Faculty Bibliography

BACKGROUND:Severe coronavirus disease 2019 (COVID-19) can cause acute respiratory failure requiring mechanical ventilation. Venovenous (VV) extracorporeal membrane oxygenation (ECMO) has been used in patients in whom conventional mechanical ventilatory support has failed. To date, published data have focused on survival from ECMO and survival to discharge. In addition to survival to discharge, this study reports 1-year follow-up data for patients who were successfully discharged from the hospital. METHODS:A single-institution, retrospective review of all patients with severe COVID-19 who were cannulated for VV-ECMO between March 10, 2020 and May 1, 2020 was performed. A multidisciplinary ECMO team evaluated, selected, and managed patients with ECMO support. The primary outcome of this study was survival to discharge. Available 1-year follow-up data are also reported. RESULTS:A total of 30 patients were supported with VV-ECMO, and 27 patients (90%) survived to discharge. All patients were discharged home or to acute rehabilitation on room air, except for 1 patient (3.7%), who required supplemental oxygen therapy. At a median follow-up of 10.8 months (interquartile range [IQR], 8.9-14.4 months) since ECMO cannulation, survival was 86.7%, including 1 patient who underwent lung transplantation. Of the patients discharged from the hospital, 44.4% (12/27) had pulmonary function testing, with a median percent predicted forced expiratory volume of 100% (IQR, 91%-110%). For survivors, a 6-minute walk test was performed in 59.3% (16/27), with a median value of 350 m (IQR, 286-379 m). CONCLUSIONS:A well-defined patient selection and management strategy of VV-ECMO support in patients with severe COVID-19 resulted in exceptional survival to discharge that was sustained at 1-year after ECMO cannulation.

BACKGROUND:Specific aetiologies of cardiomyopathy can significantly impact treatment options as well as appropriateness and prioritisation for advanced heart failure therapies such as ventricular assist device (VAD) or orthotopic heart transplantation (OHT). We reviewed the tissue diagnoses of patients who underwent advanced therapies for heart failure (HF) to identify diagnostic discrepancies. METHODS:This study presents a retrospective cohort of the aetiology of cardiomyopathy in 118 patients receiving either durable VAD or OHT. Discrepancies between the preoperative aetiological diagnosis of cardiomyopathy with the pathological diagnosis were recorded. Echocardiographic and haemodynamic data were reviewed to examine differences in patients with differing aetiological diagnoses. RESULTS:Twelve (12) of 118 (12/118) (10.2%) had a pathological diagnosis that was discordant with pre-surgical diagnosis. The most common missed diagnoses were infiltrative cardiomyopathy (5) and hypertrophic cardiomyopathy (3). Patients with misidentified aetiology of cardiomyopathy had smaller left ventricular (LV) dimensions on echocardiography than patients with dilated cardiomyopathy (5.8±0.9 vs 6.7±1.1 respectively p=0.01). CONCLUSIONS:Most HF patients undergoing VAD and OHT had a correct diagnosis for their heart failure prior to treatment, but a missed diagnosis at time of intervention (VAD or OHT) was not uncommon. Smaller LV dimension on echocardiogram in a patient with a non-ischaemic cardiomyopathy warrants further workup for a more specific aetiology.

This paper responds to the position statement released by the American College of Physicians (ACP) entitled "Ethics, Determination of Death, and Organ Transplantation in Normothermic Regional Perfusion (NRP) with Controlled Donation after Circulatory Determination of Death (cDCD): American College of Physicians Statement of Concern." The ACP's statement engages with critical ethical issues surrounding cDCD NRP, but several of their conclusions are flawed. Contrary to the statement, the practice respects the dead donor rule and the legal definition of death while honoring the wishes of the deceased and their loved ones to help save the lives of those in need of organ transplants. cDCD NRP is well established in many countries, it can enhance trust in medical practice and organ donation, and will increase the availability of optimal organs for life-saving transplants.

BACKGROUND:The VentriFlo® True Pulse Pump (VentriFlo, Inc., Pelham, NH, USA) is a new pulsatile blood pump intended for use during short-term circulatory support. The purpose of this study was to evaluate the feasibility of the VentriFlo and compare it to a conventional centrifugal pump (ROTAFLOW, Getinge, Gothenberg, Sweden) in acute pig experiments. METHODS:Pigs (40-45 kg) were supported by cardiopulmonary bypass (CPB) with the VentriFlo (n=9) or ROTAFLOW (n=5) for 6 hours. Both VentriFlo and ROTAFLOW circuits utilized standard CPB components. We evaluated hemodynamics, blood chemistry, gas analysis, plasma hemoglobin, and microcirculation at the groin skin with computer-assisted video microscopy (Optilia, Sollentuna, Sweden). RESULTS:Pigs were successfully supported by CPB for 6 hours without any pump-related complications in either group. The VentriFlo delivered an average stroke volume of 29.2 ± 4.8 mL. VentriFlo delivered significantly higher pulse pressure (29.1 ± 7.2 mm Hg vs 4.4 ± 7.0 mm Hg, p<0.01) as measured in the carotid artery, with mean aortic pressure and pump flow comparable with those in ROTAFLOW. In blood gas analysis, arterial pH was significantly lower after five hours support in the VentriFlo group (7.30 ± 0.07 vs 7.43 ± 0.03, p=0.001). There was no significant difference in plasma hemoglobin level in both groups after six hours of CPB support. In microcirculatory assessment, VentriFlo tended to keep normal capillary flow, but it was not statistically significant. CONCLUSIONS:VentriFlo-supported pigs showed comparable hemodynamic parameters with significantly higher pulse pressure compared to ROTAFLOW without hemolysis.

OBJECTIVE:This pilot study sought to evaluate the feasibility of our donation after circulatory death (DCD) heart transplantation protocol using cardiopulmonary bypass (CPB) for normothermic regional reperfusion (NRP). METHODS:Suitable local DCD candidates were transferred to our institution. Life support was withdrawn in the operating room (OR). On declaration of circulatory death, sternotomy was performed, and the aortic arch vessels were ligated. CPB was initiated with left ventricular venting. The heart was reperfused, with correction of any metabolic abnormalities. CPB was weaned, and cardiac function was assessed at 30-minute intervals. If accepted, the heart was procured with cold preservation and transplanted into recipients in a nearby OR. RESULTS:Between January 2020 and January 2021, a total of 8 DCD heart transplants were performed: 6 isolated hearts, 1 heart-lung, and 1 combined heart and kidney. All donor hearts were successfully resuscitated and weaned from CPB without inotropic support. Average lactate and potassium levels decreased from 9.39 ± 1.47 mmol/L to 7.20 ± 0.13 mmol/L and 7.49 ± 1.32 mmol/L to 4.36 ± 0.67 mmol/L, respectively. Post-transplantation, the heart-lung transplant recipient required venoarterial extracorporeal membrane oxygenation for primary lung graft dysfunction but was decannulated on postoperative day 3 and recovered uneventfully. All other recipients required minimal inotropic support without mechanical circulatory support. Survival was 100% with a median follow-up of 304 days (interquartile range, 105-371 days). CONCLUSIONS:DCD heart transplantation outcomes have been excellent. Our DCD protocol is adoptable for more widespread use and will increase donor heart availability in the United States.

Purpose: During the COVID 19- pandemic, there is no consensus on management strategies for treating infected heart transplant patients. The outcomes of these patients vary by institution. We report our center experience and management strategies to date.
Method(s): All patients who received heart transplantation, from January 4th 2018 to September 25th 2020 and were diagnosed with SARS-CoV-2 were included and full chart review was performed.
Result(s): There were 113 heart transplants at our institution by September 2020. A total of 13 (12%) patients were infected with SARS-CoV-2: 9 (69%) isolated heart, 3 heart -kidney (23%) and 1 heat- lung (8%). The median (IQR) time from transplant to diagnosis was 10 (5-16) months. The mean age was 57 years and 50% were male; 50% were of Hispanic ethnicity. The main presenting symptoms were fever (43%), cough (86%) and SOB (43%). Chest x-ray was abnormal in all patients. We evaluated all patients and 79% were hospitalized and 21% were closely monitored as outpatients. None of our patients were hospitalized at outside institutions. Two (14%) required intubation and none required V-V ECMO support. The immunotherapy was modified in all patients: MMF and prednisone were discontinued, tacrolimus dose was reduced. COVID19 treatment was: 71% received hydroxychloroquine, 50% azithromycin, 15% remdesevir, 7% convalescent plasma. All hospitalized patients received anticoagulation. One patient had 2R/3A rejection within 30 days prior to diagnosis. Graft function was maintained in all patients with median LVEF% 65 (59-65%) except one patient who had received thymoglobulin 2 weeks prior to COVID 19 infection (LVEF 30%). The patient had a prolonged intubation but ultimately recovered and was discharged from the hospital. The one death (7.1%) was a heart - kidney recipient who concomitantly presented with pseudomonas sepsis and severe neutropenia. The remaining patients have all been discharged home.
Conclusion(s): We present our single center experience in managing COVID 19 infected heart transplant patients. We implemented uniform management strategies by incorporating aggressive reduction of immunosuppression, frequent scheduled contacts with infected outpatients and making sure all infected patients requiring hospitalization were treated at a transplant center.
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Introduction: CytoSorb is a cytokine adsorption device that received FDA Emergency Use Authorization (EUA) for use in critically ill COVID-19 patients. The CTC Registry was established to collect patient-level data from U.S. centers using CytoSorb under the EUA.
Method(s): Consecutive patients on ECMO treated with CytoSorb were included. Retrospective data collection included demographics, comorbidities, COVID-19 medications, inflammatory biomarkers, and details on ECMO and CytoSorb use. Study follow-up was to hospital death or discharge. Primary outcome was ICU mortality. Comparisons between survivors and non-survivors were performed to evaluate predictors of mortality. Up-to-date information from the international Extracorporeal Life Support Organization (ELSO) ECMO COVID-19 Registry was considered to help contextualize the results.
Result(s): Fifty-two ECMO patients treated under EUA from April 2020 to April 2021 were enrolled from 5 U.S. centers. Baseline characteristics were comparable to the ELSO Registry except for higher rates of obesity in the CTC cohort. ICU mortality rates in the CTC cohort were 17.3% at 30 days, 26.9% at 90 days, and 30.8% overall. Gender, age, baseline SOFA, baseline D-dimer levels, and CytoSorb use between survivors and non-survivors are shown in the Table. Regression analyses suggested a borderline association between baseline D-dimer levels and mortality, with 32% increase in the risk of death per 1 mug/ ml increase (p = 0.055). CytoSorb was generally well tolerated without any unanticipated device-related adverse events reported.
Conclusion(s): Combined use of ECMO and CytoSorb in critically ill COVID-19 patients was associated with mortality rates that compared favorably to international benchmarks. Elevated baseline D-dimer levels appeared to be associated with increased risk of mortality