Therapeutic potential of human induced pluripotent stem cell-derived cardiac tissue in an ischemic model with unloaded condition mimicking left ventricular assist device.

OBJECTIVE: This study aimed to explore the therapeutic potential of human induced pluripotent stem cell (hiPSC)-derived cardiac tissues (HiCTs) in the emerging approach of bridge to recovery for severe heart failure with ventricular assist devices. We used a rat model of heterotopic heart transplantation (HTx) to mimic ventricular assist device support and heart unloading. METHODS: HiCTs were created by inserting gelatin hydrogel microspheres between cell sheets made from hiPSC-derived cardiovascular cells. Male athymic nude rats underwent myocardial infarction (MI) and were divided into the following groups: MI (loaded, untreated control), MI + HTx (unloaded, untreated control), MI + HTx + HiCT (unloaded, treated), and MI + HiCT (loaded, treated). HiCTs were placed on the epicardium of the heart in treated groups. We evaluated HiCT engraftment, fibrosis, and neovascularization using histologic analysis. RESULTS: After 4 weeks, HiCTs successfully engrafted in 5 of 6 rats in the MI + HTx + HiCT group (83.3%). The engrafted HiCT area was greater under unloaded conditions (MI + HTx + HiCT) than loaded conditions (MI + HiCT) (P < .05). MI + HTx + HiCT had a significantly smaller infarct area compared with MI and MI + HTx. The MI + HTx + MiCT group exhibited greater vascular density in the border zone than MI and MI + HTx. HiCT treatment suppressed cardiomyocyte atrophy due to left ventricular unloading (P = .001). The protein level of muscle-specific RING finger 1, an atrophy-related ubiquitin ligase, was lower in the MI + HTx + HiCT group than in MI + HTx (P = .036). CONCLUSIONS: Transplanting HiCTs into ischemic hearts under unloaded conditions promoted engraftment, neovascularization, attenuated infarct remodeling, and suppressed myocyte atrophy. These results suggest that HiCT treatment could contribute to future advancements in bridge to recovery.

[Neuroendovascular Treatment for Cerebral Embolism in a Patient just after Aortic Valve Replacement；Report of a Case].

A 67-year-old woman suffered from severe aortic stenosis and atrial fibrillation, and underwent aortic valve replacement with a St. Jude Medical Regent 23-mm valve and pulmonary vein isolation using an AtriCure Isolator Synergy.At 6 days after the operation, she experienced sudden onset of atrial fibrillation, left side paralysis, and dysarthria. Right internal carotid artery embolism was diagnosed via magnetic resonance imaging, and we promptly performed neuroendovascular therapy with a Solitaire FR. Neuroendovascular treatment succeeded, and her neurological function was restored to near-normal. Her post-treatment course was uneventful, and she is currently well without neurological dysfunction.

Truncus arteriosus communis with interrupted aortic arch: successful repair using a novel technique.

We report a successful one-stage biventricular repair of truncus arteriosus communis with interrupted aortic arch in a neonate. This newborn girl was diagnosed with truncus arteriosus communis type III-B (Congenital Heart Surgeons Society classification) by the echocardiography and three-dimensional computed tomography. We present a new reconstructive approach for such heart defects, involving a modified Lecompte maneuver combined with arch reconstruction, by suturing the ascending aorta to the descending aorta in end-to-end fashion called the swing-back technique.

Successful surgical treatment of intravascular ultrasonography catheter entrapment.

Coronary angiography (CAG) was performed in a 77-year-old woman who presented with chest discomfort. The CAG showed two diseased vessels. For treatment, the patient underwent angioplasty and stenting. During intravascular ultrasonography (IVUS) following stent deployment, the IVUS catheter became entrapped in the left anterior descending coronary artery, causing ischemic changes in the anterolateral wall, which were apparent on the electrocardiogram. The patient underwent emergency coronary artery bypass grafting and removal of the entrapped IVUS catheter.

[Successful resection of left ventricular myxoma in a toddler; report of a case].

A 4-year-old girl was found to have large left ventricular myxoma without any tumor-related symptoms. She underwent an urgent surgery and the myxoma was successfully removed through a left ventriculectomy. Great care was taken to prevent tumor-embolization during surgery, and to resect the endocardium attaching directly to the tumor. Future surveillance of this case warrants our operative technique described in this report.