Financial impact of donation after circulatory death heart transplantation: A single-center analysis.

INTRODUCTION: Clinical success of donation after circulatory death (DCD) heart transplantation is leading to growing adoption of this technique. In comparison to procurement from a brain-dead donor, DCD requires additional resources. The economic impact of DCD heart transplantation from the hospital perspective is not well known. METHODS: We compared the financial data of patients who received DCD allografts to those who received a DBD organ at our institution from January 1, 2021 to December 31, 2022. We also compared the cost of ex-situ machine perfusion to in-situ organ perfusion employed during DCD recovery. RESULTS: We performed 58 DBD and 22 DCD heart-alone transplantations during the study period. Out of 22 DCD grafts, 16 were recovered with thoracoabdominal normothermic regional perfusion (TA-NRP) and six with direct procurement followed by normothermic machine perfusion (DP-NMP). The contribution margin per case for DBD versus DCD was $234,362 and $235,440 (P = .72). The direct costs did not significantly differ between the two groups ($171,949 and 186,250; P = .49). In comparing the two methods of procuring hearts from DCD donors, the direct cost of TA-NRP was $155,955 in comparison to $223,399 for DP-NMP (P = .21). This difference translated into a clinically meaningful but not statistically significant greater contribution margin for TA-NRP ($242, 657 vs. $175,768; P = .34). CONCLUSIONS: Our data showed that the adoption of DCD procurement did not have a negative financial impact on the contribution margin in our institution. Programs considering starting DCD heart transplantation, and those who are currently performing DCD procurement should evaluate their own financial situation.

Impact of donation after circulatory death heart transplantation on waitlist outcomes and transplantation activity.

INTRODUCTION: Donation after circulatory death (DCD) heart transplantation has been shown to have comparable outcomes to transplantation using brain death donors (DBDs). This study evaluates the impact of this alternative source of allografts on waitlist mortality and transplant volume. METHODS: We compared waitlist mortality and transplant rates in patients who were registered before (2019 period) and after we adopted DCD heart transplantation (2021 period). RESULTS: We identified 111 patients who were on the waiting list in 2019 and 77 patients who were registered during 2021. Total number of donor organ offers received in 2019 was 385 (178 unique donors) versus 3450 (1145 unique donors) in 2021. More than 40% of all donors in 2021 were DCDs. Waitlist mortality was comparable for patients in 2019 and 2021 (18/100 person-years in 2019 vs. 26/100 person-years in 2021, p = .49). The transplant rate was 67/100 person-years in 2019 versus 207/100 person-years in 2021 (p < .001). After adjusting for acuity status, gender, blood type, and weight, patients listed in 2021 had 2.08 times greater chance of transplantation compared to patients listed in 2019 (HR 2.08, 95% confidence interval [CI] 1.26-3.45, p = .004). CONCLUSIONS: Use of DCD donor hearts significantly increased heart transplant rate in our institution.

Successful lung transplantation with graft recovered after thoracoabdominal normothermic perfusion from donor after circulatory death.

Lung transplantation with lungs procured from donors after circulatory death (DCD) has been established as an alternative technique to traditional donation after brain death (DBD) with comparable outcomes. Recently, in situ thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a novel technique employed in the procurement of cardiac allografts after circulatory death. TA-NRP, in contrast to ex situ machine perfusion, has the advantage of allowing in situ assessment of donor organs prior to final acceptance. However, there are some concerns that this technique may adversely impact the quality of lung allografts. Here, we present a case of a successful bilateral sequential lung transplantation in a patient with postinflammatory pulmonary fibrosis due to acute respiratory distress syndrome (ARDS), with lungs procured after normothermic in situ lung perfusion. Apart from the lungs, heart, liver, and kidneys were also successfully transplanted from this donor.

Involvement of ischemia-driven 5-lipoxygenase-resolvin-E1-chemokine like receptor-1 axis in the resolution of post-coronary artery bypass graft inflammation in coronary arteries.

AIMS: Expression status of pro-resolvin lipid mediators (PLM) and receptors in the post-Coronary artery bypass grafting (CABG) coronary arteries are largely unknown. Here, we aim to investigate the expression of the enzymes involved in PLM synthesis and their receptors in the atherosclerotic post-CABG swine (AS) left anterior descending (LAD) compared to without CABG (LAD-AS), and in isolated coronary artery smooth muscle cells (CASMCs) cultured under ischemia. METHODOLOGY: The arteries of interest were harvested from post-CABG atherosclerotic swine and the histomorphology and the expression status of key PLM mediators were quantified using immunostaining. Smooth muscle cells (SMCs) were cultured under ischemia and confirmed the expression on PLM mediators at transcript and protein level. RESULTS: The histomorphometric analysis revealed considerable alterations in the tissue architecture in LAD-CABG and LAD-AS arteries compared to control. PLM synthetic enzyme 5-lipoxygenases (5LO) was significantly upregulated in LAD-CABG and LAD-AS whereas the other enzymes including 12LO, 15LO, and cyclooxygenase-2, and the receptors including Chemokine like receptor 1 (ChemR23), 7-transmembrane G-protein coupled receptor-18 (GPCR18), GPCR120 were decreased in LAD-CABG than control. LO enzymes and PLM receptors were upregulated in ischemic CASMCs with respect to control. Western blot showed the upregulation of 5LO, and ChemR23. Additionally, higher level of resolvin-E1 (RvE1) was observed in ischemic control CASMCs which was decreased following reperfusion. CONCLUSION: These findings suggest that the CASMCs withstand the ischemia-triggered proinflammatory episodes by increasing the secretion of RvE1 mediated through 5LO and ChemR23 signaling.

Characteristics of venous-venous extracorporeal membrane oxygenation related bloodstream infections.

BACKGROUND: Infectious complications have been shown to increase the morbidity of venous-venous extracorporeal membrane oxygenation (VV-ECMO) population, including the use of right ventricular assist devices. AIM: We aimed to evaluate our VV-ECMO population for ECMO related bloodstream infections (E-BSI) and characteristics that affect risk and overall outcomes. METHODS: A retrospective chart review of adult patients (>18 years of age)supported with VV ECMO was conducted. Demographic data as well as antimicrobial use and presecence of bacteremia was collected. RESULTS: We report a low infection rate of 2.7%. CONCLUSIONS: We postulate our low BSI rate may be due to our use of perioperative antimicrobials as well as a majority of our cannulations occurring in the operating room. We do not routinely utilize prophylactic antimicrobials on ECMO. Further investigation into trends, risks, and outcomes related to E-BSI is needed.

In a large-volume multidisciplinary setting individual surgeon volume does not impact LVAD outcomes.

BACKGROUND: In complex operations surgeon volume may impact outcomes. We sought to understand if individual surgeon volume affects left ventricular assist device (LVAD) outcomes. METHODS: We reviewed primary LVAD implants at an experienced ventricular assist devices (VAD)/transplant center between 2013 and 2019. Cases were dichotomized into a high-volume group (surgeons averaging 11 or more LVAD cases per year), and a low-volume group (10 or less per year). Propensity score matching was performed. Survival to discharge, 1-year survival, and incidence of major adverse events were compared between the low- and high-volume groups. Predictors of survival were identified with multivariate analysis. RESULTS: There were 315 patients who met inclusion criteria-45 in the low-volume group, 270 in the high-volume group. There was no difference in survival to hospital discharge between the low (91.9%) and high (83.3%) volume matched groups (p = .22). Survival at 1-year was also similar (85.4% vs. 80.6%, p = .55). There was no difference in the incidence of major adverse events between the groups. Predictors of mortality in the first year included: age (hazards ratio [HR]: 1.061, p < .001), prior sternotomy (HR: 1.991, p = .01), increasing international normalized ratio (HR: 4.748, p < .001), increasing AST (HR: 1.001, p < .001), increasing bilirubin (HR: 1.081, p = .01), and preoperative mechanical ventilation (HR: 2.662, p = .005). Individual surgeon volume was not an independent predictor of discharge or 1-year survival. CONCLUSION: There was no difference in survival or adverse events between high and low volume surgeons suggesting that, in an experienced multidisciplinary setting, low-volume VAD surgeons can achieve similar outcomes to their high-volume colleagues.

Combination plate and band fixation for primary closure in bilateral lung transplantation.

BACKGROUND: Sternal complications are common following transverse thoracosternotomy in patients undergoing bilateral lung transplantation. We present a single-institution experience using a next generation rigid fixation system for primary sternal closure following transverse sternotomy for bilateral lung transplantation. METHODS: Retrospective review was performed on all patients who had bilateral sequential lung transplants utilizing a transverse thoracosternotomy from 2016 to 2020. Demographics, baseline characteristics, peri-operative data, and outcomes were collected, reviewed and summarized. Two groups of patients were identified: wire cerclage (Group A), combination plate-and-band rigid fixation (Group B). The primary outcome was sternal complications, which were divided into mechanical and non-mechanical. RESULTS: Twenty-two patients met inclusion criteria. Three patients (13.6%) were in Group A, nineteen patients (86.4%) in Group B. Two patients in each Group A (66.6%) and Group B (10.5%) experienced a sternal complication. Sternal complications included sternal dehiscence (2), sternal malunion (1), and surgical site infection (1). One patient with plate-and-band fixation (5.2%) had a mechanical sternal complication. Three patients required reoperation secondary to sternal complication. CONCLUSIONS: The utilization of a combination plate-and-band rigid fixation system for primary closure is safe and may be an effective method to reduce sternal complications following transverse thoracosternotomy for lung transplantation.

Impact of temporary mechanical circulatory support for early graft failure on post-heart transplantation outcomes.

Although temporary mechanical circulatory support (tMCS) for hemodynamic failure following heart transplantation is associated with increased early morbidity and mortality, the impact of etiology of graft dysfunction and long-term clinical implications are less well known. The objective of our study was to evaluate outcomes in patients who required venoarterial extracorporeal membrane oxygenation (VA ECMO) or temporary right ventricular assist device (RVAD) support for either primary or secondary early graft dysfunction. Hospital mortality in 27 patients who required tMCS following heart transplantation at our institution between 2007 and 2017 was 56%, 30% in patients with right ventricular dysfunction secondary to increased afterload, 60% in patients with primary graft dysfunction, and 100% in patients with graft failure secondary to coagulopathy with intraoperative bleeding or overwhelming sepsis. Conditional 1-year and 5-year survival was comparable between patients with, and without, the need for post-transplantation support with tMCS (98% and 89%; 92% and 65% at 1 and 5 years, P = .21). Etiology of early graft failure plays an important part in determining the short-term post-heart transplantation outcome. Although complications associated with tMCS use, such as renal dysfunction and infection, extend beyond index transplant hospitalization, long-term conditional survival is not compromised.

Role of Invasive Functional Assessment in Surgical Revascularization of Coronary Artery Disease.

In patients with stable coronary artery disease, percutaneous coronary intervention is associated with improved outcomes if the lesion is deemed significant by invasive functional assessment using fractional flow reserve. Recent studies have shown that a revascularization strategy using instantaneous wave-free ratio is noninferior to fractional flow reserve in patients with intermediate-grade stenoses. The decision to perform coronary artery bypass grafting surgery is usually based on anatomic assessment of stenosis severity by coronary angiography. The data on the role of invasive functional assessment in guiding surgical revascularization are limited. In this review, we discuss the diagnostic and prognostic significance of invasive functional assessment in patients considered for coronary artery bypass grafting. In addition, we critically discuss ongoing and future clinical trials on the role of invasive functional assessment in surgical revascularization.

Can we expect improvements in outcomes with centrifugal vs axial flow left ventricular assist devices in patients transitioned from extracorporeal life support?

BACKGROUND: Several patient-related characteristics have been associated with inferior outcomes following durable left ventricular assist device (LVAD) implantation in patients transitioned from venoarterial extracorporeal membrane oxygenation (VA ECMO). The impact of LVAD pump type used is less well-known. METHODS: We compared outcomes between patents who received axial and centrifugal flow LVADs following stabilization with VA ECMO. RESULTS: From January 2011 to December 2018, we implanted 28 LVADs in patients transitioned from VA ECMO. This included 17 axial flow devices (HeartMate II LVAD, Abbott Laboratories, Chicago, IL) and 11 centrifugal flow pumps (eight HeartWare HVADs; Medtronic, Minneapolis, MN and three HeartMate 3 LVAS pumps; Abbott Laboratories, Chicago, IL). There was no difference in hospital mortality (23.5% vs 18.2%, P = .74) or 1-year survival (P = .31) between the devices. There were no differences in adverse event rates between the two pump types, apart from a higher rate of gastrointestinal bleeding in patients who received centrifugal flow pumps (1.44 events per 100 patient-months vs 14.67 events per 100 patient-months, P = .010). Preimplantation levels of alanine aminotransferase (hazard ratio [HR], 1.001; 95% confidence interval [CI], 1.000 to 1.002; P = .004) and elevated serum creatinine level (HR, 3.480; 95% CI, 1.121-10.807; P = .031) emerged as significant predictors of decreased 1-year survival. CONCLUSIONS: Preimplantation optimization of end-organ function is the single most important determinant of successful post-LVAD survival in patients transitioned from extracorporeal life support. There is no association of pump type with LVAD outcomes up to 1-year post implantation.

Does concomitant tricuspid valve intervention at the time of left ventricular assist device placement for patients with significant tricuspid regurgitation lead to improved outcomes compared to isolated left ventricular assist device placement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients with advanced heart failure (HF) and moderate to severe functional tricuspid regurgitation (TR) undergoing left ventricular assist device (LVAD) placement is concomitant tricuspid valve intervention (TVI) superior for the clinical outcomes of survival, right ventricular failure, rehospitalizations for HF, functional status, and quality of life?' Altogether, 56 papers were found using the reported search, of which 12 papers represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Our search found no significant clinical benefit for concomitant TVI at the time of LVAD placement. We conclude that patient with moderate-to-severe TR should not routinely undergo concomitant TVI with LVAD placement.

Tricuspid regurgitation in the setting of LVAD support.

Tricuspid valve regurgitation (TR) is a common complication of end-stage heart failure. Increased pulmonary venous pressures caused by left ventricular (LV) dysfunction can result in a progressive dilation of the right ventricle and tricuspid valve annulus, resulting in functional TR. Here, we review what is known about TR in the setting of severe LV dysfunction necessitating long-term mechanical support with left ventricular assist devices (LVADs), including the occurrence of significant TR, its pathophysiology, and natural history. We examine the impact of uncorrected TR on LVAD outcomes and the impact of tricuspid valve interventions at the time of LVAD placement, revealing that TR frequently improves after LVAD placement with or without concomitant tricuspid valve intervention such that the benefit of concomitant intervention remains controversial. We summarize the current evidence on which to base medical decisions and provide recommendations for future directions of study to address outstanding questions in the field.

1,1-Difluoroethane Hydrocarbon Cardiomyopathy.

1,1-Difluoroethane (DFE) cardiomyopathy results from the direct inhalation of toxic halogenated hydrocarbons. We present a case series of acute DFE cardiomyopathy illustrating the typical presentation of severe DFE cardiomyopathy along with a detailed description of its mechanism of injury. (Level of Difficulty: Advanced.).

Does Tracheostomy Improve Outcomes in Those Receiving Venovenous Extracorporeal Membrane Oxygenation?

Patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) often require extended periods of ventilation. We examined the role of tracheostomy on outcomes of patients supported with VV-ECMO. We reviewed all patients at our institution who received VV-ECMO between 2013 and 2019. Patients who received a tracheostomy were compared with VV-ECMO-supported patients without tracheostomy. The primary outcome measure was survival to hospital discharge. Secondary outcome measures included length of intensive care unit (ICU) and hospital stay and adverse events related to the tracheostomy procedure. Multivariable analysis was performed to identify predictors of in-hospital mortality. We dichotomized patients receiving tracheostomy into an "early" and "late" group based on median days to tracheostomy following ECMO cannulation and separate analysis was performed. One hundred and fifty patients met inclusion criteria, 32 received a tracheostomy. Survival to discharge was comparable between the groups (53.1% vs. 57.5%, p = 0.658). Predictors of mortality on multivariable analysis included Respiratory ECMO Survival Prediction (RESP) score (odds ratio [OR] = 0.831, p = .015) and blood urea nitrogen (BUN) (OR = 1.026, p = 0.011). Tracheostomy performance was not predictive of mortality (OR = 0.837, p = 0.658). Bleeding requiring intervention occurred in 18.7% of patients following tracheostomy. Early tracheostomy (<7 days from the initiation of VV-ECMO) was associated with shorter ICU (25 vs. 36 days, p = 0.04) and hospital (33 vs. 47, p = 0.017) length of stay compared with late tracheostomy. We conclude that tracheostomy can be performed safely in patients receiving VV-ECMO. Mortality in these patients is predicted by severity of the underlying disease. Performance of tracheostomy does not impact survival. Early tracheostomy may decrease length of stay.

Synergistic Detrimental Effects of Cigarette Smoke, Alcohol, and SARS-CoV-2 in COPD Bronchial Epithelial Cells.

Lung conditions such as COPD, as well as risk factors such as alcohol misuse and cigarette smoking, can exacerbate COVID-19 disease severity. Synergistically, these risk factors can have a significant impact on immunity against pathogens. Here, we studied the effect of a short exposure to alcohol and/or cigarette smoke extract (CSE) in vitro on acute SARS-CoV-2 infection of ciliated human bronchial epithelial cells (HBECs) collected from healthy and COPD donors. We observed an increase in viral titer in CSE- or alcohol-treated COPD HBECs compared to untreated COPD HBECs. Furthermore, we treated healthy HBECs accompanied by enhanced lactate dehydrogenase activity, indicating exacerbated injury. Finally, IL-8 secretion was elevated due to the synergistic damage mediated by alcohol, CSE, and SARS-CoV-2 in COPD HBECs. Together, our data suggest that, with pre-existing COPD, short exposure to alcohol or CSE is sufficient to exacerbate SARS-CoV-2 infection and associated injury, impairing lung defences.

Utilization of Paragonix Sherpapak Cardiac Transport System for the Preservation of Donor Hearts After Circulatory Death.

BACKGROUND: Donation after circulatory death (DCD) heart transplantation is being increasingly adopted by transplant centers. The optimal method of DCD heart preservation during transport after in situ thoracoabdominal normothermic regional perfusion (TA-NRP) is not known. METHODS: We evaluated our experience with the Paragonix SherpaPak Cardiac Transport System (SCTS) for the transport of DCD cardiac allografts after TA-NRP recovery between January 2021 and December 2022. We collected and evaluated donor characteristics, allograft ischemic intervals, and recipient baseline demographic and clinical variables, and short-term outcomes. RESULTS: Twelve recipients received DCD grafts recovered with TA-NRP and transported in SCTS during the study period. The median age of 10 male and 2 female donors was 32 years (min 15, max 38). The median duration of functional warm ischemia was 12 minutes (min 8, max 22). Hearts were preserved in SCTS for a median of 158 minutes (min 37, max 224). Median recipient age was 61 years (min 28, max 70). Ten recipients (83%) survived to hospital discharge, with one death attributable to graft dysfunction (8%). The median vasoactive-inotropic (VIS) score at 72 hours post-transplantation of the entire cohort was 6 (min 0, max 15). The median length of intensive care unit stay in hospital survivors was 5 days (min 3, max 17) days and hospital stay 17 days (min 9, max 37). CONCLUSIONS: The Paragonix SCTS provides efficacious preservation of DCD grafts for ≥3.5 hours. Organs transported with this device showed satisfactory post-transplantation function.

Patient-specific computational simulation of coronary artery bypass grafting.

INTRODUCTION: Coronary artery bypass graft surgery (CABG) is an intervention in patients with extensive obstructive coronary artery disease diagnosed with invasive coronary angiography. Here we present and test a novel application of non-invasive computational assessment of coronary hemodynamics before and after bypass grafting. METHODS AND RESULTS: We tested the computational CABG platform in n = 2 post-CABG patients. The computationally calculated fractional flow reserve showed high agreement with the angiography-based fractional flow reserve. Furthermore, we performed multiscale computational fluid dynamics simulations of pre- and post-CABG under simulated resting and hyperemic conditions in n = 2 patient-specific anatomies 3D reconstructed from coronary computed tomography angiography. We computationally created different degrees of stenosis in the left anterior descending artery, and we showed that increasing severity of native artery stenosis resulted in augmented flow through the graft and improvement of resting and hyperemic flow in the distal part of the grafted native artery. CONCLUSIONS: We presented a comprehensive patient-specific computational platform that can simulate the hemodynamic conditions before and after CABG and faithfully reproduce the hemodynamic effects of bypass grafting on the native coronary artery flow. Further clinical studies are warranted to validate this preliminary data.

Transapical ischemic ventricular septal defect repair with simultaneous centrifugal left ventricular assist device placement: A case report.

INTRODUCTION AND IMPORTANCE: Post-infarct ventricular septal defect (PIVSD) is an often-fatal complication of myocardial infarction despite the use of temporary mechanical circulatory support. CASE PRESENTATION: A 46-year-old male presented with myocardial infarction complicated by PIVSD. Clinical course was characterized by declining systolic function and hemodynamic instability. To provide hemodynamic support, a ventricular assist device was placed at surgical repair of the defect. The patient successfully recovered with no complications 21 months post-repair. He has undergone evaluation for heart transplantation. CLINICAL DISCUSSION: Mortality among patients with PIVSD is high. For patients with cardiogenic shock at the time of defect repair, concomitant ventricular assist device therapy shows promise to decrease morbidity through durable hemodynamic support following surgery. CONCLUSION: Placement of a durable left ventricular assist device (LVAD) at the time of PIVSD repair through a single ventriculotomy may be an effective strategy for this lethal condition.

A Comprehensive Review of Mechanical Circulatory Support Devices.

Treatment strategies to combat cardiogenic shock (CS) have remained stagnant over the past decade. Mortality rates among patients who suffer CS after acute myocardial infarction (AMI) remain high at 50%. Mechanical circulatory support (MCS) devices have evolved as novel treatment strategies to restore systemic perfusion to allow cardiac recovery in the short term, or as durable support devices in refractory heart failure in the long term. Haemodynamic parameters derived from right heart catheterization assist in the selection of an appropriate MCS device and escalation of mechanical support where needed. Evidence favouring the use of one MCS device over another is scant. An intra-aortic balloon pump is the most commonly used short-term MCS device, despite providing only modest haemodynamic support. Impella CP® has been increasingly used for CS in recent times and remains an important focus of research for patients with AMI-CS. Among durable devices, Heartmate® 3 is the most widely used in the USA. Adequately powered randomized controlled trials are needed to compare these MCS devices and to guide the operator for their use in CS. This article provides a brief overview of the types of currently available MCS devices and the indications for their use.

Translational model of vein graft failure following coronary artery bypass graft in atherosclerotic microswine.

OBJECTIVE: Vein graft failure is a major complication following coronary artery bypass graft surgery. There is no translational model to understand the molecular mechanisms underlying vein-graft failure. We established a clinically relevant bypass graft model to investigate the underlying pathophysiological mechanisms of vein-graft failure and identify molecular targets for novel therapies. METHODS: Six female Yucatan microswine fed with high cholesterol diet underwent off-pump bypass, using superficial epigastric vein graft, which was anastomosed to an internal mammary artery and distal left anterior descending artery. Vein-graft patency was examined 10-months after bypass surgery by echocardiography, coronary angiography, and optical coherence tomography followed by euthanasia. Coronary tissues were collected for histomorphometry studies. RESULTS: Atherosclerotic microswine were highly susceptible to sudden ventricular fibrillation with any cardiac intervention. Two out of six animals died during surgery due to ventricular fibrillation. Selection of the anesthetics and titration of their doses with careful use of inotropic drugs were the key to successful swine cardiac anesthesia. The hypotensive effects of amiodarone and the incidence of arrhythmia were avoided by the administration of magnesium sulfate. The vein-graft control tissue displayed intact endothelium with well-organized medial layer. The grafted vessels revealed complete occlusion and were covered with fibrous tissues. Expression of CD31 in the graft was irregular as the layers were not clearly defined due to fibrosis. CONCLUSION: This model represents the clinical vein-graft failure and offers a novel platform to investigate the underlying molecular mechanisms of vein-graft disease and investigate novel therapeutic approaches to prevent its progression.