Faculty Bibliography

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.

Background/UNASSIGNED:The hemodynamic effects of pre-transplant vaccination against COVID-19 among heart transplant candidates hospitalized for advanced heart failure remains unknown. Methods/UNASSIGNED:A retrospective chart review was conducted at a high-volume transplant center from January through December 2021. 22 COVID-19 vaccination events occurred among patients hospitalized for decompensated heart failure while awaiting transplantation. Primary outcomes included inotrope and vasopressor dosages. Secondary outcomes included vital signs, pulmonary artery catheter measurements, diuretic dosages, and renal function. Data were extracted 24 h before through 72 h after vaccination. Results/UNASSIGNED:One of 22 vaccination events was associated with hemodynamic changes requiring increased inotropic and vasopressor support post-vaccination. In all other cases, transient hemodynamic changes occurred without need for escalated therapy. Conclusions/UNASSIGNED:COVID-19 vaccination can be administered safely to most critically ill patients with advanced heart failure including those awaiting transplantation. All patients should be monitored closely as some may be susceptible to significant hemodynamic changes.

Purpose: The American Society of Transplantation and the International Society of Heart and Lung Transplantation recommend COVID-19 vaccination of transplant candidates to maximize immunity, as vaccination after initiation of immunosuppression may confer only partial immunity. However, there are concerns about the impact of vaccine-induced systemic inflammatory responses in critically ill patients with variable hemodynamic states. We aim to explore the safety of pre-transplant vaccination by examining the immediate impact of COVID-19 vaccination on the hemodynamics of hospitalized patients awaiting transplant.
Method(s): A retrospective chart review at a major transplant center was conducted among all heart transplant recipients from January 2021 through September 2021 who were hospitalized and listed or under consideration for listing for transplant at the time of COVID-19 vaccination. Primary outcomes included vital signs, hemodynamic parameters from pulmonary artery catheter-derived measurements, and changes in inotrope/vasopressor infusion rates. Data were extracted at fixed time points 24 hours before and up to 72 hours after vaccination. Given the small sample size and exploratory study nature, only univariate analysis was performed.
Result(s): Of the 50 patients who received heart transplants at our center from January 2021 through September 2021, 37 patients were vaccinated against COVID-19. 13 of those patients were vaccinated before transplant while hospitalized, and 10 of those 13 patients had a pulmonary artery catheter in place at the time of immunization. No significant changes in vital signs (blood pressure, heart rate), hemodynamics (cardiac index, pulmonary artery pressures, systemic vascular resistance), or vasopressor/inotrope infusion rates were observed after vaccination.
Conclusion(s): In this exploratory review of COVID-19 vaccination in heart transplant candidates, we did not detect any notable changes to hemodynamics in the first 72 hours after immunization. Although further investigative research is needed to assess COVID-19 vaccine safety comprehensively in patients with advanced heart failure, the absence of notable hemodynamic changes in this cohort of heart transplant candidates encourages the continued use of COVID-19 vaccination among hospitalized patients with advanced heart failure who are awaiting transplant.
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A 12-year-old girl with severe acute respiratory syndrome coronavirus 2 infection presented as phlegmasia cerulea dolens with venous gangrene. Emergent mechanical thrombectomy was complicated by a massive pulmonary embolism and cardiac arrest, for which extracorporeal cardiopulmonary resuscitation and therapeutic hypothermia were used. Staged ultrasound-assisted catheter-directed thrombolysis was used for treatment of bilateral pulmonary emboli and the extensive lower extremity deep vein thrombosis while the patient received extracorporeal membrane oxygenation support. We highlight the need for heightened suspicion for occult severe acute respiratory syndrome coronavirus 2 infection among children presenting with unusual thrombotic complications.

Background /UNASSIGNED:Acute severe mitral regurgitation (MR) associated with cardiogenic shock is a life-threatening emergency. Traditional teaching has focused on the need for emergent coronary angiography and/or intra-aortic balloon counterpulsation in preparation for emergent open-heart surgery for repair/replacement. Unfortunately, emergent open-heart surgery in patients with acute MR complicated by cardiogenic shock is associated with 25-46% perioperative mortality. New devices have provided additional options for stabilization prior to emergent surgery which facilitate improved outcomes. Case summary /UNASSIGNED:mechanical circulatory support with an oxygenator spliced into the circuit, akin to veno-arterial extracorporeal membrane oxygenation (ECMO), facilitated haemodynamic stabilization and decongestion of the lungs facilitating successful bridge to mitral valve surgery. Successful discharge to home was achieved in both patients with good neurological outcomes and sustained long-term functional recovery at 18 and 14 months, respectively. Discussion/UNASSIGNED:, with or without ECMO, facilitates management of the critically ill cardiogenic shock patient with acute severe MR.