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OBJECTIVES: Percutaneous pulmonary artery cannulas, used as inflow for left ventricular venting or as outflow for right ventricular mechanical circulatory support, are easily and rapidly deployable with transesophageal and fluoroscopic guidance. METHODS: We chose to review our institutional and technical experience with all right atrium to pulmonary artery cannulations. RESULTS: Based on the review, we describe 6 right atrium to pulmonary artery cannulation strategies. They are divided into total right ventricular assist support, partial right ventricular assist support, and left ventricular venting. A single limb cannula or a dual lumen cannula can be used for right ventricular support. CONCLUSIONS: In the right ventricular assist device configuration, percutaneous cannulation may prove beneficial in cases of isolated right ventricular failure. Conversely, pulmonary artery cannulation can be used for left ventricular venting as drainage to a cardiopulmonary bypass or extracorporeal membrane oxygenation circuit. This article can be used as a reference for the technical aspects of cannulation, decision-making in patient selection, and management of patients in these clinical scenarios.

Minimally invasive mitral valve repair has been proven to be a safe alternative to open sternotomy and may be accomplished through classic endoscopic and robotic endoscopic approaches. Outcomes across different minimally invasive techniques have been insufficiently described. We compare early and late clinical outcomes across matched patients undergoing robotic endoscopic and classic endoscopic repair.From 2011 to 2020, 786 patients underwent minimally invasive mitral surgery, from which we were able to generate 124 matched patients (62 patients in each cohort). Clinical results were then compared between the two matched populations. Survival analysis was used to compare freedom from mortality to 10 years among matched classic endoscopic and robotic endoscopic mitral valve repair cohorts and to calculate freedom from moderate or severe mitral insufficiency at latest follow-up. Histograms of cardiopulmonary bypass (CPB) and aortic cross-clamp times were constructed, and mean bypass and cross-clamp times were compared between classic endoscopic and robotic endoscopic cohorts.There was no difference in early or late mortality at 10 years in either cohort. Freedom from moderate or severe mitral regurgitation or mitral valve replacement at last echocardiogram was 86.4%Index mitral valve surgery via a classic endoscopic approach yields similar clinical outcomes when compared to robotic endoscopic surgery. We demonstrate that both classic endoscopic and robotic endoscopic approaches allow repair of degenerative mitral valves with excellent short- and medium-term outcomes in a tertiary referral center.

On June 3, 2021 Medtronic, Inc announced discontinuation of the HVAD left ventricular assist device. The purpose of this analysis was to provide summary data on surgical risks of HVAD to HeartMate 3 exchange and compare survival after HVAD to HeartMate 3 exchange to survival after primary HVAD implantation.Three cohorts within The Society of Thoracic Surgeons Intermacs database were identified: primary HVAD implant cohort (January 2017 to March 2021, n = 3797), HVAD to HeartMate 3 exchange cohort (December 2017 to March 2021, n = 45), and HVAD to HVAD exchange cohort (January 2017 to March 2021, n = 234). Mortality after HVAD to HeartMate 3 exchange was modeled and compared with the constant hazard phase for risk of mortality while on continued HVAD support. As a secondary analysis outcomes and survival were compared between patients who underwent HVAD to HeartMate 3 and HVAD to HVAD exchange.HVAD to HeartMate 3 exchange was associated with significantly reduced survival compared with survival while remaining on HVAD support (6 months after exchange, 73.8% [70% confidence interval, 68.6-77.8] vs 79.0% [70% confidence interval, 78.3-79] for continued HVAD support). Compared with HVAD to HVAD exchange, survival was higher after replacement with HeartMate 3 (1 year: 85.9% [70% confidence interval, 79.5-90.5] vs 66.6% [70% confidence interval, 63.0-70.0], P = .009).Compared with continued support on HVAD, an exchange to HeartMate 3 was found to be associated with a significant increase in mortality. For patients who required pump exchange on HVAD support, exchange to HeartMate 3 demonstrated superior survival. Currently there is insufficient evidence to support elective exchange from an HVAD to HeartMate 3.

Left ventricular assist devices (LVADs) improve survival and quality of life for patients with advanced heart failure but are associated with high rates of thromboembolic and hemorrhagic complications. Antithrombotic therapy is required following LVAD implantation, though practices vary. Identifying a therapeutic strategy that minimizes the risks of thromboembolic and hemorrhagic complications is critical to optimizing patient outcomes and is an area of active investigation. This paper reviews strategies for initiating and maintaining antithrombotic therapy in durable LVAD recipients, focusing on those with centrifugal-flow devices.

Background: Demand for donor hearts and lungs exceeds their supply. Extended Criteria Donor (ECD) organs are used to help meet this demand, but their impact on heart-lung transplantation outcomes is poorly characterized. Methods and results: The United Network for Organ Sharing was queried for data on adult heart-lung transplantation recipients (n = 447) from 2005‒2021. Recipients were stratified based on whether they received ECD hearts and/or lungs. Morbidity was analyzed using Kruskal-Wallis, chi-square, and Fisher’s exact tests. Mortality was analyzed using Kaplan-Meier estimation, log-rank tests and Cox regression. Sixty-five (14.5%) patients received two ECD organs, 134 (30.0%) received only an ECD lung, and 65 (14.5%) only an ECD heart. Recipients of two ECD organs were older, more likely to have diabetes, and more likely transplanted from 2015‒2021 (p < 0.05). Groups did not differ by pre-transplant diagnosis, intensive care unit disposition, life support use, or hemodynam-ics. Group five-year survival rates ranged from 54.5% to 63.2% (p = 0.428). Groups did not differ by 30-day mortality, strokes, graft rejection, or hospital length of stay. Conclusions: Using ECD hearts and/or lungs for heart-lung transplantation is not associated with increased mortality and is a safe strategy for increasing donor organ supply in this complex patient population.

The coronavirus disease 2019 (COVID-19) pandemic continues to disrupt the provision of cardiac procedural services due to overwhelming interval surges in COVID-19 cases and the associated crisis of cardiac intervention deferment. Despite the availability of widespread testing, highly efficacious vaccines, and intensive public health efforts, the pandemic is entering its third year, where new severe acute respiratory syndrome-coronavirus-2 variants have increased the likelihood that patients scheduled for a cardiac intervention will contract COVID-19 in the perioperative period. The Society of Thoracic Surgeons (STS) Workforce on Critical Care, the STS Workforce on Adult Cardiac and Vascular Surgery, and the Canadian Society of Cardiac Surgeons have developed this document, endorsed by the STS and affirmed by the Society of Cardiovascular Angiography and Interventions and the Canadian Association of Interventional Cardiology, to provide guidance for cardiac procedure deferment and intervention timing for preoperative patients diagnosed with COVID-19. This document is intended for the perioperative cardiac surgical team and outlines the present state of the pandemic, the impact of COVID-19 on intervention outcome, and offers a recommended algorithm for individualized cardiac procedure triage and timing.

Continuous-flow left ventricular assist devices (CF-LVAD) have been shown to enhance reverse remodeling and myocardial recovery in certain patients allowing for device removal. We sought to analyze the characteristics and describe outcomes of patients who underwent CF-LVAD explantation at a large academic center. We retrospectively identified all patients who underwent CF-LVAD explants due to recovery from 2006 to 2019. Patient baseline characteristics and data on pre- and postexplant evaluation were collected and analyzed. Of 421 patients who underwent CF-LVAD implantation, 13 underwent explantation (3.1%). Twelve HeartMate II and one HeartWare LVAD were explanted. All patients had nonischemic cardiomyopathy. Median time from heart failure diagnosis to LVAD implant was 12 months (interquartile range [IQR], 2-44) and the median time supported on LVAD was 22 months (IQR, 11-28). Two patients died within 30 days of explant. Three additional patients died during the follow-up period and all were noted to be nonadherent to medical therapy. After a mean follow-up duration of 5 years, overall survival was 52%. Mean pre-explant ejection fraction was 49%, which decreased at most recent follow-up to 32%. Mean pre-explant left ventricular internal diameter in diastole (LVIDD) was 4.37 cm and increased to 5.52 cm at most recent follow-up. Continuous-flow left ventricular assist device explantation is feasible and safe in select patients.

BACKGROUND The Society of Thoracic Surgeons (STS) Intermacs Registry represents a real-world data source of durable, left ventricular assist devices that can address knowledge gaps not informed through randomized clinical trials. We sought to compare survival with contemporary left ventricular assist device technologies using multiple analytic approaches to assess concordance of treatment effects and to validate prior STS Intermacs observations. METHODS Patients (≥19 years of age) enrolled into STS Intermacs between August 2017 and June 2019 were stratified by device type (continuous flow, centrifugal left ventricular assist device with hybrid levitation [CF-HL] or full magnetic levitation [CF-FML]). The primary outcome was 1-year survival assessed by 3 statistical methodologies (multivariable regression, propensity score matching, and instrumental variable analysis). RESULTS Of 4448 patients, 2012 (45.2%) received the CF-HL and 2436 (54.8%) received the CF-FML. One-year survival for the CF-FML was 88% vs 79% for the CF-HL (overall P < .001), with a hazard ratio for mortality of 3.18 for the CF-HL (P < .0001) after risk adjustment. With propensity score matching (n = 1400 each cohort), 1-year survival was 87% for the CF-FML vs 80% for the CF-HL, with a hazard ratio of 3.20 for mortality with the CF-HL (P < .0001) after risk adjustment. With an instrumental variable analysis, the probability of receiving the CF-HL was associated with a hazard ratio of 3.11 (P < .0001). CONCLUSIONS Statistical methodology using propensity score matching and instrumental variable analysis increased the robustness of observations derived from real-world data and demonstrates the feasibility of performing comparative effectiveness research using STS Intermacs. These analyses provide additional evidence supporting a survival benefit of the CF-FML vs CF-HL.

BACKGROUND: We hypothesized that long-term clinical and echocardiographic recovery of the impaired ventricle from pressure (aortic stenosis [AS]) and volume (aortic regurgitation [AR]) overload would be different after aortic valve replacement (AVR). METHODS: We compared the results of AVR in patients with a preoperative ejection fraction (EF) of 0.35 or less due to AS, AR, or mixed disease. We constructed a mixed-effects model of EF and left ventricular (LV) end-diastolic diameter (LVEDD) to understand ventricular recovery over the short- (in-hospital), intermediate- (3–6 months), and longer- (>24 months) terms. We sought to identify factors associated with clinical and echocardiographic recovery using multivariable analysis. RESULTS: Between July 2011 and 2017, 136 patients with a preoperative EF of 0.35 or less and severe AS (n = 83), severe AR (n = 18), or mixed AS and AR (n = 35) underwent AVR. There were 2 (1.5%) early deaths in the AS group. Survival at 1, 2, and 5 years did not differ between groups. Baseline EF did not differ between the groups but improved with markedly different trajectory and time course in the AS, AR, and mixed groups over time. LVEDD regressed in all patient cohorts, following a different pattern for AS and AR. Baseline EF and LVEDD predicted the long-term fate of the LV but did not determine survival. We identify factors associated with long-term survival. CONCLUSIONS: The pattern of LV recovery appears to be early in AS and delayed in AR. Baseline clinical factors, rather than echocardiographic status of the LV, appear to determine late survival.

Driveline infection (DLI) is a significant source of morbidity and mortality during left ventricular assist device (LVAD) support yet limited studies are available to describe the center-level prevalence, preventive practices, and their potential effectiveness.We surveyed LVAD centers in the United States to determine program burden and preventive practices for DLI during HeartMate (HM) 3 support. An online, anonymous, question-based survey was sent to expert providers at implanting centers. Only a single respondent completed the survey for each center. As an exploratory analysis, we compared specific DLI preventive practices between centers with low (≤10%) and high (10%) reported prevalence of DLI.Seventy-eight centers responded to the survey (response rate: 50%). Respondents were comprised of 37 (47%) heart failure cardiologists, 27 (35%) LVAD coordinators, and 14 (18%) cardiothoracic surgeons. The prevalence of DLI during HM3 was reported as ≤10% by 27 (35%), 11%-25% by 36 (46%), and25% by 16 (19%) centers. Thirteen (17%) centers had a body mass index threshold for device placement, 29 (37%) utilized a counter incision, 66 (81%) placed an anchor stitch, and 69 (88%) used an external device to stabilize the DL. Proportionally, more centers with a low DLI prevalence used a wound vacuum 6 (22%) versus 3 (6%, p = 0.03) than those with high DLI.Variation exists in reported prevalence and practices of preventing and managing driveline infections across centers during HM3 support. Further studies are warranted to develop and assess the effectiveness of standardized preventive strategies.

In the setting of chronic primary mitral regurgitation, the benefit of mitral valve repair over replacement is well established. However, data comparing outcomes for mitral valve surgery for endocarditis is limited. We sought to determine whether mitral valve repair offers traditional advantages over replacement in the endocarditis population. Retrospective review of our institutional mitral valve database (N = 8,181) was performed between 1998 and 2019 for all adult patients undergoing isolated mitral valve surgery for endocarditis. Patients were stratified by mitral valve repair or replacement and propensity score matching was performed to adjust for differences in baseline characteristics and degree of valve damage. Overall, 267 surgeries (124 repair, 153 replacement) met inclusion criteria during the study period. Following propensity matching, the repair cohort was associated with shorter initial ventilator times (5.6 vs 7.9 hours, p = 0.05), shorter ICU (28 vs 52 hours, p = 0.03), and hospital lengths of stays (7 vs 11 days, p0.01). Thirty-day mortality (0% vs 2.1%, p = 0.01) and 10-year survival (88% vs 86%, p = 0.55) were similar between cohorts. Patients in the repair cohort were less likely to require repeat mitral valve intervention at our institution for recurrent endocarditis than those in the replacement cohort (0% vs 10.6%, p = 0.03). Mitral valve repair is safe, when feasible, in the setting of isolated native valve endocarditis and may provide patients faster recovery. Experienced mitral surgeons should approach this patient population with a "repair if feasible" methodology.

Background Because of ongoing shortages of donors for heart transplantation, the use of donor candidates whose availabilities are the result of drug overdoses (ODs) has become increasingly prevalent, even though these donors carry a high preponderance of the now curable hepatitis C virus (HCV). This study investigated temporal trends and regional variabilities in HVC-positive (HCV+) allograft use in heart transplantation and assessed the relationship between the use of HCV+ graft donors and the use of OD donors as well as assessing waitlist and post-transplant outcomes. Methods and Results A retrospective review of the United Network for Organ Sharing database assessed adults listed for heart transplantation. Patients were stratified both temporally into pre-HCV and HCV eras related to HCV+ graft use trends and regionally by degree of HCV+ allograft use. Regions of high HCV+ donor use were associated with an increase in OD donor access by 7.8% across eras compared to 0.4% in low HCV+ donor-use regions. One-year waitlist mortality decreased from 4.7% to 2.5% across eras in high HCV+ donor-use regions (P= 0.001) and remained roughly the same as before in low HCV+ donor-use regions (3.0% vs 2.4%; P= 0.244.). Post-transplant survival at 1 year remained similar across eras. Conclusions HCV+ donor allograft use can help to optimize donor use, decreasing waitlist mortality without compromising early survival. Ongoing assessment is essential to ensure long-term safety and efficacy of using HCV+ donors.

There are limited data on the characteristics and clinical course of fungal infections in patients on durable left ventricular assist device (LVAD) support. We sought to further characterize the epidemiology and outcomes of LVAD patients with fungemia. We performed a retrospective review of patients receiving LVAD support from January 2012 through June 2020 at a large academic institution. Among 336 patients on LVAD support, five (1.4%) were diagnosed with fungemia during the study period. Three patients had diabetes with mean hemoglobin A1c 7.1% (R 6.6, 7.4). Fever and leukocytosis (mean white blood count 17.0 thousand/µL [R 12.5, 29.9]) were the most common symptoms. Fungemia was diagnosed early after LVAD implantation (mean 14.4 support days [R 2, 19]). All patients were infected with Candida species, and four isolates were susceptible to fluconazole. Central nervous system outcomes included an ischemic stroke, subarachnoid hemorrhage, and malignant hemorrhagic stroke. Two patients were successfully transplanted, and two patients on destination therapy remain on suppressive fluconazole. In conclusion, fungemia is a rare and severe complication in LVAD patients occurring early postimplant.

The coronavirus disease 2019 (COVID-19) pandemic continues to pose a significant threat to patients receiving advanced heart failure therapies. The current study was undertaken to better understand the relationship between obesity and outcomes of SARS-CoV-2 infection in patients with a left ventricular assist device (LVAD) or heart transplant. We performed a retrospective review of patients with a heart transplant or LVAD who presented to one of the participating 11 institutions between April 1 and November 30, 2020. Patients were grouped by body mass index (BMI) into obese (BMI ≥ 30 k/m2) and nonobese cohorts (BMI30 kg/m2). Multivariable logistic regression models were used to estimate effects of obesity on outcomes of interest. Across all centers, 162 heart transplant and 81 LVAD patients were identified; 54 (33%) and 38 (47%) were obese, respectively. Obese patients tended to have more symptoms at presentation. No differences in rates of hospitalization or ICU admission were noted. Obese patients with LVADs were more likely to require mechanical ventilation (39% vs. 8%, p0.05). No differences in renal failure or secondary infection were noted. Mortality was similar among heart transplant patients (11% [obese] vs. 16% [nonobese], p = 0.628) and LVAD patients (12% vs. 15%, p = 1.0). BMI was not associated with increased adjusted odds of mortality, ICU admission, or mechanical ventilation (all p0.10). In summary, acute presentations of SARS-CoV-2 among heart transplant and LVAD recipients carry a significantly higher mortality than the general population, although BMI does not appear to impact this. Further studies on the longer-term effects of COVID-19 on this population are warranted.

BACKGROUND Predicted heart mass (PHM) is currently the most reliable metric for donor-recipient size matching in heart transplantation. Undersizing PHM donor-recipient match more than 20% independently predicts reduced survival. However, it is unclear if this is the case in obese recipients, in whom size matching can be challenging. We examined the use of PHM undersized hearts in obese recipients and assessed its impact on survival. METHODS The United Network for Organ Sharing database was queried for adult patients undergoing heart transplantation from 1995 to 2020. Obese recipients (BMI ≥ 30) were categorized based on donor-recipient PHM match ≤-20% (undersized) or >-20% (size-matched). Nearest-neighbor propensity score matching was performed to adjust for baseline differences between cohorts. Temporal outcomes were compared by Kaplan-Meier survival analysis. RESULTS A total of 13,668 obese recipients met inclusion criteria, with 9.6% receiving undersized and 90.4% receiving size-matched hearts. The proportion of undersized donor hearts in obese recipients significantly decreased over the study period (16.2% [1995] to 7.4% [2019], NP-trend < 0.001). Propensity-score matching resulted in 984 well-matched pairs of undersized and size-matched obese recipients. Recipients of undersized hearts saw similar 30-day mortality (5.5% vs 6.0%, p= 0.11) and re-transplantation rates (1.2% vs 1.2%, p = 1.00) as size-matched recipients. Survival at 1 year (88.4% vs 87.9%, p = 0.14), and 15 years (35.1% vs 31.0%, p = 0.12) was similar across cohorts. CONCLUSIONS A decreasing proportion of PHM undersized hearts are being utilized in obese recipients. However, utilizing PHM undersized hearts in obese recipients was not associated with a detriment in survival.

OBJECTIVES The decision to perform simultaneous heart–kidney transplant (HKT) rather than isolated heart transplant (IHT) for patients with advanced kidney disease is challenging. Limited data exist to guide this decision in obese patients. We sought to compare mortality after HKT and IHT in obese patients with non-dialysis-dependent kidney disease. METHODS The United Network for Organ Sharing was queried for data on adult heart transplant recipients from 2000 to 2022. Inclusion criteria were obesity, estimated glomerular filtration rate RESULTS A total of 289 HKT and 1920 IHT recipients met inclusion criteria. Heart–kidney recipients had higher baseline creatinine and rates of intensive care unit disposition than IHT recipients (both standardized mean differences >0.10). Propensity matching resulted in 239 pairs of HKT and IHT recipients with minimal differences in baseline characteristics. Heart–kidney recipients had higher 5- and 10-year survival than IHT recipients on unmatched (77% vs 69%, P = 0.011 and 58% vs 48%, P = 0.008) and propensity matched analyses (77% vs 68%, P = 0.026 and 57% vs 39%, P = 0.007). Heart–kidney transplantation was protective against 10-year mortality on multivariable regression (hazard ratio 0.585, P = 0.002). CONCLUSIONS In obese patients with non-dialysis-dependent kidney disease, HKT may decrease long-term mortality relative to IHT and should be strongly considered as a preferred treatment.

We aimed to identify a simple metric accounting for peri-procedural hemoglobin changes, independent of blood product transfusion strategies, and assess its correlation with outcomes in patients undergoing left ventricular assist device (LVAD) implantation We included consecutive patients undergoing LVAD implantation at a single center between 10/1/2008 and 6/1/2014. The anemia stress index (ASI), defined as the sum of number of packed red blood cells transfused and the hemoglobin changes after LVAD implantation, was calculated for each patient at 24 h, discharge, and 3 months after LVAD implantation. Our cohort included 166 patients (80.1% males, mean age 56.3 ± 15.6 years) followed up for a median of 12.3 months. Increases in ASI per unit were associated with a higher hazard for all-cause mortality and early RV failure. The associations between the ASI and all-cause mortality persisted after multivariable adjustment, irrespective of when it was calculated (adjusted HR of 1.11, 95% CI 1.03–1.20 per unit increase in ASI). Similarly, ASI at 24 h after implant was associated with early RV failure despite multivariable adjustment (OR 1.09, 95% CI 1.05–1.14). We present a novel metric, the ASI, that is correlated with an increased risk for all-cause mortality and early RV failure in LVAD recipients.

In October 2018, the United States implemented a change in the donor heart allocation policy from a three-tiered to a six-tiered status system. The purpose of the current study was to examine changes in waitlist patterns among patients listed for concomitant heart-liver transplantation with implementation of the new allocation system.Patients listed for heart-liver transplantation between January 1, 2012, and June 30, 2021, were identified from the United Network for Organ Sharing database. Patients were grouped by era according to initial list date before or after October 18, 2018. Competing risks regression for mortality, transplantation, removal from waitlist due to illness was performed according to the method of Fine and Gray. Waitlist data were censored at 3 years from initial listing.Overall, 523 patients were identified, of whom 310 were listed before (era 1, 59%) and 213 after (era 2, 41%) allocation change. Patients in era 1 were older, had more restrictive cardiomyopathy, and more preoperative inotrope use (all P.05). However, patients in era 2 has longer ischemic times (3.5 ± 1.1 vs 3.1 ± 1.1 hours, P.01) and more intraaortic balloon pump use (8.9% vs 3.9%, P = .016). Era 2 was associated with lower subdistribution hazard for death (hazard ratio 0.37; 95% CI, 0.13-1.02; P = .054) and increased transplantation (hazard ratio 1.35; 95% CI, 1.06-1.72; P = .015).The implementation of the US donor heart allocation policy was associated with more preoperative intraaortic balloon pump use for patients listed for heart-liver transplantation. Despite that, the modern era was associated with lower waitlist mortality and more frequent transplantation, without increased risk of delisting due to illness.

Cardiogenic shock represents a very challenging patient population due to the undifferentiated pathologies presenting as cardiogenic shock, difficult decision-making, prognostication, and ever-expanding support options. The role of cardiac surgeons on this team is evolving. The implementation of a shock team is associated with improved outcomes in patients with cardiogenic shock. Early deployment of mechanical circulatory support devices may allow an opportunity to rescue these patients. Cardiothoracic surgeons are a critical component of the shock team who can deploy timely mechanical support and surgical intervention in selected patients for optimal outcomes.

PURPOSE OF REVIEW There is a critical shortage of organs in cardiac transplantation. Recent advancements in both organ allocation and donor utilization have intended to address this shortage and optimally allocate allografts. This review evaluates several important aspects of recipient and donor management. For recipients, the focus is placed on the evolving mechanical circulatory support population and its bidirectional impact on organ allocation. From the donor standpoint, organ utilization is assessed with respect to increasing access to previously unused allografts. RECENT FINDINGS Implementation of the new heart allocation system in the United States has better stratified waitlist candidates by illness acuity. Compared to the prior system, those requiring venoarterial extracorporeal membrane oxygenation support are less likely to die on the waitlist, although conflicting data exists whether this has improved their posttransplant survival. The use of pretransplant intra-aortic balloon pumps has markedly increased, whereas transplantation of patients with dischargeable left ventricular assist devices has decreased. Although some studies have reported inferior short- to mid-term posttransplant survival in the new system compared to its predecessor, others report similar outcomes.Several recent advancements in donor utilization have also been noted. Coinciding with the global increase in drug overdose deaths, efforts have been made to increase use of these donors who are frequently considered 'increased risk' and are hepatitis C-positive. Grafts from these donors appear safe to use. These, alongside donation after circulatory death donors, represent potentially underutilized populations that may effectively expand the donor pool. SUMMARY Recent changes in organ allocation, alongside efforts to expand the donor pool, have attempted to improve cardiac allograft utilization and reduce the imbalance between organ supply and demand. Ongoing monitoring and continuous re-evaluation of these efforts will help guide future practice.

Extracellular vesicles (EV) that are derived from endothelial progenitor cells (EPC) have been determined to be a novel therapy for acute myocardial infarction, with a promise for immediate “off-the-shelf” delivery. Early experience suggests delivery of EVs from allogeneic sources is safe. Yet, clinical translation of this therapy requires assurances of both EV stability following cryopreservation and absence of an adverse immunologic response to EVs from allogeneic donors. Thus, more bioactivity studies on allogeneic EVs after cold storage are necessary to establish quality standards for its widespread clinical use. Thus, in this study, we aimed to demonstrate the safety and efficacy in delivering cryopreserved EVs in allogeneic recipients as a therapy for acute myocardial infarction. In this present study, we have analyzed the cardioprotective effects of allogeneic EPC-derived EVs after storage at −80°C for 2 months, using a shear-thinning gel (STG) as an in vivo delivery vehicle. EV size, proteome, and nucleic acid cargo were observed to remain steady through extended cryopreservation via nanoparticle tracking analysis, mass spectrometry, and nanodrop analysis, respectively. Fresh and previously frozen EVs in STG were delivered intramyocardially in a rat model of myocardial infarction (MI), with both showing improvements in contractility, angiogenesis, and scar thickness in comparison to phosphate-buffered saline (PBS) and STG controls at 4 weeks post-MI. Pathologic analyses and flow cytometry revealed minimal inflammatory and immune upregulation upon exposure of tissue to EVs pooled from allogeneic donor cells. Allogeneic EPC-EVs have been known to elicit minimal immune activity and retain therapeutic efficacy after at least 2 months of cryopreservation in a post-MI model.

The use of ventricular assist devices (VADs) as a bridge to heart transplant (HT) is increasing, while HT volume remains stagnant. This may portend longer waiting times and an otherwise more competitive environment for all patients on the HT waiting list. A retrospective analysis of patients who were listed for HT in the United Network for Organ Sharing (UNOS) database from 2000 to 2015 was conducted. Mean waiting time, proportion of HT reception (%HT), proportion of death (%death), and proportion of waiting list removal (%removal) were calculated across three eras: Era 1 (2000-2007), Era 2 (2008-2011), and Era 3 (2012-2015). During the study period, 29 728 patients successfully underwent HT. 19 127 (64.3%) were directly transplanted (direct HT); 4491 (15.1%) received VADs prior to listing as a bridge to decision (BTD); and 4593 (15.5%) received VADs after listing as a bridge to transplant (BTT). Across the three eras, the average number of registrants per year grew. Among all groups, waiting time increased across the eras. %HT generally decreased in the BTD and BTT groups but remained constant in the direct HT group. %removal increased, while %death decreased in all group across the eras. Waiting time for HT increased from 2000 to 2015. Patients with VADs as a bridge strategy experienced decreasing %HT and increasing %removal but stable survival. Improvements in VAD safety and durability will ensure their success as part of a bridge strategy to HT under the new UNOS allocation policy.

Purpose: We report on the clinical course and management of patients supported with durable implantable LVADs who developed outflow graft obstructions at a large academic center. Methods: We performed a retrospective review of patients receiving LVAD support from 2012 through 2020. Patients who developed an outflow graft obstruction diagnosed by computed tomography angiography (CTA) or angiogram were identified, and patient characteristics and outcomes were reported. Results: Of the 324 patients supported by LVAD at our institution, 11 patients (3.4%) were diagnosed with outflow graft obstructions. The most common presentation was low flow alarms, which was present in 10/11 patients, and the remaining patient presented with lightheadedness. Patients had minimal LDH elevation with 8/11 presenting with less than 2-fold the upper limit of normal. Transthoracic echocardiograms were not diagnostic, but CTA enabled non-invasive diagnoses in 8/11 of the patients. Three patients with extrinsic compression of the outflow graft successfully underwent endovascular stent placement, and three patients with outflow cannula kinks received supportive care. Of the five patients diagnosed with intraluminal thromboses, one received a heart transplant, one underwent an outflow graft revision, and three received supportive care due to comorbidities. Conclusion: Outflow graft obstructions remain a rare, but serious complication. The true prevalence of this entity is likely underestimated due to the non-specific clinical presentation. CTA is a pivotal non-invasive diagnostic step. Patients with external compression were successfully treated with endovascular stenting.

Whether to repair nonsevere tricuspid regurgitation (TR) during surgery for ischemic mitral valve regurgitation (IMR) remains uncertain.The goal of this study was to investigate the incidence, predictors, and clinical significance of TR progression and presence of ≥moderate TR after IMR surgery.Patients (n = 492) with untreated nonsevere TR within 2 prospectively randomized IMR trials were included. Key outcomes were TR progression (either progression by ≥2 grades, surgery for TR, or severe TR at 2 years) and presence of ≥moderate TR at 2 years.Patients' mean age was 66 ± 10 years (67% male), and TR distribution was 60% ≤trace, 31% mild, and 9% moderate. Among 2-year survivors, TR progression occurred in 20 (6%) of 325 patients. Baseline tricuspid annular diameter (TAD) was not predictive of TR progression. At 2 years, 37 (11%) of 323 patients had ≥moderate TR. Baseline TR grade, indexed TAD, and surgical ablation for atrial fibrillation were independent predictors of ≥moderate TR. However, TAD alone had poor discrimination (area under the curve, ≤0.65). Presence of ≥moderate TR at 2 years was higher in patients with MR recurrence (20% vs. 9%; p = 0.02) and a permanent pacemaker/defibrillator (19% vs. 9%; p = 0.01). Clinical event rates (composite of ≥1 New York Heart Association functional class increase, heart failure hospitalization, mitral valve surgery, and stroke) were higher in patients with TR progression (55% vs. 23%; p = 0.003) and ≥moderate TR at 2 years (38% vs. 22%; p = 0.04).After IMR surgery, progression of unrepaired nonsevere TR is uncommon. Baseline TAD is not predictive of TR progression and is poorly discriminative of ≥moderate TR at 2 years. TR progression and presence of ≥moderate TR are associated with clinical events. (Comparing the Effectiveness of a Mitral Valve Repair Procedure in Combination With Coronary Artery Bypass Grafting [CABG] Versus CABG Alone in People With Moderate Ischemic Mitral Regurgitation, NCT00806988; Comparing the Effectiveness of Repairing Versus Replacing the Heart's Mitral Valve in People With Severe Chronic Ischemic Mitral Regurgitation, NCT00807040).

Many single ventricle patients palliated with the Fontan operation suffer from Fontan failure and progressive liver disease. Combined heart-liver transplantation is a rarely utilized and complex transplant strategy available for select Fontan patients. At the Hospital of the University of Pennsylvania, all Fontan patients deemed eligible for a heart transplantation undergo a combined sequential dual organ transplantation with same-donor organs. This article describes the techniques utilized as well as current results.