MiR-133 promotes cardiac reprogramming by directly repressing Snai1 and silencing fibroblast signatures.

Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs) by overexpression of cardiac transcription factors or microRNAs. However, induction of functional cardiomyocytes is inefficient, and molecular mechanisms of direct reprogramming remain undefined. Here, we demonstrate that addition of miR-133a (miR-133) to Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Mesp1 and Myocd improved cardiac reprogramming from mouse or human fibroblasts by directly repressing Snai1, a master regulator of epithelial-to-mesenchymal transition. MiR-133 overexpression with GMT generated sevenfold more beating iCMs from mouse embryonic fibroblasts and shortened the duration to induce beating cells from 30 to 10 days, compared to GMT alone. Snai1 knockdown suppressed fibroblast genes, upregulated cardiac gene expression, and induced more contracting iCMs with GMT transduction, recapitulating the effects of miR-133 overexpression. In contrast, overexpression of Snai1 in GMT/miR-133-transduced cells maintained fibroblast signatures and inhibited generation of beating iCMs. MiR-133-mediated Snai1 repression was also critical for cardiac reprogramming in adult mouse and human cardiac fibroblasts. Thus, silencing fibroblast signatures, mediated by miR-133/Snai1, is a key molecular roadblock during cardiac reprogramming.

Successful management of living donor liver transplantation for biliary atresia with single ventricle physiology-from peri-transplant through total cavopulmonary connection: A case report.

Children with single ventricle physiology have complete mixing of the pulmonary and systemic circulations, requiring staged procedures to achieve a separation of these circulations, or Fontan circulation. The single ventricle physiology significantly increases the risk of mortality in children undergoing non-cardiac surgery. As liver transplantation for patients with single ventricle physiology is particularly challenging, only a few reports have been published. We herein report a case of successful LDLTx for an 8-month-old pediatric patient with biliary atresia, heterotaxy, and complex heart disease of single ventricle physiology. The cardiac anomalies included total anomalous pulmonary venous return type IIb, intermediate atrioventricular septal defect, tricuspid regurgitation grade III, coarctation of aorta, interrupted inferior vena cava, bilateral superior vena cava, and polysplenia syndrome. Following LDLTx, the patient sequentially underwent total cavopulmonary shunt + Damus-Kaye-Stansel at 3 years of age and extracardiac total cavopulmonary connection (EC-TCPC) completion at 5 years of age; 7 years have now passed since LDLTx (2 years post-EC-TCPC). We describe the details of the management of LTx in the presence of cardiac anomalies and report the long-term cardiac and liver function, from peri-LDLTx through EC-TCPC completion.

Variable severity of cardiovascular phenotypes in patients with an early-onset form of Marfan syndrome harboring FBN1 mutations in exons 24-32.

A subgroup of patients with Marfan syndrome (MFS) who have mutations in exons 24-32 of the FBN1 gene manifests severe atrioventricular valve insufficiency and skeletal problems as early as the neonatal period. These patients usually die in the first 2 years of life, thus a region between exons 24 and 32 of FBN1 is recognized as a critical region for this neonatal form of MFS (nMFS). Here, we report five consecutive patients who manifested a cardiovascular phenotype until infancy with mutations in the critical region for nMFS. Although three of these patients showed severe mitral regurgitation and died before reaching 1 year of age, the remaining two patients survived for over 5 years under medical and/or surgical interventions. Two splicing mutations and one missense mutation were identified in the three deceased patients, whereas two missense mutations were found in the two survivors. Currently, the clinical severity of patients with early-onset MFS harboring mutations in the critical region for nMFS seem to be more variable than ever thought, and intensive treatments are recommended even in this subgroup of patients with MFS.

Positional desaturation due to persistent left superior vena cava draining into the left atrium.

Persistent left superior vena cava (PLSVC) is a rare congenital anomaly whose prevalence is 0.3 % of general population. The majority of PLSVC drain into right atrium (RA) through the coronary sinus without clinical harm. However, in about 10 % of patients with PLSVC, it drains into left atrium (LA) causing right-to-left shunt. Here, we present a 60-year-old male patient with a PLSVC draining into LA, who developed dyspnea and desaturation depending on the body position after trans-catheter coil embolization of coronary to pulmonary artery fistulas. PLSVC draining into LA should be included in the differential diagnosis of positional desaturation.

Induction of human cardiomyocyte-like cells from fibroblasts by defined factors.

Heart disease remains a leading cause of death worldwide. Owing to the limited regenerative capacity of heart tissue, cardiac regenerative therapy has emerged as an attractive approach. Direct reprogramming of human cardiac fibroblasts (HCFs) into cardiomyocytes may hold great potential for this purpose. We reported previously that induced cardiomyocyte-like cells (iCMs) can be directly generated from mouse cardiac fibroblasts in vitro and vivo by transduction of three transcription factors: Gata4, Mef2c, and Tbx5, collectively termed GMT. In the present study, we sought to determine whether human fibroblasts also could be converted to iCMs by defined factors. Our initial finding that GMT was not sufficient for cardiac induction in HCFs prompted us to screen for additional factors to promote cardiac reprogramming by analyzing multiple cardiac-specific gene induction with quantitative RT-PCR. The addition of Mesp1 and Myocd to GMT up-regulated a broader spectrum of cardiac genes in HCFs more efficiently compared with GMT alone. The HCFs and human dermal fibroblasts transduced with GMT, Mesp1, and Myocd (GMTMM) changed the cell morphology from a spindle shape to a rod-like or polygonal shape, expressed multiple cardiac-specific proteins, increased a broad range of cardiac genes and concomitantly suppressed fibroblast genes, and exhibited spontaneous Ca(2+) oscillations. Moreover, the cells matured to exhibit action potentials and contract synchronously in coculture with murine cardiomyocytes. A 5-ethynyl-2'-deoxyuridine assay revealed that the iCMs thus generated do not pass through a mitotic cell state. These findings demonstrate that human fibroblasts can be directly converted to iCMs by defined factors, which may facilitate future applications in regenerative medicine.

Bilateral banding of malpositioned pulmonary artery branches.

This report presents two rare cases of malpositioned pulmonary artery branches managed by bilateral banding. The left-branch pulmonary artery, originating from and directly superior to the right branch, entered the posterior mediastinum before heading toward the left pulmonary hilum. The ostium of the left branch could not be visualized by midline sternotomy. Therefore, a double-subtraction technique was used to pass the banding tape around the left branch from the right side. The tape location was adjusted and confirmed by intraoperative echocardiography.

Aberrant left subclavian artery sparing in right-sided interrupted aortic arch repair.

A right-sided interrupted aortic arch is rare, and it may have an associated aberrant left subclavian artery (ALSCA). An ALSCA is most often sacrificed at biventricular repair despite the potential danger of poor left upper-extremity growth. We report a case of ALSCA preservation with extensive dissection during aortic arch repair using direct anastomosis.

Reconstruction of an isolated left subclavian artery in a patient with a right aortic arch and tetralogy of Fallot.

An isolated left subclavian artery (ILSA) is very rarely seen in patients with a right aortic arch. This report describes the case of a 2-year-old boy who underwent ILSA reconstruction during repair of the associated tetralogy of Fallot to prevent future subclavian steal syndrome after surgery.

Open anastomosis of extracardiac conduit for total cavopulmonary connection decreases post-operative pleural effusion.

OBJECTIVE: The goal of this study was to see whether the open anastomosis technique using vacuum-assisted venous drainage at the time of the Fontan procedure was associated with decreased post-operative pleural effusion. METHODS: We analysed a subgroup of patients with a functional single ventricle who underwent non-fenestrated total cavopulmonary connection completion with the insertion of an extracardiac conduit as the sole or predominant procedure conducted by a single surgeon at a single institute, using either an open or closed anastomosis technique. RESULTS: Median age and weight were 2.3 years, with a range from 1.3 to 27.6 years and 11.4 kilograms, with a range from 9.7 to 43 kilograms, respectively. The open anastomosis technique was associated with a shorter bypass run (p = 0.015), decreased surgical duration (p = 0.032), fewer pleural effusion days (p = 0.049), and lesser pleural effusion (p = 0.013) than closed anastomosis. Correlation analysis demonstrated a significant relationship between the amount of pleural effusion and surgical duration (correlation efficient, 0.535; p = 0.033). A logistic regression model showed that the open technique was associated with a 20-fold increase in the likelihood of having a total chest tube discharge of less than 300 millilitres (p = 0.027). CONCLUSIONS: The open anastomosis technique shortens operative duration and bypass run, which in turn might contribute to decreased pleural effusion soon after the modified Fontan procedure.

The effect of body weight in infants undergoing ventricular septal defect closure: A report from the Nationwide Japanese Congenital Surgical Database.

OBJECTIVE: In infants with ventricular septal defect (VSD) who undergo surgical intervention, body weight, along with age, is frequently thought to be the decisive predictor of morbidity and mortality after surgery; however, its information on quantitative risk assessment is limited. METHODS: All infants (<1 year old) with a fundamental diagnosis of VSD who underwent surgical VSD closure or pulmonary artery banding between 2012 and 2016 were identified from the Japan Cardiovascular Surgery Database Congenital Section. The outcome of interest was a composite end point of all-cause death and major complications within 30 days after surgery. We evaluated the association between body weight at surgery and composite end point using logistic regression models. RESULTS: A total of 4947 cases were analyzed (median age, 125; interquartile range [IQR], 79-193 days; median body weight, 4.94 [IQR, 4.00-6.00] kg), including 4310 cases (87.1%) treated with surgical VSD closure and 637 (12.9%) treated with pulmonary artery banding. The surgical course was uncomplicated in 94.2% of cases, 23 (0.5%) died, and 283 (5.7%) experienced major complications. The risk of the composite end point was higher along with lower body weight (adjusted odds ratio, 1.56 for every -1 kg; 95% confidence interval, 1.30-1.88; P < .001) and plateaued at body weight of approximately >4.5 kg via smoothing spline curve. Importantly, cases with approximately <4.5 kg of body weight had higher predicted risk regardless of age. CONCLUSIONS: Surgical intervention for infants with VSD was safely performed in contemporary practice; however, caution is warranted in lower body weight infants, particularly for infants with approximately <4.5 kg.

Successful Total Pericardiectomy for Constrictive Pericarditis in the First Series of Japanese Patients With Mulibrey Nanism.

Patients with Mulibrey nanism (MUL) present with growth failure and multiple organ manifestations, and MUL is caused by mutations in TRIM37. In this article, we report on the first case series of Japanese patients with MUL who developed congestive heart failure due to constrictive pericarditis. Our case series suggests that early diagnosis and total pericardiectomy before adherence of the pericardium might provide clinical benefit and better prognosis for MUL.

Direct In Vivo Reprogramming with Sendai Virus Vectors Improves Cardiac Function after Myocardial Infarction.

Direct cardiac reprogramming holds great promise for regenerative medicine. We previously generated directly reprogrammed induced cardiomyocyte-like cells (iCMs) by overexpression of Gata4, Mef2c, and Tbx5 (GMT) using retrovirus vectors. However, integrating vectors pose risks associated with insertional mutagenesis and disruption of gene expression and are inefficient. Here, we show that Sendai virus (SeV) vectors expressing cardiac reprogramming factors efficiently and rapidly reprogram both mouse and human fibroblasts into integration-free iCMs via robust transgene expression. SeV-GMT generated 100-fold more beating iCMs than retroviral-GMT and shortened the duration to induce beating cells from 30 to 10 days in mouse fibroblasts. In vivo lineage tracing revealed that the gene transfer of SeV-GMT was more efficient than retroviral-GMT in reprogramming resident cardiac fibroblasts into iCMs in mouse infarct hearts. Moreover, SeV-GMT improved cardiac function and reduced fibrosis after myocardial infarction. Thus, efficient, non-integrating SeV vectors may serve as a powerful system for cardiac regeneration.

Use of hemoglobin vesicles during cardiopulmonary bypass priming prevents neurocognitive decline in rats.

BACKGROUND: Homologous blood use is considered to be the gold standard for cardiopulmonary bypass (CPB) priming in infants despite exposure of the patient to potential cellular and humoral antigens. However, the use of hemoglobin vesicles (HbVs), artificial oxygen carriers that encapsulate a concentrated hemoglobin solution within phospholipid bilayer membranes, for CPB priming may prevent neurocognitive decline in infants. The goal of this study was to determine whether HbV use offsets hemodilution caused by patient/priming volume-mismatched CPB and thereby prevents the development of postoperative neurocognitive deficits. METHODS AND RESULTS: CPB was established in 28 male Sprague-Dawley rats (age, 14 to 16 weeks; weight, 450 grams) after cannulation of the tail artery and right atrium. The animals were randomly assigned to 1 of 3 groups: sham surgery (n=9), HbV (-) prime (n=10), or HbV (+) prime (n=9). CPB was conducted for 90 minutes at 200 mL/kg per minute. The hematocrit during CPB was 10.0+/-1.2% in the HbV (+) prime group and 9.9+/-1.3% in the HbV (-) prime group (P=not significant). Learning and memory function were evaluated using 2 different maze tests (Maze-1 and Maze-2, in which the arrival times to the target were measured on the first, third, fifth, and seventh postoperative days). Learning and memory function were significantly better in the HbV (+) prime group than in the HbV (-) prime group (Maze-1, P=0.012; Maze-2, P=0.042); there was no difference between the HbV (+) prime and the sham surgery group. CONCLUSIONS: The use of HbV for CPB priming may serve as a substitute for homologous blood to prevent the unacceptable hemodilution and contribute to maintenance of intact neurocognitive function.

Aortic translocation with autologous tissue.

Aortic translocation, although technically demanding, could be an excellent surgical option for d-transposition of the great vessels and left ventricular outflow tract obstruction. We report a modification of the aortic translocation technique that uses autologous tissue. The aortic root is mobilized from the right ventricle with an extension of infundibular free-wall muscle for use in closure of the ventricular septal defect, which is similar to the technique for harvesting pulmonary autograft in the Ross-Konno procedure. Our modification may offer an even better surgical outcome for aortic translocation.

Palliative Mitral Valve Repair During Infancy for Neonatal Marfan Syndrome.

An infant with neonatal Marfan syndrome (nMFS), a condition that is nearly always lethal during infancy, was referred to our hospital with symptoms of congestive heart failure resulting from severe mitral valve insufficiency. During mitral valve repair, the use of an annuloplasty ring was waived until annular dilatation was achieved after 2 palliative mitral valvuloplasty procedures. After the definitive operation, the patient's mitral valve function remained within normal limits until the last follow-up when the patient was 11 years old. To the best of our knowledge, this patient has the longest recorded survival after mitral valve repair.

Heterotopic transplantation of a decellularized and recellularized whole porcine heart.

OBJECTIVES: One of the final treatments for end-stage heart failure is heart transplantation. However, a shortage of donor hearts has created a long waiting list and limited benefits. Our ultimate goal is to create a whole beating heart fabricated on an organ scaffold for human heart transplantation. Here, we successfully performed the first transplantation using a decellularized whole porcine heart with mesenchymal stem cells. METHODS: A porcine heart was harvested following cardiac arrest induced by a high-potassium solution and stored at -80°C for 24 h. The porcine heart was completely decellularized with 1% sodium dodecyl sulphate and 1% Triton X-100 under the control of perfusion pressure (100 mmHg) and maintained at 37°C. A decellularized whole-heart scaffold was sterilized with gamma irradiation. Cultured mesenchymal stem cells were collected and either infused into the ascending aorta or injected directly into the left ventricular wall. Finally, recellularized whole-heart scaffolds were transplanted into pigs under systemic anticoagulation treatment with heparin. Coronary artery angiography of the transplanted heart graft was performed. RESULTS: In our decellularization method, all cellular components were removed, preserving the heart extracellular matrix. Heterotopic transplantations were successfully performed using a decellularized heart and a recellularized heart. The scaffolds were well perfused, without bleeding from the surface or anastomosis site. Coronary angiography revealed a patent coronary artery in both scaffolds. The transplanted decellularized heart was harvested on Day 3. Haematoxylin and eosin staining showed thrombosis in the coronary arteries and migrated inflammatory cells. Haematoxylin and eosin staining of the transplanted recellularized heart showed similar findings, with the exception of injected mesenchymal stem cells. CONCLUSIONS: To the best of our knowledge, this is the first report of heterotopic transplantation of a decellularized whole porcine heart with mesenchymal stem cells. The scaffolds endured surgical procedures. We detected short-term coronary artery perfusion in the transplanted scaffolds by angiography. Future studies should analyse the histological features of transplanted decellularized scaffolds and optimize the system for recellularization to apply this unique technology clinically.

Apico-pulmonary artery conduit repair of congenitally corrected transposition of the great arteries with ventricular septal defect and pulmonary outflow tract obstruction: a 10-year follow-up.

BACKGROUND: In conventional repair of the congenitally corrected transpositions of the great arteries associated with ventricular septal defect and pulmonary outflow tract obstruction, the placement of the left ventricle-pulmonary artery conduit is at risk owing to probable compression by the sternum, heart block, or injury to the mitral anterior papillary muscle. Apical placement of the left ventriculotomy for the inflow conduit rather than in the midportion or base placement may avoid these complications, although this results in a long and winding extracardiac conduit that may be short-lived because of the proliferation of pseudointima. METHODS: Between 1985 and 1990, a nonvalved Dacron woven-fabric graft conduit was placed between the left ventricular apex and pulmonary artery in 5 patients (mean age, 6.2 +/- 1.7 years) who were then followed for at least 10 years. RESULTS: No iatrogenic heart blocks or mitral regurgitation developed. All patients were complaint-free during the follow-up period, although 1 patient who was clinically well died suddenly in the 10th follow-up year. Cardiac catheterization in the 10th follow-up year indicated a pressure gradient of 21 +/- 6 mm Hg across the conduit, and angiography revealed that the conduit diameter was 91% +/- 6% of the original conduit diameter. CONCLUSIONS: The reportedly poor early and late outcomes that occur after a conventional repair of congenitally corrected transpositions of the great arteries associated with ventricular septal defect and pulmonary outflow tract obstruction, which places an extracardiac conduit between the left ventricle and the pulmonary artery, may be partially neutralized by relocating the inflow position to the apex.

Liberal use of tricuspid valve detachment for transatrial ventricular septal defect closure.

BACKGROUND: Although temporary tricuspid valve detachment is useful for improved visualization of ventricular septal defect through right atriotomy, liberal use of this adjunct is not widely supported, mainly because of concerns about iatrogenic complications such as heart blocks and tricuspid valve dysfunction. The objective of this study was to determine whether liberal use of this adjunct can improve operative outcome. METHODS: Between January 1997 and March 2002, trans-atrial closure of isolated ventricular septal defect (conoventricular or canal type) was performed in 87 consecutive patients. Tricuspid valve detachment was used in 4 out of 44 patients (prudent-use group) and 19 out of 43 patients (liberal-use group) in the first and second half of this period, respectively (p = 0.0002). Patient demographics and use of other surgical and cardiopulmonary bypass techniques remained virtually unchanged during this period. RESULTS: In the prudent-use group, there was one operative death with prolonged bypass time and one residual defect that required reoperation; neither of these patients underwent tricuspid valve detachment. All other patients (both groups) were free from mortality and clinically significant complications, including heart block, tricuspid regurgitation, and residual defect. The liberal-use group had shorter cardiopulmonary bypass time than the prudent-use group (59 +/- 14 vs 67 +/- 22 minutes, p = 0.037). CONCLUSIONS: Tricuspid valve detachment should be used liberally for moderate- or even low-difficulty exposure of ventricular septal defect, regardless of patient background, because it is a safe and effective adjunct that can improve speed, programmability, reproducibility, and reliability.

Individualized total cavopulmonary connection technique for patients with asplenia syndrome.

BACKGROUND: Outcomes after univentricular repair for patients with asplenia syndrome remain unsatisfactory, not only because of clinical difficulties in patient selection, but also secondary to technical difficulties in the separation of the systemic and pulmonary circulations, particularly with the rerouting technique for the inferior systemic veins. METHODS: Between February 1995 and May 2000, a total of 14 consecutive patients with asplenia syndrome underwent bidirectional cavopulmonary connection with obliteration of additional pulmonary blood flow, followed by a total cavopulmonary connection. The rerouting technique for inferior systemic venous blood flow was individualized to optimize laminar nonturbulent flow characteristics in the pathway, and to minimize prosthetic load and suture load on the atrial wall. The lateral tunnel or tube conduit technique was used in an extraatrial, intra-extraatrial, or intraatrial fashion. No fenestration was applied. RESULTS: No hospital mortality was observed. Systemic venous flow was evaluated using magnetic resonance angiography, revealing no signs of obstruction, turbulence, or stasis either in or near the reconstructed pathways, irrespective of the rerouting technique. Postoperative catheterization revealed favorable hemodynamics including an inferior vena cava pressure of 13 +/- 2 mm Hg and arterial oxygen saturation of 93.4% +/- 3.5% at room air. All patients have remained free of symptoms, although 1 patient died of acute septic complications 3.5 years after the procedure. CONCLUSIONS: The complexity of cardiac anomalies in asplenia syndrome warrants individualization of the total cavopulmonary connection technique used in reconstruction of the inferior systemic venous pathway. Optimizing flow characteristics in the pathway should be a priority. A staging approach allows suitable selection of candidates for univentricular repair.

The limitation of staged repair in the surgical management of congenital complex heart anomalies with aortic arch obstruction.

OBJECTIVE: Severe aortic arch obstruction including an interrupted aortic arch in congenital complex heart anomalies remains a challenge in surgical management. METHODS: Treatment and outcomes in 75 consecutive patients who underwent an aortic arch repair as the first step of the staged repair protocol between 1975 and 2000 were reviewed. Their ages at repair ranged from 1 day to 8.5 months. RESULTS: Cross-sectional postoperative follow-up data were available in all the patients. The follow-up period ranged from 0 to 27.6 years (mean: 7.3 +/- 7.3 years). There were 20 postoperative hospital deaths (27%) and 7 late deaths. The Kaplan-Meier estimate of survival was 81.3% +/- 4.5% at 1 month, 68.0% +/- 5.4% at 1 year, 65.0% +/- 5.5% at 5 years, 63.1% +/- 5.7% at 10 years, 63.1% +/- 5.7% at 20 years. By Cox regression analysis, body weight of 2.5 kg or less is the only independent determinant of postoperative mortality (p = 0.04, multivariable odds ratio: 2.50, [95% confidence interval: 1.02-6.1]). The aortic arch morphology, the primary cardiac lesion, or date of operation did not reach a statistically significant level to show correlation with mortality. Reintervention to reconstruct the aortic arch was performed at 9 occasions in 8 of the 55 patients who survived the primary operation (14.5%). The Kaplan-Meier estimate of the reintervention-free rate was 91.3% +/- 4.2% at 5 years, 85.5% +/- 5.6% at 10 years, 75.6% +/- 8.2% at 20 years. Using multivariable Cox regression analysis, interrupted aortic arch (versus aortic coarctation) was the only independent predictor of a shorter time to reintervention (p = 0.001, multivariable odds ratio: 16.1, [95% confidence interval: 3.2-80.2]). CONCLUSIONS: The staged repair protocol was associated with significant limitations in patient survival and with the development of recurrent aortic arch obstruction. Thus, a primary repair protocol may serve as an alternate approach, especially in patients with low weight or with an interrupted aortic arch.