Faculty Bibliography

The first 2 living recipients of pig hearts died unexpectedly within 2 months, despite both recipients receiving what over 30 years of nonhuman primate (NHP) research would suggest were the optimal gene edits and immunosuppression to ensure success. These results prompt us to question how faithfully data from the NHP model translate into human outcomes. Before attempting any further heart xenotransplants in living humans, it is highly advisable to gain a more comprehensive understanding of why the promising preclinical NHP data did not accurately predict outcomes in humans. It is also unlikely that additional NHP data will provide more information that would de-risk a xenoheart clinical trial because these cases were based on the best practices from the most successful NHP results to date. Although imperfect, the decedent model offers a complementary avenue to determine appropriate treatment regimens to control the human immune response to xenografts and better understand the biologic differences between humans and NHP that could lead to such starkly contrasting outcomes. Herein, we explore the potential benefits and drawbacks of the decedent model and contrast it to the advantages and disadvantages of the extensive body of data generated in the NHP xenoheart transplantation model.

BACKGROUND:infection (CDI) in patients requiring concomitant systemic antibiotics. OBJECTIVES/OBJECTIVE:To evaluate prescribing practices of vancomycin for CDI in patients that required concurrent systemic antibiotics and to determine whether a prolonged duration of vancomycin (>14 days), compared to a standard duration (10-14 days), decreased CDI recurrence. METHODS:(VRE). RESULTS:= .083) were not significantly different between groups. Discontinuation of vancomycin prior to completion of antibiotics was an independent predictor of 8-week recurrence on multivariable logistic regression (OR, 4.8; 95% CI, 1.3-18.1). CONCLUSIONS:Oral vancomycin prescribing relative to the systemic antibiotic end date may affect CDI recurrence to a greater extent than total vancomycin duration alone. Further studies are needed to confirm these findings.

Genetically modified xenografts are one of the most promising solutions to the discrepancy between the numbers of available human organs for transplantation and potential recipients. To date, a porcine heart has been implanted into only one human recipient. Here, using 10-gene-edited pigs, we transplanted porcine hearts into two brain-dead human recipients and monitored xenograft function, hemodynamics and systemic responses over the course of 66 hours. Although both xenografts demonstrated excellent cardiac function immediately after transplantation and continued to function for the duration of the study, cardiac function declined postoperatively in one case, attributed to a size mismatch between the donor pig and the recipient. For both hearts, we confirmed transgene expression and found no evidence of cellular or antibody-mediated rejection, as assessed using histology, flow cytometry and a cytotoxic crossmatch assay. Moreover, we found no evidence of zoonotic transmission from the donor pigs to the human recipients. While substantial additional work will be needed to advance this technology to human trials, these results indicate that pig-to-human heart xenotransplantation can be performed successfully without hyperacute rejection or zoonosis.

Objectives/UNASSIGNED:Proning patients with acute respiratory distress syndrome (ARDS) has been associated with increased survival, though little data exists evaluating the safety and feasibility of proning ARDS patients on extracorporeal membrane oxygenation (ECMO). Methods/UNASSIGNED:, 2020 was performed. All proning events were evaluated for complications, as well as change in compliance, sweep, oxygenation and flow. The primary outcome of this study was the rate major morbidity associated with proning while on ECMO. Results/UNASSIGNED:of 86 pre to 103 post (p<0.0001). Mean ECMO flow was unchanged. Conclusions/UNASSIGNED:Proning in patients with ARDS on ECMO is safe with an associated improvement in lung mechanics. With careful planning and coordination, these data support the practice of appropriately proning patients with severe ARDS, even if they are on ECMO.

BACKGROUND:Xenografts from genetically modified pigs have become one of the most promising solutions to the dearth of human organs available for transplantation. The challenge in this model has been hyperacute rejection. To avoid this, pigs have been bred with a knockout of the alpha-1,3-galactosyltransferase gene and with subcapsular autologous thymic tissue. METHODS:We transplanted kidneys from these genetically modified pigs into two brain-dead human recipients whose circulatory and respiratory activity was maintained on ventilators for the duration of the study. We performed serial biopsies and monitored the urine output and kinetic estimated glomerular filtration rate (eGFR) to assess renal function and xenograft rejection. RESULTS:in Recipient 2. In both recipients, the creatinine level, which had been at a steady state, decreased after implantation of the xenograft, from 1.97 to 0.82 mg per deciliter in Recipient 1 and from 1.10 to 0.57 mg per deciliter in Recipient 2. The transplanted kidneys remained pink and well-perfused, continuing to make urine throughout the study. Biopsies that were performed at 6, 24, 48, and 54 hours revealed no signs of hyperacute or antibody-mediated rejection. Hourly urine output with the xenograft was more than double the output with the native kidneys. CONCLUSIONS:Genetically modified kidney xenografts from pigs remained viable and functioning in brain-dead human recipients for 54 hours, without signs of hyperacute rejection. (Funded by Lung Biotechnology.).

INTRODUCTION: An extracorporeal membrane oxygenation (ECMO) circuit exchange is a commonly encountered procedure with potential for significant hemodynamic risks in patients with already compromised physiology. We aim to examine potential predictors and safety of circuit exchanges (CE) in COVID-19 patients receiving veno-venous (VV) ECMO support.
METHOD(S): This is a single-center, retrospective study of 29 patients with COVID-19 infection requiring VV ECMO support between March 2020 and April 2020. Pre- ECMO characteristics, complications, and blood product requirements were compared between patients with and without CE using independent two-sample Student's t-tests for continuous variables and chi-squared test for categorical variables.
RESULT(S): Overall survival to discharge was 97% (28/29). 13 patients did not require any CE and 16 patients required a total of 42 CEs. There was no difference in baseline characteristics, pre-ECMO ventilator settings, SOFA, or VIS scores between patients who required a circuit exchange versus those who did not. However, patients who required circuit exchanges had a higher lactate at time of cannulation (1.83 vs 1.32, p=0.011). The CE group had a longer duration of ECMO support (53.31 vs 13.31 days, p=0.004), higher pulmonary complications defined as hemothorax or pneumothorax (8/16 vs 0/13, p=0.003), and higher blood product transfusions including packed red blood cell (5,525 mL vs 1,261 mL, p=0.0001), cryoprecipitate (1,735 mL vs 501 mL, p=0.004), and platelet (486 mL vs 111 mL, p=0.019). In the 42 CEs, no major complications, including hemodynamic instability or cardiac arrest, occurred during the exchange.
CONCLUSION(S): Severity of underlying lung injury, ECMO duration, and pre-cannulation lactate may be markers for potential CE in COVID-19 patients requiring ECMO. They may be associated with higher blood product transfusion requirements and while CEs are procedures performed in hemodynamically tenuous patients, they are able to be performed safely

OBJECTIVES/OBJECTIVE:To assess the impact of percutaneous dilational tracheostomy in coronavirus disease 2019 patients requiring mechanical ventilation and the risk for healthcare providers. DESIGN/METHODS:Prospective cohort study; patients were enrolled between March 11, and April 29, 2020. The date of final follow-up was July 30, 2020. We used a propensity score matching approach to compare outcomes. Study outcomes were formulated before data collection and analysis. SETTING/METHODS:Critical care units at two large metropolitan hospitals in New York City. PATIENTS/METHODS:Five-hundred forty-one patients with confirmed severe coronavirus disease 2019 respiratory failure requiring mechanical ventilation. INTERVENTIONS/METHODS:Bedside percutaneous dilational tracheostomy with modified visualization and ventilation. MEASUREMENTS AND MAIN RESULTS/RESULTS:Required time for discontinuation off mechanical ventilation, total length of hospitalization, and overall patient survival. Of the 541 patients, 394 patients were eligible for a tracheostomy. One-hundred sixteen were early percutaneous dilational tracheostomies with median time of 9 days after initiation of mechanical ventilation (interquartile range, 7-12 d), whereas 89 were late percutaneous dilational tracheostomies with a median time of 19 days after initiation of mechanical ventilation (interquartile range, 16-24 d). Compared with patients with no tracheostomy, patients with an early percutaneous dilational tracheostomy had a higher probability of discontinuation from mechanical ventilation (absolute difference, 30%; p < 0.001; hazard ratio for successful discontinuation, 2.8; 95% CI, 1.34-5.84; p = 0.006) and a lower mortality (absolute difference, 34%, p < 0.001; hazard ratio for death, 0.11; 95% CI, 0.06-0.22; p < 0.001). Compared with patients with late percutaneous dilational tracheostomy, patients with early percutaneous dilational tracheostomy had higher discontinuation rates from mechanical ventilation (absolute difference 7%; p < 0.35; hazard ratio for successful discontinuation, 1.53; 95% CI, 1.01-2.3; p = 0.04) and had a shorter median duration of mechanical ventilation in survivors (absolute difference, -15 d; p < 0.001). None of the healthcare providers who performed all the percutaneous dilational tracheostomies procedures had clinical symptoms or any positive laboratory test for severe acute respiratory syndrome coronavirus 2 infection. CONCLUSIONS:In coronavirus disease 2019 patients on mechanical ventilation, an early modified percutaneous dilational tracheostomy was safe for patients and healthcare providers and associated with improved clinical outcomes.