We compared the incidence of wound complications in 405 smokers and 405 nonsmokers who underwent an elective CABG surgery. The incidence of leg and sternal wound complications was evaluated during the first 7 d as well as at a 6-wk postoperative visit.One hundred fifty-six leg wound complications were noted in 132 patients (16.3%). The overall rate of leg wound healing disturbances was significantly higher in smokers than those in nonsmokers (odds ratio, 1.47; 95% confidence interval, 1.109-4.019; P = 0.010). The incidence rates of leg wound edge necrosis and dehiscence were significantly higher in smokers compared with those in nonsmokers (3.7% versus 0.7%, P = 0.004 and 6.6% versus 0.7%, P0.0001, respectively). We found no significant differences between the incidence of postoperative leg wound infection, hematoma, wound edema, and seroma in active smokers and those who never smoked. Thirty-seven postsurgical sternal wound complications (4.6%) were developed in 33 patients (4.1%). The overall rate of sternal wound healing disturbances was similar between smokers and nonsmokers. There was a trend between the sternal wound dehiscence and smoking (P = 0.03); however, the other sternal wound complications were not associated with smoking.Smoking may contribute to the disturbances of wound healing, especially wound dehiscence, in post-CABG patients.

Drug discovery and development are hampered by high failure rates attributed to the reliance on non-human animal models employed during safety and efficacy testing. A fundamental problem in this inefficient process is that non-human animal models cannot adequately represent human biology. Thus, there is an urgent need for high-content in vitro systems that can better predict drug-induced toxicity. Systems that predict cardiotoxicity are of uppermost significance, as approximately one third of safety-based pharmaceutical withdrawals are due to cardiotoxicty. Here, we present a cardiac microphysiological system (MPS) with the attributes required for an ideal in vitro system to predict cardiotoxicity: i) cells with a human genetic background; ii) physiologically relevant tissue structure (e.g. aligned cells); iii) computationally predictable perfusion mimicking human vasculature; and, iv) multiple modes of analysis (e.g. biological, electrophysiological and physiological). Our MPS is able to keep human induced pluripotent stem cell derived cardiac tissue viable and functional over multiple weeks. Pharmacological studies using the cardiac MPS show half maximal inhibitory/effective concentration values (IC50/EC50) that are more consistent with the data on tissue scale references compared to cellular scale studies. We anticipate the widespread adoption of MPSs for drug screening and disease modeling.

We used a modified technique of a composite graft by moving the valve prosthesis away from the end into the inside of the tube and compared the effectiveness of this surgical method with the standard valved conduits.Through a prospective nonrandomized clinical study between March 2011 and June 2012, we performed replacement of the aortic valve and ascending aorta in 30 consecutive patients using a valved composite graft with a mechanical valve prosthesis. A modified self-assembled valved composite graft was employed in 20 patients (Modified group), while the remaining 10 patients received the standard composite graft (Control group).There was significantly less bleeding in the patients with modified grafts (184 vs. 415 mL, p 0.05). Moreover, the mean transvalvular gradient of the composite graft patients was lower in the modified group than in the control group (9 vs. 14 mmHg, respectively, p 0.05).The modified valve composite graft technique results in good hemodynamics and appears to limit blood loss.

Ascending aorta and aortic arch thrombosis is rare in a young man with no risk factor. Here, we report the case of a young male patient with factor V Leiden mutation who developed ascending aorta and aortic arch thrombosis and subsequent emboli.

The ascending aorta may be the site of origin of systemic embolization of an unidentifiable cause. We report a case in which a free-floating thrombus of an unknown cause was detected in the ascending aorta via transesophageal echocardiography. The removal of this pedunculated thrombus, which was attached onto a macroscopically and histologically mildly atherosclerotic aortic wall, led to an uneventful recovery for the patient.

We present a practical and accurate way to measure artificial chordae length in mitral valve repair. During preoperative transesophageal echocardiography, the distance between the head of the posterior papillary muscle and the mitral annulus plane at the coaptation of the leaflets is measured; this is the length of the new chorda. Every millimeter of braided 4-0 Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) contains two tight reverse knots; therefore, the number of the knots determines the accurate length of the artificial chorda.

We report the case of a 48-year-old woman with a history of transient ischaemic attacks (TIA). The patient was diagnosed with a large patent foramen ovale (PFO), for which she underwent percutaneous PFO closure. Two years postprocedurally, the patient suffered frequent TIA and assessment showed the displacement of the device. The device was surgically removed, and the septum was repaired with a pericardial patch. Afterward, however, the patient experienced repeat TIA. It was discovered that the patient had a pulmonary arteriovenous fistula (PAVF), and a diagnosis of a trauma was made. The PAVF was later coil embolised. This case illustrates the importance of evaluating PFO closure patients for the associated causes of right-to-left shunting.

A 21-year-old man who had suffered an episode of complete heart block 2 months earlier and thus undergone pacemaker implantation presented with syncope. Echocardiography showed cardiac tamponade and raised the suspicion of lead penetration. The effusion was drained. Multi-sliced CT scan confirmed that the right aspect of the pacemaker wire was extracardiac, causing the cardiac tamponade.

We present a novel and efficient non-integrating gene expression system in human embryonic stem cells (hESc) utilizing human artificial chromosomes (HAC), which behave as autonomous endogenous host chromosomes and segregate correctly during cell division. HAC are important vectors for investigating the organization and structure of the kinetochore, and gene complementation. HAC have so far been obtained in immortalized or tumour-derived cell lines, but never in stem cells, thus limiting their potential therapeutic application. In this work, we modified the herpes simplex virus type 1 amplicon system for efficient transfer of HAC DNA into two hESc. The deriving stable clones generated green fluorescent protein gene-expressing HAC at high frequency, which were stably maintained without selection for 3 months. Importantly, no integration of the HAC DNA was observed in the hESc lines, compared with the fibrosarcoma-derived control cells, where the exogenous DNA frequently integrated in the host genome. The hESc retained pluripotency, differentiation and teratoma formation capabilities. This is the first report of successfully generating gene expressing de novo HAC in hESc, and is a significant step towards the genetic manipulation of stem cells and potential therapeutic applications.

Prolonged in vitro culture of human embryonic stem (hES) cells can result in chromosomal abnormalities believed to confer a selective advantage. This potential occurrence has crucial implications for the appropriate use of hES cells for research and therapeutic purposes. In view of this, time-point karyotypic evaluation to assess genetic stability is recommended as a necessary control test to be carried out during extensive 'passaging'. Standard techniques currently used for the cytogenetic assessment of ES cells include G-banding and/or Fluorescence in situ Hybridization (FISH)-based protocols for karyotype analysis, including M-FISH and SKY. Critical for both banding and FISH techniques are the number and quality of metaphase spreads available for analysis at the microscope. Protocols for chromosome preparation from hES and human induced pluripotent stem (hiPS) cells published so far appear to differ considerably from one laboratory to another. Here we present an optimized technique, in which both the number and the quality of chromosome metaphase spreads were substantially improved when compared to current standard techniques for chromosome preparations. We believe our protocol represents a significant advancement in this line of work, and has the required attributes of simplicity and consistency to be widely accepted as a reference method for high quality, fast chromosomal analysis of human ES and iPS cells. © 2011 The Author(s).

Transcatheter aortic valve implantation has become an established alternative treatment method for patients with symptomatic aortic stenosis who are at high risk for conventional aortic valve replacement. Problems, however, persist when using this technique in patients with associated coronary artery disease. We describe a successful case of valve implantation via the transaortic route with simultaneous full revascularization.

After cardiac operations, careful management substantially reduces the risks of negative complications during or after the removal of temporary epicardial pacing wires. Herein, we report the case of a 58-year-old man who, 4 days after undergoing aortic root replacement, developed pericardial tamponade after the removal of temporary epicardial pacing wires. Consequent to the tamponade, a right-to-left shunt developed through a previously undiagnosed patent foramen ovale. The patient underwent emergency surgery to repair myocardium that had ruptured due to the removal of the wires, and he recovered uneventfully.

The initial and long-term benefits of coronary artery bypass grafting depend upon maintaining the coronary blood flow supplied by the graft. In order to devise a scoring system for predicting graft patency, we evaluated presumptive correlations between saphenous vein graft patency and the characteristics of saphenous veins that were used as conduits in coronary revascularization.We prospectively evaluated 1,000 saphenous vein segments that were implanted in 403 consecutive patients who underwent on-pump coronary artery bypass grafting at our hospital from January 2006 through February 2009. Branches, varicosity, diameter, and wall thickness were evaluated, and a scoring system was created in order to obtain a value for each characteristic. The patients were postoperatively monitored for 1 year, and graft patency was then evaluated with the use of 64-slice multidetector computed tomography.Lesions were found in 12.3% of the grafts. All of the evaluated characteristics of the grafts had a significant correlation with saphenous vein graft flow (P0.0001). Using the venous characteristics in our statistical analysis, we devised a formula to obtain a score (range, 4-12) to predict the patency of each graft. A cutoff score of 7 yielded 87.8% sensitivity and 82.8% specificity.Our scoring system has good prognostic value. We believe that it can assist surgeons in choosing the most appropriate conduit and target vessel for coronary artery bypass grafting, especially in high-risk patients who are particularly dependent on blood flow through saphenous vein grafts.

OBJECTIVE One of the mechanisms of development of functional mitral regurgitation after myocardial infarction is the increased papillary muscle distance which results due to ventricle remodeling. The aim of this study was to investigate the long-term effect of papillary muscle approximation (PMA) on the cardiac function of patients with ischemic cardiomyopathy and increased papillary muscle distance. METHODS Thirty patients (22 males; mean age: 57.0 ± 7.4 years) selected for coronary artery bypass grafting (CABG) underwent ventriculoplasty. Additionally, 50% of the study population also underwent PMA (group 1). All the patients had preoperative grade 3 or 4 mitral regurgitation with an inter-papillary muscle distance > 2.5 cm. In group 1, the papillary muscles were drawn together using an encircling loop. Mitral annuloplasty and the Dor procedure were performed in all the patients. Follow-up time was 41.5 ± 5.8 months and 42.7 ± 3.3 months in groups 1 and 2, respectively (p-value=0.49). RESULTS The two groups had no significant difference regarding the annulus diameter, ring size, number of grafts, and concavity area. There was one case of in-hospital mortality in each group, and one patient in group 2 had expired by the last follow-up. Postoperative echocardiography revealed significant changes in the concavity area, ejection fraction, and sphericity index in the PMA group by comparison to group 2 (p-value < 0.05). CONCLUSIONS In patients with ischemic mitral regurgitation and increased papillary muscle distance, PMA as an adjunct to CABG results in better left ventricle function and shape, even at long-term follow-up.

Background: Cardiovascular disease is an important cause among natural causes of death in schizophrenic patients. The metabolic syndrome (MetS) has been associated with an increased risk of morbidity and mortality due to cardiovascular disease. There are limited if any data on prevalence of MetS in Iranian patients with schizophrenia. Methods: Between December 2007 and May 2008, all consecutive patients with schizophrenia hospitalized at our university psychiatry hospital were entered in the study. The prevalence of MetS was evaluated based on the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP-III), the adapted ATP-III guidelines (ATP-III A), and the recently suggested criteria by International Diabetes Federation (IDF). Results: Of the study participants, 223 were men (59.9%) and 149 women (40.1%). Overall prevalence of the MetS according to the different definitions were 27.4% (ATP-III), 37.6% (ATP-III A), and 38.7% (IDF), which was over 30% more than the prevalence of MetS in the Iranian general population. The MetS was much more prevalent in women which mainly related to the fact that women had central obesity more frequently.

Myocardial dysfunction needing inotropic support is a typical complication after on-pump cardiac surgery. In this study, we evaluate the effect of milrinone on patients with ventricular dysfunction undergoing coronary artery bypass graft (CABG).Seventy patients with impaired left ventricular function [left ventricular ejection fraction (LVEF)35%] undergoing on-pump CABG were enrolled. Patients were randomized to receive either an intraoperative bolus of milrinone (50 microg/kg) or saline as placebo followed by a 24-hour infusion of each agent (0.5 microg/kg/min). Hemodynamic parameters and transthoracic echocardiographic measurement of systolic and diastolic functions were the variables evaluated.Serum levels of creatine phosphokinase (CPK), the MB isoenzyme of creatine kinase (CK-MB), occurrence of myocardial ischemia or infarction, and mean duration of using inotropic agents were significantly lower in the milrinone group (p0.05). There were no significant differences between the two groups regarding the development of ventricular arrhythmia, duration of cardiopulmonary bypass, intra-aortic balloon pump and inotropic support requirement, duration of mechanical ventilation, duration of intensive care unit stay and mortality rate. Although mean pre-operative LVEF was significantly lower in the milrinone group, there was no significant difference between post-operative LVEFs.We suggest that perioperative administration of milrinone in patients undergoing on-pump CABG, especially those with low LVEF, is beneficial.

This study was conducted to investigate the prevalence of Chlamydia pneumoniae pathogen inside the atherosclerotic plaque of patients undergoing CABG by using PCR assay and to determine whether there is any association between the presence of bacteria in atherosclerotic lesions and classical coronary risk factors.In a cross-sectional study, 102 patients (20 to 79 years old; 73.5% male) undergoing CABG were evaluated in terms of major coronary risk factors and the presence of Chlamydia pneumoniae.Chlamydia pneumoniae was found in 23.4% of coronary plaque specimens. Of these, two patients had no risk factor and the rest of the patients had 1 to 3 risk factors. Patients with positive PCR were more likely to have hypercholesterolaemia (p = 0.009) and low HDL levels (p = 0.000) in comparison with the PCR-negative group. There were no statistical differences for other risk factors.Our results imply the synergic contribution of Chlamydia pneumoniae DNA and known dyslipidaemia to the development of atherosclerotic lesions in patients undergoing CABG.

Background. Zygomycosis is an opportunistic fungal infection mainly affecting patients with diabetes mellitus, immunodeficiency, and malignancies. The majority of cases in which it has been reported as a posttransplantation complication have been after renal or liver transplantation. There are few instances of rhino-sinusitis and orbital mucormycosis complicating heart transplantation. Case Report. A 38-year-old diabetic man who had undergone heart transplantation returned to the transplantation follow-up clinic 20 days after a successful operation with unilateral periorbital swelling, nasal discharge, and multiple cranial nerve dysfunctions. Multidisciplinary investigations resulted in detection of mucormycosis in the paranasal sinuses and the orbital space, as well as a thrombosis of the cavernous sinus. Surgical ablation of the infected parts, along with antifungal treatment and adjustment of immunosuppressive maintenance, restricted extension of the craniofacial involvement. Allograft function remained undisturbed. Conclusion. Early detection of opportunistic infections in transplant recipients plays a big role in preventing dissemination. Fungal infections, including zygomycosis, should be considered for recipients, especially those with risk factors, such as diabetes, who present with local unusual manifestations. Sinonasal and orbital mucormycosis, if diagnosed in timely fashion, can be managed to reduce mortality. Although devastation of one-side facial and ophthalmic structures was inevitable in this case, the overall outcome was acceptable.

Imprinted genes are commonly clustered in domains across the mammalian genome, suggesting a degree of coregulation via long-range coordination of their monoallelic transcription. The distal end of mouse chromosome 7 (Chr 7) contains two clusters of imprinted genes within a approximately 1 Mb domain. This region is conserved on human 11p15.5 where it is implicated in the Beckwith-Wiedemann syndrome. In both species, imprinted regulation requires two critical cis-acting imprinting centres, carrying different germline epigenetic marks and mediating imprinted expression in the proximal and distal sub-domains. The clusters are separated by a region containing the gene for tyrosine hydroxylase (Th) as well as a high density of short repeats and retrotransposons in the mouse. We have used the Cre-loxP recombination system in vivo to engineer an interstitial deletion of this approximately 280-kb intervening region previously proposed to participate in the imprinting mechanism or to act as a boundary between the two sub-domains. The deletion allele, Del(7AI), is silent with respect to epigenetic marking at the two flanking imprinting centres. Reciprocal inheritance of Del(7AI) demonstrates that the deleted region, which represents more than a quarter of the previously defined imprinted domain, is associated with intrauterine growth restriction in maternal heterozygotes. In homozygotes, the deficiency behaves as a Th null allele and can be rescued pharmacologically by bypassing the metabolic requirement for TH in utero. Our results show that the deleted interval is not required for normal imprinting on distal Chr 7 and uncover a new imprinted growth phenotype.