Regeneration of Nonhuman Primate Hearts With Human Induced Pluripotent Stem Cell-Derived Cardiac Spheroids.

BACKGROUND: The clinical application of human induced pluripotent stem cell-derived cardiomyocytes (CMs) for cardiac repair commenced with the epicardial delivery of engineered cardiac tissue; however, the feasibility of the direct delivery of human induced pluripotent stem cell-derived CMs into the cardiac muscle layer, which has reportedly induced electrical integration, is unclear because of concerns about poor engraftment of CMs and posttransplant arrhythmias. Thus, in this study, we prepared purified human induced pluripotent stem cell-derived cardiac spheroids (hiPSC-CSs) and investigated whether their direct injection could regenerate infarcted nonhuman primate hearts. METHODS: We performed 2 separate experiments to explore the appropriate number of human induced pluripotent stem cell-derived CMs. In the first experiment, 10 cynomolgus monkeys were subjected to myocardial infarction 2 weeks before transplantation and were designated as recipients of hiPSC-CSs containing 2×107 CMs or the vehicle. The animals were euthanized 12 weeks after transplantation for histological analysis, and cardiac function and arrhythmia were monitored during the observational period. In the second study, we repeated the equivalent transplantation study using more CMs (6×107 CMs). RESULTS: Recipients of hiPSC-CSs containing 2×107 CMs showed limited CM grafts and transient increases in fractional shortening compared with those of the vehicle (fractional shortening at 4 weeks after transplantation: 26.2±2.1%; 19.3±1.8%; P<0.05), with a low incidence of posttransplant arrhythmia. Transplantation of increased dose of CMs resulted in significantly greater engraftment and long-term contractile benefits (fractional shortening at 12 weeks after transplantation: 22.5±1.0%; 16.6±1.1%; P<0.01, left ventricular ejection fraction at 12 weeks after transplantation: 49.0±1.4%; 36.3±2.9%; P<0.01). The incidence of posttransplant arrhythmia slightly increased in recipients of hiPSC-CSs containing 6×107 CMs. CONCLUSIONS: We demonstrated that direct injection of hiPSC-CSs restores the contractile functions of injured primate hearts with an acceptable risk of posttransplant arrhythmia. Although the mechanism for the functional benefits is not fully elucidated, these findings provide a strong rationale for conducting clinical trials using the equivalent CM products.

Real-World Patent Foramen Ovale (PFO) Closure in Japan　- 30-Day Clinical Outcomes From the AmplatzerTM PFO Occluder Japan Post-Marketing Surveillance Study.

BACKGROUND: The AmplatzerTM PFO Occluder was approved for marketing in Japan in May 2019, and the Amplatzer PFO Occluder Japan Post-marketing Surveillance (PFO Japan PMS) study was initiated in December 2019. This analysis presents 30-day clinical outcomes for PFO Japan PMS study patients.Methods and Results: PFO Japan PMS is a prospective single-arm non-randomized multicenter clinical study. Eligible patients were indicated for patent foramen ovale (PFO) closure and underwent an implant attempt with the AmplatzerTM PFO Occluder. Technical success was defined as successful delivery and release of the occluder; procedural success was defined as technical success with no serious adverse events (SAEs) within 1 day of the procedure. The primary safety endpoint includes predefined device- and/or procedure-related SAEs through 30 days after the procedure. From December 2019 to July 2021, 500 patients were enrolled across 53 Japanese sites. The mean (±SD) patient age was 52.7±15.4 years, and 29.8% of patients were aged >60 years. Technical and procedural success rates were both high (99.8% and 98.8%, respectively). Further, there was only one primary safety endpoint event (0.2%): an episode of asymptomatic paroxysmal atrial fibrillation that occurred 26 days after the procedure. CONCLUSIONS: In this real-world Japanese study with almost one-third of patients aged >60 years, PFO closure with the AmplatzerTM PFO Occluder was performed successfully and safely, with a low incidence of procedure-related atrial arrhythmias.

Intracoronary transplantation of pluripotent stem cell-derived cardiomyocytes: Inefficient procedure for cardiac regeneration.

Advances in stem cell biology have facilitated cardiac regeneration, and many animal studies and several initial clinical trials have been conducted using human pluripotent stem cell-derived cardiomyocytes (PSC-CMs). Most preclinical and clinical studies have typically transplanted PSC-CMs via the following two distinct approaches: direct intramyocardial injection or epicardial delivery of engineered heart tissue. Both approaches present common disadvantages, including a mandatory thoracotomy and poor engraftment. Furthermore, a standard transplantation approach has yet to be established. In this study, we tested the feasibility of performing intracoronary administration of PSC-CMs based on a commonly used method of transplanting somatic stem cells. Six male cynomolgus monkeys underwent intracoronary administration of dispersed human PSC-CMs or PSC-CM aggregates, which are called cardiac spheroids, with multiple cell dosages. The recipient animals were sacrificed at 4 weeks post-transplantation for histological analysis. Intracoronary administration of dispersed human PSC-CMs in the cynomolgus monkeys did not lead to coronary embolism or graft survival. Although the transplanted cardiac spheroids became partially engrafted, they also induced scar formation due to cardiac ischemic injury. Cardiac engraftment and scar formation were reasonably consistent with the spheroid size or cell dosage. These findings indicate that intracoronary transplantation of PSC-CMs is an inefficient therapeutic approach.

Cardiac Regenerative Therapy Using Human Pluripotent Stem Cells for Heart Failure: A State-of-the-Art Review.

Heart transplantation (HT) is the only definitive treatment available for patients with end-stage heart failure who are refractory to medical and device therapies. However, HT as a therapeutic option, is limited by a significant shortage of donors. To overcome this shortage, regenerative medicine using human pluripotent stem cells (hPSCs), such as human embryonic stem cells and human-induced pluripotent stem cells (hiPSCs), has been considered an alternative to HT. Several issues, including the methods of large-scale culture and production of hPSCs and cardiomyocytes, the prevention of tumorigenesis secondary to contamination of undifferentiated stem cells and non-cardiomyocytes, and the establishment of an effective transplantation strategy in large-animal models, need to be addressed to fulfill this unmet need. Although post-transplantation arrhythmia and immune rejection remain problems, the ongoing rapid technological advances in hPSC research have been directed toward the clinical application of this technology. Cell therapy using hPSC-derived cardiomyocytes is expected to serve as an integral component of realistic medicine in the near future and is being potentially viewed as a treatment that would revolutionize the management of patients with severe heart failure.

Intracardiac Echocardiography Guidance for Percutaneous Transcatheter Closure of Atrial Septal Defects　- Nationwide Registry Data Analysis.

BACKGROUND: Transesophageal echocardiography (TEE) has been used for percutaneous atrial septal defect (ASD) closure, with intracardiac echocardiography (ICE) guidance recently being introduced.Methods and Results: The Japanese Structural Heart Disease Registry was established by the Japanese Association of Cardiovascular Intervention and Therapeutics. This study analyzed data from the Registry for 2,859 consecutive cases undergoing percutaneous ASD closure between January 2015 and December 2020. ASD closure was performed under ICE guidance (n=519; 18.2%), TEE guidance (n=1,428; 49.9%), or TEE plus ICE guidance ("Both"; n=900 cases; 31.5%). The success rates were similar in the TEE, ICE, and both groups (99.0%, 99.2%, vs. 98.0%, respectively; P=0.054), as were complication rates (1.2%, 0.5%, vs. 2.1%, respectively; P=0.24). In the TEE and Both groups, 92.4% and 79.6% of patients required general anesthesia, compared with only 2.9% of patients in the ICE group (P<0.001). Fluoroscopic time was longer in the ICE and Both groups than in the TEE group (median [interquartile range] 19 [14-28] and 21 [13-30] vs. 12 [8-19] min, respectively; P<0.001). Rim deficiency and larger defect diameter were inversely related, whereas hospital volume was positively related to ICE guidance. CONCLUSIONS: Percutaneous transcatheter ASD closure was as feasible under ICE as under TEE guidance. ICE guidance is used for less challenging cases in high-volume centers in Japan.

Cricopharyngeal muscle origin transection for oropharyngeal dysphagia, a novel surgical technique.

BACKGROUND: Cricopharyngeal myotomy improves pharyngeal dysphagia by resecting the cricopharyngeal muscle. METHODS: Our procedure, cricopharyngeal muscle origin transection (CPM-OT) is performed through a midline skin incision at the cricoid cartilage level under local anesthesia. CONCLUSIONS: Sixteen patients demonstrated preservation of vocal fold movement without laryngeal nerve injury immediately after CPM-OT in the awake state during aspiration prevention surgery using the glottic closure technique. Postoperative videofluoroscopic examination of swallowing revealed the cricopharyngeal bar was absent and pharyngeal passage of the bolus and Food Intake LEVEL Scale was improved in all patients. CPM-OT is a feasible and less invasive treatment option.

Transcatheter retrieval of atrial septal defect and patent ductus arteriosus occluder: a guidance for device retrieval based on comprehensive bench tests.

OBJECTIVES: The aim of this study is to establish a guidance for device retrieval based on comprehensive bench tests. BACKGROUND: Device embolisation remains a major complication in transcatheter closure of atrial septal defect and patent ductus arteriosus. Although percutaneous retrieval is feasible in the majority of cases, surgical retrieval may be required in complicated circumstances. However, the methods of transcatheter device retrieval have not been completely established. METHODS: Bench tests of device retrieval were performed to verify the appropriate retrieval method according to device type/size. The devices used for testing were Amplatzer Septal Occluder (Abbott, Chicago, IL, United States of America), Figulla Flex II (Occlutech GmbH, Jena, Germany), Amplatzer Duct Occluder-I (Abbott), Amplatzer Duct Occluder-II (Abbott), and Amplatzer Vascular Plug-II (Abbott). The retrieval equipment constituted diagnostic catheters (multipurpose catheter and right Judkins catheter, 4-Fr or 5-Fr, Gadelius Medical, Tokyo, Japan), delivery sheath and cables for each device, Amplatz goose neck snares (Medtronic, Minneapolis, MN, United States of America), OSYPKA CATCHER (Osypka ag, Rheinfelden-Herten, Germany), and OSYPKA LASSOS (Osypka). We investigated the retrieval equipment and sheath sizes required for a successful retrieval procedure for variously sized devices. RESULTS: For patent ductus arteriosus devices, the type of snare and the snaring position are considered important. For atrial septal defect devices, simple snare capture or a double-snare technique with a sufficiently large sheath is effective. Special care should be taken when using the OSYPKA CATCHER for device retrieval. CONCLUSIONS: The results of this study may assist in the selection of both capture devices and a retrieval sheath or a catheter for complete retrieval.

Production of functional cardiomyocytes and cardiac tissue from human induced pluripotent stem cells for regenerative therapy.

The emergence of human induced pluripotent stem cells (hiPSCs) has revealed the potential for curing end-stage heart failure. Indeed, transplantation of hiPSC-derived cardiomyocytes (hiPSC-CMs) may have applications as a replacement for heart transplantation and conventional regenerative therapies. However, there are several challenges that still must be overcome for clinical applications, including large-scale production of hiPSCs and hiPSC-CMs, elimination of residual hiPSCs, purification of hiPSC-CMs, maturation of hiPSC-CMs, efficient engraftment of transplanted hiPSC-CMs, development of an injection device, and avoidance of post-transplant arrhythmia and immunological rejection. Thus, we developed several technologies based on understanding of the metabolic profiles of hiPSCs and hiPSC derivatives. In this review, we outline how to overcome these hurdles to realize the transplantation of hiPSC-CMs in patients with heart failure and introduce cutting-edge findings and perspectives for future regenerative therapy.

Iatrogenic Atrial Septal Defect Requiring Transcatheter Closure Following Transcatheter Mitral Valve Repair.

BACKGROUND: Transcatheter mitral valve repair with the MitraClip system has been established in selected high-risk patients. The MitraClip procedure results in a relatively large iatrogenic atrial septal defect (iASD). This study aimed to investigate the prevalence and clinical course of iASD requiring transcatheter closure following the MitraClip procedure.Methods and Results: This study was conducted at all 59 institutions that perform transcatheter mitral valve repair with the MitraClip system in Japan. The data of patients on whom transcatheter iASD closure was performed were collected. Of the 2,722 patients who underwent the MitraClip procedure, 30 (1%) required transcatheter iASD closure. The maximum iASD size was 9±4 mm (range, 3-18 mm). The common clinical course of transcatheter iASD closure was hypoxemia with right-to-left shunt or right-sided heart failure with left-to-right shunt. Of the 30 patients, 22 (73%) required transcatheter closure within 24 h following the MitraClip procedure, including 12 with hypoxemia and 5 with right-sided heart failure complicated with cardiogenic shock. Of the 5 patients, 2 required mechanical circulatory support devices. Twenty-one patients immediately underwent transcatheter iASD closure, and hemodynamic deteriorations were resolved; however, 1 patient died without having undergone transcatheter closure. CONCLUSIONS: Transcatheter iASD closure was required in 1% of patients who underwent the MitraClip procedure. Many of these patients immediately underwent transcatheter iASD closure because of hypoxemia with right-to-left shunt or right-sided heart failure with left-to-right shunt.

Cough-Inducing Method Using a Tartaric Acid Nebulizer for Patients with Silent Aspiration.

The tartaric acid nebulizer is a well-known cough test to evaluate cough function. This study aimed to evaluate the effectiveness of a cough-inducing method using tartaric acid (CiTA). Patients with dysphagia examined by videofluoroscopic examination of swallowing (VF) at a single institution from May 2017 to August 2017 were included in this retrospective observational study. Although undergoing VF, patients who had aspirated without reflexively coughing or who had coughed insufficiently, were instructed to cough voluntarily. Patients who could not cough voluntarily or had expectorated insufficiently underwent the CiTA method. The rate of cough induction and the effectiveness of expectoration using the CiTA method were evaluated. One hundred fifty-four patients (mean age 69.2 ± 16.8 years) were evaluated. Eighty-seven patients aspirated during VF. Of those patients, 15 were able to expectorate via the cough reflex, 18 were able to expectorate with a voluntary cough, and 12 required suctioning for removal of aspirated material. The remaining 42 patients underwent the CiTA method. Thirty-eight patients (90.4%) could reflexively cough, and 30 (71.4%) could expectorate the aspirated material. This novel method, CiTA, was effective for cough induction in patients with dysphagia, especially for those with silent aspiration.

Impaired Left Atrial Function in Patients with Atrial Septal Defect and History of Atrial Fibrillation.

In patients with atrial septal defect (ASD), atrial left-to-right shunting causes left atrial (LA) remodeling and dysfunction, leading to atrial fibrillation (AF). In adults with ASD and concomitant AF, LA function should be evaluated after ASD closure plus AF radiofrequency catheter ablation (RFCA).This multicenter retrospective cohort study included patients who underwent transcatheter ASD closure at one of the four leading hospitals. Patients with a history of AF also underwent preceding RFCA. The association between AF history and LA ejection fraction (EF) (indicating LA global function) at 6-12 months following ASD closure was evaluated. To account for differences in baseline characteristics between patients with and without a history of AF, we conducted the following statistical methods: (1) multivariate regression analysis in the prepropensity score (PS)-matched cohort and (2) univariate comparisons in the PS-matched cohort.Overall, this study included 231 patients (30 with AF history, 201 without). Multiple regression analysis showed that AF history was independently associated with impaired LAEF (ß = -10.425, P < 0.001, model created prior to propensity matching). A one-to-one PS matching (25 pairs) showed that the LAEF at 6-12 months following ASD closure was significantly impaired in patients with ASD and AF history compared to that in patients without history of AF (median LAEF, 37.5% (interquartile range [IQR] 29.4%-48.5%) versus 52.3 [IQR 50.0%-56.6%]; P < 0.001).LA function was impaired in patients with ASD and a history of AF at 6-12 months after successful transcatheter ASD closure and on maintenance of sinus rhythm by RFCA.

Predictors of New-Onset Atrial Tachyarrhythmias After Transcatheter Atrial Septal Defect Closure in Adults.

BACKGROUND: New-onset atrial tachyarrhythmia (ATA) often develops after atrial septal defect (ASD) closure. Its development raises some potential concerns such as stroke and bleeding complications caused by anticoagulant therapy and limited access to the left atrium for catheter ablation. Although it is essential to identify the risk factors of new-onset ATA, few studies have examined these factors. This study investigated unknown risk factors for the development of new-onset ATA after transcatheter ASD closure in patients without a history of ATA. METHODS: A total of 238 patients without a history of ATA, aged ≥18 years and who underwent transcatheter ASD closure at the current hospital were reviewed. Patient characteristics were compared between the groups with and without new-onset ATA. The factors associated with new-onset ATA were examined using univariate and multivariable analyses. RESULTS: Thirteen (13) (5.5%) patients experienced ATA during follow-up (mean, 21±14 months). Compared with patients without new-onset ATA, patients with new-onset ATA were older (48±18 vs 66±11 years; p<0.001) and had high brain natriuretic peptide (BNP) levels (36±36 vs 177±306 pg/mL; p<0.001). On multivariable analysis, BNP ≥40 pg/mL before ASD closure was associated with new-onset ATA after adjusting for age (OR, 4.91; 95% CI, 1.22-19.8; p=0.025). CONCLUSION: Patients with BNP levels >40 pg/mL before transcatheter ASD closure may have a higher risk of developing new-onset ATA.

Selective elimination of undifferentiated human pluripotent stem cells using pluripotent state-specific immunogenic antigen Glypican-3.

Immunogenicity of immature pluripotent stem cells is a topic of intense debate. Immunogenic antigens, which are specific in pluripotent states, have not been described previously. In this study, we identified glypican-3 (GPC3), a known carcinoembryonic antigen, as a pluripotent state-specific immunogenic antigen. Additionally, we validated the applicability of human leukocyte antigen (HLA)-class I-restricted GPC3-reactive cytotoxic T lymphocytes (CTLs) in the removal of undifferentiated pluripotent stem cells (PSCs) from human induced pluripotent stem cell (hiPSC)-derivatives. HiPSCs uniquely express GPC3 in pluripotent states and were rejected by GPC3-reactive CTLs, which were sensitized with HLA-class I-restricted GPC3 peptides. Furthermore, GPC3-reactive CTLs selectively removed undifferentiated PSCs from hiPSC-derivatives in vitro and inhibited tumor formation in vivo. Our results demonstrate that GPC3 works as a pluripotent state-specific immunogenic antigen in hiPSCs and is applicable to regenerative medicine as a method of removing undifferentiated PSCs, which are the main cause of tumor formation.

Cardiac innervation and sudden cardiac death.

Afferent and efferent cardiac neurotransmission via the cardiac nerves intricately modulates nearly all physiological functions of the heart (chronotropy, dromotropy, lusitropy, and inotropy). Afferent information from the heart is transmitted to higher levels of the nervous system for processing (intrinsic cardiac nervous system, extracardiac-intrathoracic ganglia, spinal cord, brain stem, and higher centers), which ultimately results in efferent cardiomotor neural impulses (via the sympathetic and parasympathetic nerves). This system forms interacting feedback loops that provide physiological stability for maintaining normal rhythm and life-sustaining circulation. This system also ensures that there is fine-tuned regulation of sympathetic-parasympathetic balance in the heart under normal and stressed states in the short (beat to beat), intermediate (minutes to hours), and long term (days to years). This important neurovisceral/autonomic nervous system also plays a major role in the pathophysiology and progression of heart disease, including heart failure and arrhythmias leading to sudden cardiac death. Transdifferentiation of neurons in heart failure, functional denervation, cardiac and extracardiac neural remodeling has also been identified and characterized during the progression of disease. Recent advances in understanding the cellular and molecular processes governing innervation and the functional control of the myocardium in health and disease provide a rational mechanistic basis for the development of neuraxial therapies for preventing sudden cardiac death and other arrhythmias. Advances in cellular, molecular, and bioengineering realms have underscored the emergence of this area as an important avenue of scientific inquiry and therapeutic intervention.

Comparison of Clinical Outcomes After Transcatheter vs. Minimally Invasive Cardiac Surgery Closure for Atrial Septal Defect.

BACKGROUND: Percutaneous closure has replaced surgery for the majority of cases of secundum atrial septal defect (ASD). However, technological advances have made contemporary minimally invasive cardiac surgery (MICS) less invasive than conventional surgery. The aim of this study was to compare clinical outcomes of percutaneous closure of secundum ASD with those of contemporary MICS.Methods and Results:We conducted a single-center retrospective study of 354 patients with ASD treated either with the Amplatzer Septal Occluder (134 patients) or MICS (220 patients) between 2000 and 2013. Success rates and the incidence of complications were compared. The success rates were 98% for percutaneous closure and 100% for MICS. There were no deaths in either group. Major complications occurred in 2 patients (1.5%) who underwent percutaneous closure and in 8 patients (3.6%) treated with MICS (P=0.16). Minor complications occurred in 15 patients (11.2%) who underwent percutaneous closure and in 46 patients (20.9%) treated with MICS (P=0.02). On multivariate analysis, MICS (odds ratio [OR]: 2.91, 95% confidence interval [CI]: 1.46-5.81; P=0.002) and age >70 years (OR: 3.50, 95% CI: 1.40-8.75; P=0.008) were independent predictors of complications. CONCLUSIONS: Percutaneous closure and MICS had high success rates without deaths. For ASD patients with a suitable anatomy, percutaneous closure can be considered as the first therapeutic option.

Molecular and cellular neurocardiology: development, and cellular and molecular adaptations to heart disease.

The nervous system and cardiovascular system develop in concert and are functionally interconnected in both health and disease. This white paper focuses on the cellular and molecular mechanisms that underlie neural-cardiac interactions during development, during normal physiological function in the mature system, and during pathological remodelling in cardiovascular disease. The content on each subject was contributed by experts, and we hope that this will provide a useful resource for newcomers to neurocardiology as well as aficionados.

Prognostic implications of optimal medical therapy in patients undergoing percutaneous coronary intervention for acute coronary syndrome in octogenarians.

The proportion of elderly acute coronary syndrome (ACS) patients who receive optimal medical therapy (OMT) after percutaneous coronary intervention (PCI) and whether OMT affects their long-term outcomes remain unclear. We retrospectively investigated 405 ACS patients who underwent stent implantation between 2005 and 2009, and compared the outcomes between patients <80 years of age vs. ≥80 years of age. The prescription rate of the recommended medical agents for ACS in both groups during hospitalization and 2 years after admission was also retrieved. Among the enrolled study population, 75 patients (19%) were aged ≥80 years. These elderly patients had a higher 2-year mortality compared with patients aged <80 years group. The prescription rate of beta-blockers, angiotensin-blocking drugs, and statins tended to be lower in patients aged ≥80 years than in those aged <80 years. Furthermore, among patients ≥80 years of age, those who received OMT had better clinical outcome of 2-year mortality compared to those without OMT. Elderly patients with ACS treated by PCI are at substantially higher risk of adverse events than younger patients. However, they are less likely to receive OMT. PCI with OMT might improve the clinical outcomes of elderly ACS patients.

Validation of contrast-enhanced magnetic resonance imaging to monitor regenerative efficacy after cell therapy in a porcine model of convalescent myocardial infarction.

BACKGROUND: Magnetic resonance imaging (MRI) in the CArdiosphere-Derived aUtologous stem CElls to reverse ventricUlar dySfunction (CADUCEUS) trial revealed that cardiosphere-derived cells (CDCs) decrease scar size and increase viable myocardium after myocardial infarction (MI), but MRI has not been validated as an index of regeneration after cell therapy. We tested the validity of contrast-enhanced MRI in quantifying scarred and viable myocardium after cell therapy in a porcine model of convalescent MI. METHODS AND RESULTS: Yucatan minipigs underwent induction of MI and 2-3 weeks later were randomized to receive intracoronary infusion of 12.5×10(6) mismatched allogeneic CDCs or vehicle. Allogeneic CDCs induced mild local mononuclear infiltration but no systemic immunogenicity. MRI revealed that allogeneic CDCs attenuated remodeling, improved global and regional function, decreased scar size, and increased viable myocardium compared with placebo 2 months post-treatment. Extensive histological analysis validated quantitatively the MRI measurements of scar size, scar mass, and viable mass. CDCs neither altered gadolinium contrast myocardial kinetics nor induced changes in vascular density or architecture in viable and scarred myocardium. Histology demonstrated that CDCs lead to cardiomyocyte hyperplasia in the border zone, consistent with the observed stimulation of endogenous regenerative mechanisms (cardiomyocyte cycling, upregulation of endogenous progenitors, angiogenesis). CONCLUSIONS: Contrast-enhanced MRI accurately measures scarred and viable myocardium after cell therapy in a porcine model of convalescent MI. MRI represents a useful tool for assessing dynamic changes in the infarct and monitoring regenerative efficacy.

Sema3a maintains normal heart rhythm through sympathetic innervation patterning.

Sympathetic innervation is critical for effective cardiac function. However, the developmental and regulatory mechanisms determining the density and patterning of cardiac sympathetic innervation remain unclear, as does the role of this innervation in arrhythmogenesis. Here we show that a neural chemorepellent, Sema3a, establishes cardiac sympathetic innervation patterning. Sema3a is abundantly expressed in the trabecular layer in early-stage embryos but is restricted to Purkinje fibers after birth, forming an epicardial-to-endocardial transmural sympathetic innervation patterning. Sema3a(-/-) mice lacked a cardiac sympathetic innervation gradient and exhibited stellate ganglia malformation, which led to marked sinus bradycardia due to sympathetic dysfunction. Cardiac-specific overexpression of Sema3a in transgenic mice (SemaTG) was associated with reduced sympathetic innervation and attenuation of the epicardial-to-endocardial innervation gradient. SemaTG mice demonstrated sudden death and susceptibility to ventricular tachycardia, due to catecholamine supersensitivity and prolongation of the action potential duration. We conclude that appropriate cardiac Sema3a expression is needed for sympathetic innervation patterning and is critical for heart rate control.

Coronary Artery Bypass Grafting for a Young Female Patient With Chronic Active Epstein-Barr Virus Infection.

A 24-year-old woman with chronic active Epstein-Barr virus (CAEBV) infection successfully underwent coronary artery bypass grafting for triple coronary arteries with chronic total occlusion and aneurysms. This case underscores the importance of accurate assessment and treatment of coronary artery lesions in patients with CAEBV infection.