Faculty Bibliography

Controlled heart donation after circulatory determination of death (cDCD) is well-established internationally with good outcomes and could be adopted in the United States to increase heart supply if ethical and logistical challenges are comprehensively addressed. The most effective and resource-efficient method for mitigating warm ischemia after circulatory arrest is normothermic regional perfusion (NRP) in situ. This strategy requires restarting circulation after declaration of death according to circulatory criteria, which appears to challenge the legal circulatory death definition requiring irreversible cessation. Permanent cessation for life-saving efforts must be achieved to assuage this concern and ligating principal vessels maintains no blood flow to the brain, which ensures natural progression to cessation of brain function. This practice - standard in some countries - raises unique concerns about prioritizing life-saving efforts, informed authorization from decision-makers, and the clinician's role in the patient's death. To preserve public trust, medical integrity, and respect for the donor, the donation conversation must not take place until after an un-coerced decision to withdraw life-sustaining treatment made in accordance with the patient's treatment goals. The decision maker(s) must understand cDCD procedure well enough to provide genuine authorization and the preservation/procurement teams must be kept separate from the clinical care team.

Mechanical blood-immersed bearings have been used in many continuous-flow rotary blood pumps to reduce friction between relatively moving parts, but their use has been associated with a significant incidence of pump thrombosis. As newer cardiac assist devices with more advanced bearings become available, the rate of pump thrombosis will likely decrease. Nevertheless, it is important to understand the design limitations of mechanical bearings as pumps utilizing them are still in use as chronic support devices and especially in the acute setting for temporary support devices. A properly designed journal bearing should support the spinning rotor with no surface-to-surface contact between the bearing and journal surfaces. The journal continuously undergoes orbital motion within the bearing, which can be "stable" or "unstable." Unstable orbital motion causes the journal to move progressively off-center until it collides with the bearing, and even minor variations in manufacturing can create off-design operation and dynamic instability of the journal. Since blood is the lubricant in most clinically-used rotary blood pumps, lubricant viscosity can vary abruptly in response to changes in hematocrit or plasma protein concentration. Additionally, shear stress from the high-speed rotor can cause hemolysis and plasma protein denaturation. We reviewed theoretical design and operating principles of mechanical bearings and discuss why the phenomenon of mechanical bearing thrombosis may be an inherent design issue dependent on variables that are beyond the control of clinicians.

Introduction: Our institution's Adult ECMO Program started in 2015 and continues to see exponential growth with an average of 89% annual increase in volume. When demand for ECMO exceeds available resources, the multiple teams, resources and processes involved in the care of these patients are challenged to provide excellent outcomes. Our program made specific changes to accommodate increased volume while maintaining quality. Our growth directly impacted staff exposure and expertise, locations of ECMO care, emergent bedside cannulations, and utilization of equipment and supplies.
Result(s): Our team coordinated comprehensive training courses to increase the number of ECMO-credentialed physicians and advanced practice providers. We then focused on improving bedside cannulations. We provided cannulation didactic and simulation training for a cohort of critical care nurses, created a single ECMO Perfusion activation number, and increased available primed circuits. We also rebuilt our cannulation carts, using an exchange process for immediate replenishment of supplies. All carts were streamlined to one lay out and were expanded across the hospital in five different locations. We increased our equipment inventory from 9 to 15 consoles and introduced a more cost-effective ECMO system. Last, we implemented ECMO safety rounds, a biweekly bedside audit of existing safety measures that also allowed for real-time staff education.
Conclusion(s): Our patient outcomes continue to meet the national ELSO benchmarks for survival rates. As our growth continues, all areas require ongoing assessment and evaluation to maintain best practices. With proper planning and resources, quality patient outcomes can be maintained

OBJECTIVES/OBJECTIVE:Patients with low left ventricular ejection fraction (LVEF) undergoing high-risk coronary artery bypass grafting (CABG) are at increased risk for postcardiotomy cardiogenic shock. This report describes planned concomitant microaxial temporary mechanical support (MA-TMS) device placement as a viable bridge-to-recovery strategy for high-risk patients receiving surgical revascularization. METHODS:A retrospective review was performed for all patients from October 2017 to May 2019 with low LVEF (<30%), New York Heart Association Class III or IV symptoms, and myocardial viability who underwent CABG with prophylactic MA-TMS support at a single institution (n = 13). RESULTS:Mean patient age was 64.8 years, and 12 patients (92%) were male. Eight patients (62%) presented with acute coronary syndrome. Mean predicted risk of mortality was 4.6%, ranging from 0.6% to 15.6%. An average of 3.4 grafts were performed per patient. Greater than 60% of patients were extubated within 48 hours and out-of-bed within 72 hours, and the average duration of MA-TMS was 5.7 days. Mean postoperative length of stay was 16.7 days. There were no postoperative myocardial infarctions or deaths. CONCLUSIONS:Prophylactic MA-TMS may allow safe and effective surgical revascularization for patients with severe left ventricular dysfunction who may otherwise be offered a durable ventricular assist device.

Purpose: In October 2018, a new US adult heart allocation scheme was enacted in which the etiology of cardiomyopathy can play a significant role in the prioritization of patients listed for transplantation. Given this, we embarked on a review of the diagnoses of patients who underwent therapy for advanced heart failure at our center.
Method(s): We retrospectively reviewed the etiology of cardiomyopathy of patients receiving either durable ventricular assist device (VAD) or orthotopic heart transplantation (OHT) at NYU Langone Medical Center in New York, NY between January 2011 and October 2018. We evaluated for discrepancies between the primary HF diagnosis at time of operation with the ultimate diagnosis, combining both clinical follow-up data and cardiac pathology.
Result(s): During the study period, a total of 110 patients were treated with advanced therapies, of which the majority (74.5%) were male. 40.9% were African American, 35.4% Caucasian, 4.5% Asian, and 23.6% Hispanic. 86.3% underwent VAD and 22.0% underwent OHT. The average age of those undergoing OHT and VAD were 58 and 61 respectively. The most common reported etiology of HF was dilated cardiomyopathy (57.3%), followed by ischemic (36.3%), familial DCM (1.8%), amyloidosis (1.8%), restrictive cardiomyopathy (1.8%), and sarcoidosis (0.9%). On final review of the diagnoses in these patients, 14 (12.7%) had a final diagnosis that was inconsistent with the prior reported one. 5 were clerical errors, but 9 were significant deviations from the prior diagnosis. The most common diagnoses that were misidentified prior to VAD or OHT were cardiac sarcoidosis (2), cardiac amyloidosis (2), and hypertrophic cardiomyopathy (2). Among those 9 patients, 7 patients received VAD with 5 eventually requiring OHT (median days to OHT = 248); 2 patients directly received OHT. All of those are alive except one patient who was lost to follow-up (transferred care to another center). Patients in whom the diagnosis was misidentified prior to VAD or OHT had smaller LV dimensions on transthoracic echocardiography on average than other LVAD or OHT patients with non-ischemic cardiomyopathy.
Conclusion(s): In this single-center review, we found that the majority of HF patients undergoing VAD and OHT had a correct diagnosis for their heart failure prior to treatment, although notably 8.1% had a missed diagnosis at time of intervention (VAD or OHT). Appropriately identifying the subtype of cardiomyopathy remains challenging especially in advanced HF patients but can significantly impact waiting list time in the current organ allocation scheme. A normal or minimally increased LV dimension on echocardiogram in a patient with advanced non-ischemic cardiomyopathy may warrant further workup for another diagnosis.
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AIMS/OBJECTIVE:The risk of HeartMate II (HMII) left ventricular assist device (LVAD) thrombosis has been reported, and serum lactate dehydrogenase (LDH), a biomarker of haemolysis, increases secondary to LVAD thrombosis. This study evaluated longitudinal measurements of LDH post-LVAD implantation, hypothesizing that LDH trends could timely predict future LVAD thrombosis. METHODS AND RESULTS/RESULTS:From October 2004 to October 2014, 350 HMIIs were implanted in 323 patients at Cleveland Clinic. Of these, patients on 339 HMIIs had at least one post-implant LDH value (7996 total measurements). A two-step joint model combining longitudinal biomarker data and pump thrombosis events was generated to assess the effect of changing LDH on thrombosis risk. Device-specific LDH trends were first smoothed using multivariate boosted trees, and then used as a time-varying covariate function in a multiphase hazard model to analyse time to thrombosis. Pre-implant variables associated with time-varying LDH values post-implant using boostmtree were also investigated. Standardized variable importance for each variable was estimated as the difference between model-based prediction error of LDH when the variable was randomly permuted and prediction error without permuting the values. The larger this difference, the more important a variable is for predicting the trajectory of post-implant LDH. Thirty-five HMIIs (10%) had either confirmed (18) or suspected (17) thrombosis, with 15 (43%) occurring within 3 months of implant. LDH was associated with thrombosis occurring both early and late after implant (P < 0.0001 for both hazard phases). The model demonstrated increased probability of HMII thrombosis as LDH trended upward, with steep changes in LDH trajectory paralleling trajectories in probability of pump thrombosis. The most important baseline variables predictive of the longitudinal pattern of LDH were higher bilirubin, higher pre-implant LDH, and older age. The effect of some pre-implant variables such as sodium on the post-implant LDH longitudinal pattern differed across time. CONCLUSIONS:Longitudinal trends in surveillance LDH for patients on HMII support are useful for dynamic prediction of pump thrombosis, both early after implant and late. Incorporating upward and downward trends in LDH that dynamically update a model of LVAD thrombosis risk provides a useful tool for clinical management and decisions.

BACKGROUND:The national opioid epidemic may have expanded the donor pool for lung transplantation, but concerns remain regarding infectious risks and allograft function. This study compared donor/recipient characteristics, outcomes, and reasons for organ discard between overdose death donors (ODD) and all other mechanism-of-death donors. METHODS:Data on adult lung transplants from 2000-2017 were provided by the Scientific Registry of Transplant Recipients. Pulmonary allografts used in multiple organ transplantations were excluded. Donor/recipient demographics, outcomes, and organ discard were analyzed with regards to ODD since 2010. Discard analysis was limited to donors who had at least one organ transplanted but their pulmonary allografts discarded. RESULTS:From 2010-2017, 7.3% (962/13,196) of lung transplantations were from ODD, over a 3-fold increase from the 2.1% (164/7,969) in 2000-2007. ODD were younger but more likely to have a history of smoking, hepatitis C, or an abnormal bronchoscopy finding. Overall survival was similar between ODD and non-ODD groups. ODD of discarded pulmonary allografts were younger and more likely to be hepatitis C positive, but were less likely to have a history of smoking than their non-ODD counterparts. CONCLUSIONS:Rates of ODD utilization in lung transplantation have increased in accordance with the opioid epidemic, but there remains a significant pool of ODD pulmonary allografts with favorable characteristics that are discarded. With no significant difference in survival between ODD and non-ODD recipients, further expansion of this donor pool may be appropriate and pulmonary allografts should not be discarded based solely on ODD status.

BACKGROUND:The national opioid epidemic has expanded the donor pool for heart transplantation, but concerns remain regarding infectious risk and allograft function. This study compared donor and recipient characteristics, outcomes, and reasons for organ discard between overdose-death donors (ODDs) and donors with all other mechanism of death. METHODS:Data on adult cardiac transplants from 2010 to 2017 were provided by the Scientific Registry of Transplant Recipients. Cardiac allografts used in multiple organ transplantations were excluded. Recipient and donor characteristics and organ discard were analyzed with regard to ODDs. Kaplan-Meier curves and log-rank tests described mortality survival. RESULTS:A total of 1,710 of 15,904 (10.8%) cardiac transplantations were from ODDs, approximately a 10-fold increase from 2000 (1.2%). ODDs were more frequently older than 40 years of age (87.2% vs 70.1%; p < 0.001), had higher rates of substance abuse, were more likely hepatitis C positive (1.3% vs 0.2%; p < 0.001), and less frequently required inotropic support at the time of procurement (38.4% vs 44.8%; p < 0.001). Overall survival was not different between the groups (p = 0.066). Discarded ODD allografts were more likely to be hepatitis C positive (30.8% vs 5.3%; p < 0.001) and to be identified as conveying increased risk by the Public Health Services (63.3% vs 13.2%; p < 0.001), but they were less likely to be discarded because of a diseased organ state (28.2% vs 36.1%; p < 0.001). CONCLUSIONS:Rates of ODDs have increased corresponding with the worsening opioid epidemic. Even though ODDs have higher rates of hepatitis C, cardiac allograft quality indices are favorable, and recipient outcomes are similar when compared with non-ODDs, a finding indicating that greater use of this donor pool may be appropriate.