Multidirectional Filamented Light Biofabrication Creates Aligned and Contractile Cardiac Tissues.

Biofabricating 3D cardiac tissues that mimic the native myocardial tissue is a pivotal challenge in tissue engineering. In this study, we fabricate 3D cardiac tissues with controlled, multidirectional cellular alignment and directed or twisting contractility. We show that multidirectional filamented light can be used to biofabricate high-density (up to 60 × 106 cells mL-1) tissues, with directed uniaxial contractility (3.8x) and improved cell-to-cell connectivity (1.6x gap junction expression). Furthermore, by using multidirectional light projection, we can partially overcome cell-induced light attenuation, and fabricate larger tissues with multidirectional cellular alignment. For example, we fabricate a tri-layered myocardium-like tissue and a bi-layered tissue with torsional contractility. The approach provides a new strategy to rapidly fabricate aligned cardiac tissues relevant to regenerative medicine and biohybrid robotics.

Repurposing of glatiramer acetate to treat cardiac ischemia in rodent models.

Myocardial injury may ultimately lead to adverse ventricular remodeling and development of heart failure (HF), which is a major cause of morbidity and mortality worldwide. Given the slow pace and substantial costs of developing new therapeutics, drug repurposing is an attractive alternative. Studies of many organs, including the heart, highlight the importance of the immune system in modulating injury and repair outcomes. Glatiramer acetate (GA) is an immunomodulatory drug prescribed for patients with multiple sclerosis. Here, we report that short-term GA treatment improves cardiac function and reduces scar area in a mouse model of acute myocardial infarction and a rat model of ischemic HF. We provide mechanistic evidence indicating that, in addition to its immunomodulatory functions, GA exerts beneficial pleiotropic effects, including cardiomyocyte protection and enhanced angiogenesis. Overall, these findings highlight the potential repurposing of GA as a future therapy for a myriad of heart diseases.

Volume-Outcome Relationship of Resternotomy Coronary Artery Bypass Grafting.

BACKGROUND: We assessed volume-outcome relationships of resternotomy coronary artery bypass grafting (CABG). METHODS: We studied 1,362,218 first-time CABG and 93,985 resternotomy CABG patients reported to The Society of Thoracic Surgeons Adult Cardiac Surgery Database between 2010 and 2019. Primary outcomes were in-hospital mortality and mortality and morbidity (M&M) rates calculated per hospital and per surgeon. Outcomes were compared across 6 total cardiac surgery volume categories. Multivariable generalized linear mixed-effects models were used considering continuous case volume as the main exposure, adjusting for patient characteristics and within-surgeon and hospital variation. RESULTS: We observed a decline in resternotomy CABG unadjusted mortality and M&M from the lowest to the highest case-volume categories (hospital-level mortality, 3.9% ± 0.6% to 3.3% ± 0.1%; M&M, 18.5% ± 1.1% to 15.7% ± 0.4%, P < .001; surgeon-level mortality, 4.1% ± 0.3% to 4.1% ± 1.3%; M&M, 18.5% ± 0.6% to 14.5% ± 2.2%, P < .001). Looking at outcomes vs continuous volume showed that beyond a minimum annual volume (hospital 200-300 cases; surgeon 100-150 cases, approximately), mortality and M&M rates did not further improve. Using individual-level data and adjusting for patient characteristics and clustering within surgeon and hospital, we found higher procedural volume was associated with improved surgeon-level outcomes (mortality adjusted odds ratio, 0.39/100 procedures; 95% CI, 0.24-0.61; M&M adjusted odds ratio, 0.37/100 procedures; 95% CI, 0.28-0.48; P < .001 for both). Hospital-level adjusted volume-outcomes associations were not statistically significant. CONCLUSIONS: We observed an inverse relationship between total cardiac case volume and resternotomy CABG outcomes at the surgeon level only, indicating that individual surgeon's experience, rather than institutional volume, is the key determinant.

Resternotomy Coronary Artery Bypass 1999-2018: Insights From The Society of Thoracic Surgeons Adult Cardiac Surgery Database.

BACKGROUND: We sought to quantify the risk trend of resternotomy coronary artery bypass grafting (CABG) over the past 2 decades. METHODS: We compared the outcomes of 194 804 consecutive resternotomy CABG patients and 1 445 894 randomly selected first-time CABG patients (50% of total) reported to The Society of Thoracic Surgeons Adult Cardiac Surgery Database between 1999 and 2018. Primary outcomes were in-hospital mortality and overall morbidity. Using multiple logistic regression for each outcome for each year, we computed the annual trends of risk-adjusted odds ratios for the primary outcomes in the entire cohort and in 194 776 propensity-matched pairs. RESULTS: The annual resternotomy CABG case volume from participating centers declined by 68%, from a median of 25 (range, 14-44) to a median of 8 (range, 4-15). Compared with first-time CABG, resternotomy CABG patients were consistently older, with higher proportions of comorbidities. After propensity matching, primary outcomes of resternotomy and first-time CABG were similar (mortality: 3.5% vs 2.3%, standardized difference [SDiff], 7.5%; morbidity: 40.7% vs 40.3%, SDiff, 0.9%). Mortality of resternotomy CABG performed after prior CABG was higher than that after prior non-CABG (4.3% vs 2.4%; SDiff, 10.8). Morbidity was similar between these subgroups (41.0% vs 39.1%; SDiff, 2.9). The adjusted odds ratio for mortality after resternotomy CABG declined from 1.93 (95% CI, 1.73-2.16) to 1.22 (95% CI, 0.92-1.62), and that of morbidity declined from 1.13 (95% CI, 1.08-1.18) to 0.91 (95% CI, 0.87-0.95), P < .001 for both. CONCLUSIONS: The risk of resternotomy CABG has decreased substantially over time. Resternotomy CABG performed after a prior CABG is higher risk compared with that performed after a non-CABG operation.

Right-Sided Cardiac Calcifying Fibrous Pseudotumor Manifesting With Embolic Stroke.

This report describes the case of a 43-year-old woman with a right-sided cardiac calcifying fibrous pseudotumor who presented with embolic stroke. This rare clinicopathologic entity should be included in the differential diagnosis of cardiac masses. Tissue diagnosis should be pursued. Management should be tailored to symptoms and feasibility of resection.

Endovascular brachytherapy for extensive right-heart and pulmonary artery sarcoma - a case report.

PURPOSE: Primary sarcoma of the heart is a rare but devastating tumor. Median survival with conventional treatment is 8-12 months. When resection is not feasible, patients often succumb to heart failure secondary to obstruction of blood flow, valve dysfunction, chamber compression or conduction abnormalities. Palliative treatment options include systemic chemotherapy and external beam irradiation. We herein describe a novel technique using endovascular brachytherapy, aiming at reducing tumor mass, alleviating right ventricular pressure overload and at the same time keeping the option of R0 resection viable. MATERIAL AND METHODS: A 35-year-old man was diagnosed with a non-resectable high-grade intimal sarcoma of the right ventricle (RV), main pulmonary artery (PA) and right PA. After three cycles of doxorubicin and ifosfamide, the patient's symptoms of right heart failure worsened. Imaging documented tumor progression and supra-systemic pulmonary artery pressure. Through a trans-femoral venous access, a brachytherapy sleeve was placed in the RV and main and right PA. A dose of 20 Gy was delivered over a period of ten minutes. RESULTS: The patient had an uneventful course and was discharged home 24 hours after the procedure. Ten months after brachytherapy, repeat imaging demonstrated a significant reduction in tumor volume and an increase in pulmonary artery cross-sectional area with a marked reduction of pulmonary artery pressure, leading to a complete resolution of heart failure symptoms. CONCLUSIONS: Endovascular brachytherapy is a novel, safe and effective therapeutic modality for non-resectable primary cardiac sarcomas either for palliation of obstruction, or tumor mass reduction to allow complete resection.

Expression and activation of toll-like receptor 3 and toll-like receptor 4 on human corneal epithelial and conjunctival fibroblasts.

BACKGROUND: Toll-like receptors (TLRs) are recognized as important contributors to the initiation and modulation of the inflammatory response in the eye. This study investigated the precise expression patterns and functionality of TLRs in human corneal epithelial cells (HCE) and in conjunctival fibroblasts (HCF). METHODS: The cell surface expression of TLRs 2-4, TLR7 and TLR9 in HCE and HCF was examined by flow cytometry with or without stimulation with lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (poly I:C). The mRNA expression of the TLRs was determined by real-time PCR. The protein content levels of interleukin (IL)-6, IL-8, IL-1ß and tumor necrosis factor-α (TNF-α) were measured in HCE and HCF using multiplex fluorescent bead immunoassay (FBI). RESULTS: The surface expression of TLR3 and TLR4 was detected on both HCE and HCF. Following incubation with LPS, the percentage of HCE cells staining for TLR4 decreased from 10.18% to 0.62% (P < 0.001). Incubation with poly I:C lowered the percentage of HCE cells positive for TLR3 from 10.44% to 2.84% (P < 0.001). The mRNA expression of TLRs2, 4, 7 and 9 was detected in HCE only. Activation of HCE with LPS complex elicited protein secretion up to 4.51 ± 0.85-fold higher levels of IL-6 (P < 0.05), 2.5 ± 0.36-fold IL-8 (P > 0.05), 4.35 ± 1.12-fold IL-1ß (P > 0.05) and 29.35 ± 2.3-fold TNFα (P < 0.05) compared to cells incubated in medium. CONCLUSIONS: HCF and HCE both express TLRs that respond to specific ligands by increasing cytokine expression. Following activation, the surface expression of TLR3 and TLR4 on HCE is decreased, thus creating a negative feedback loop, mitigating the effect of TLR activation.