Single-center experience of extended brain-death donor heart preservation with the organ care system.

BACKGROUND: The Organ Care System (OCS) (Transmedics, Andover, MA) reduces cold ischemic time of donor hearts by producing a normothermic beating state during ex vivo perfusion, enabling extended ex situ intervals, which potentially increases donor pool. We aimed to compare outcomes in utilization of OCS and conventional cold storage technique. METHODS: Consecutive heart transplants following brain death at our institution between May 2022 and July 2023 were analyzed. Recipients were divided into those receiving hearts preserved with OCS [N = 15] and those with conventional cold storage (Control, N = 27), with OCS utilization when anticipated ischemic time was more than 4 h. Pre-transplant characteristics and transplant outcomes were compared. RESULTS: OCS utilization allowed a significant increase in distance traveled for heart retrieval (OCS, 624 ± 269 vs. Control, 153 ± 128 miles, p < 0.001), with longer mean total preservation times (6.2 ± 1.1 vs 2.6 ± 0.6 h, p < 0.001). All but one patient displayed a general decrease or plateau in lactate throughout perfusion time by OCS. Both groups experienced similar rates of severe primary graft dysfunction (OCS, 6.7% [N = 1] vs. Control, 11.1% [N = 3], p = 0.63), with 100% in-hospital survival in the OCS group compared to 96.3% in the Control group (p = 0.34). Kaplan-Meier survival analysis showed that estimated one-year survival were comparable (OCS, 93.3 ± 6.4% vs. Control, 88.9 ± 6.0%, p = 0.61). CONCLUSION: With a mean preservation time of around 6 h and distance covered of over 600 miles, our results using OCS indicate a potential to safely increase the quantity and viability of accessible organs, thus broadening the donor pool without negatively affecting outcomes.

Outpatient Continuous Intravenous Inotropy in the Modern Era.

The use of continuous inotropy in patients with advanced heart failure (HF) has been historically controversial due to the prevailing notion that it will increase mortality. In practice, clinicians have continued to revisit this idea as there remains a lack of treatment options for patients in stage D HF. Clinical trials in the past have generally not shown favorable effects of long-term chronic infusions of positive IV inotropic agents on symptoms and exercise tolerance. However, these older studies which indicated poor outcomes with palliative inotropes may not apply to current practice. Modern trials and case series have shown that milrinone and dobutamine may be safely used in patients who are bridging to device therapy or transplant or for palliation. Broad adoption of mortality-reducing modern guideline-directed medical therapy and implantable cardioverter defibrillators may have contributed to the positive results that contemporary trials have seen with inotrope use. For the stage D HF patient, modern use of outpatient inotropy (OI) can alleviate symptom burden and prolong time spent at home. Additionally, more recent studies and case series suggest that OI can be a reasonable alternative to left ventricular assist device placement for both bridging to transplant or as destination therapy. In the appropriate patient, and according to the patient's informed decision and preference, this may be a viable alternative therapeutic option. Contemporary data suggest that OI should be considered in patients who are being evaluated for advanced therapies.

Cardiac Allograft Rejection: Strategies for Success in the Face of Immune Challenges.

Heart transplantation for patients with end-stage heart failure refractory to medical therapy has remained definitive treatment with significant advances in posttransplant care. Despite improvement in postoperative morbidity and mortality, acute cellular rejection (ACR) and antibody-mediated rejection (AMR) remain substantial challenges that can lead to allograft failure and patient mortality. Immunosuppressive agents have been the mainstay of both prevention and treatment for ACR and AMR; however, many challenges exist with traditional therapies. There are a multitude of molecular pathways involved in mediating the humoral and cellular response to rejection, offering various targets for treatment. This review summarizes therapies used in the management of ACR and AMR as extrapolated from use in induction therapy and treatment of other solid-organ transplant rejection. Future studies focused on cardiac transplant recipients are needed to expand therapeutic options.

Evolution of concomitant use of veno-arterial extracorporeal membrane oxygenation support with Impella in cardiogenic shock: From percutaneous femoral Impella to axillary Impella 5.5.

BACKGROUND: Little is known about safety and efficacy of the use of Impella 5.5 compared to previous iterations in the setting of Impella with Veno-Arterial Extracorporeal Membrane Oxygenation Support as ECPELLA. METHODS: Consecutive patients who were treated by ECPELLA with surgically implanted axillary Impella 5.5 (N = 13) were compared with patients supported by ECPELLA with percutaneous femoral Impella CP or 2.5 (Control, N = 13). RESULTS: The total ECPELLA flow was higher in ECPELLA 5.5 group (6.9 vs. 5.4 L/min, p = 0.019). Actual hospital survival was higher than predicted and comparable in both groups (ECPELLA 5.5, 61.5% vs. Control, 53.8%, p = 0.691). Both total device complications (ECPELLA 5.5, 7.7% vs. Control, 46.1%, p = 0.021) and Impella-specific complications (ECPELLA 5.5, 0% vs. Control, 30.8%, p = 0.012) were significantly lower in the ECPELLA 5.5 group. CONCLUSIONS: Utilization of Impella 5.5 in the setting of ECPELLA provides greater hemodynamic support with a lower risk of complications compared to Impella CP or 2.5.

Ex Vivo Heart Perfusion for Cardiac Transplantation Allowing for Prolonged Perfusion Time and Extension of Distance Traveled for Procurement of Donor Hearts: An Initial Experience in the United States.

Scarcity of donor hearts continues to be a challenge for heart transplantation (HT). The recently Food and Drug Administration-approved Organ Care System (OCS; Heart, TransMedics) for ex vivo organ perfusion enables extension of ex situ intervals and thus may expand the donor pool. Because postapproval real-world outcomes of OCS in HT are lacking, we report our initial experience. Methods: We retrospectively reviewed consecutive patients who received HT at our institution in the post-Food and Drug Administration approval period from May 1 to October 15, 2022. Patients were divided into 2 groups: OCS versus conventional technique. Baseline characteristics and outcomes were compared. Results: A total of 21 patients received HT during this period, 8 using OCS and 13 conventional techniques. All hearts were from donation after brain death donors. The indication for OCS was an expected ischemic time of >4 h. Baseline characteristics in the 2 groups were comparable. The mean distance traveled for heart recovery was significantly higher in the OCS group (OCS, 845 ± 337, versus conventional, 186 ± 188 mi; P < 0.001), as was the mean total preservation time (6.5 ± 0.7 versus 2.5 ± 0.7 h; P < 0.001). The mean OCS time was 5.1 ± 0.7 h. In-hospital survival in the OCS group was 100% compared with 92.3% in the conventional group (P = 0.32). Primary graft dysfunction was similar in both groups (OCS 12.5% versus conventional 15.4%; P = 0.85). No patient in the OCS group required venoarterial extracorporeal membrane oxygenation support after transplant compared with 1 in the conventional group (0% versus 7.7%; P = 0.32). The mean intensive care unit length of stay after transplant was comparable. Conclusions: OCS allowed utilization of donors from extended distances that otherwise would not be considered because ischemic time would be prohibitive by conventional technique.

Simple technique of distal leg perfusion during heart transplant in patients with preoperative veno-arterial extracorporeal membrane oxygenation support.

Direct heart transplant from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is challenging. Continuation of postoperative VA-ECMO support may be required in the setting of primary graft dysfunction or severe vasoplegia. We describe a simple technique to perfuse the ipsilateral leg of an arterial ECMO cannula during heart transplant while the ECMO circuit is turned off but maintaining the arterial cannula and distal perfusion catheter in place. This technique minimizes the number of intraoperative procedures with a minimal risk of leg ischemia, and provides a smooth transition to postoperative VA-ECMO support if necessary.

Cannulation-related adverse events of peripheral veno-arterial extracorporeal membrane oxygenation support in heart transplantation: Axillary versus femoral artery cannulation.

BACKGROUND: In heart transplantation (HT), peripheral veno-arterial extracorporeal membranous oxygenation (VA-ECMO) is utilized preoperatively as a direct bridge to HT or postoperatively for primary graft dysfunction (PGD). Little is known about wound complications of an arterial VA-ECMO cannulation site which can be fatal. METHODS: From 2009 to 2021, outcomes of 80 HT recipients who were supported with peripheral VA-ECMO either preoperatively or postoperatively were compared based on the site of arterial cannulation: axillary (AX: N = 49) versus femoral artery (FA: N = 31). RESULTS: Patients in the AX group were older (AX: 59 years vs. 52 years, p = .006), and less likely to have extracorporeal cardiopulmonary resuscitation (0% vs. 12.9%, p = .040). Survival to discharge (AX, 81.6% vs. FA. 90.3%, p = .460), incidence of stroke (10.2% vs. 6.5%, p = .863), VA-ECMO cannulation-related bleeding (6.1% vs. 12.9%, p = .522), and arm or limb ischemia (0% vs. 3.2%, p = .816) were comparable. ECMO cannulation-related wound complications were lower in the AX group (AX, 4.1% vs. FA, 45.2%, p < .001) including the wound infections (2.0% vs. 32.3%, p < .001). In FA group, all organisms were gram-negative species. In univariate logistic regression analysis, AX cannulation was associated with less ECMO cannulation-related wound complications (Odds ratio, .23, p < .001). There was no difference between cutdown and percutaneous FA insertion regarding cannulation-related complications. CONCLUSIONS: Given the lower rate of wound complications and comparable hospital outcomes with femoral cannulation, axillary VA-ECMO may be an excellent option in HT candidates or recipients when possible.

Ecpella 5.5: An Evolution in the Management of Mechanical Circulatory Support.

There are several endovascular options for temporary mechanical circulatory support in patients with refractory cardiogenic shock. These devices are often utilized in tandem to provide maximal support, including the combination of venoarterial extracorporeal membrane oxygenation with the Impella device, termed ECPELLA. An underappreciated characteristic of mechanical circulatory support is whether they provide cardiac "replacement" and/or cardiac "assistance." Within this framework, we propose an evolution in the approach to ECPELLA utilizing the Impella 5.5, with a focus on the Impella 5.5 as the primary support device.

High flow from Impella 5.5 with partial veno-arterial extracorporeal membrane oxygenation support: Case series.

Optimal flow balance between Impella 5.5 and veno-arterial extracorporeal membrane oxygenation (ECMO) support in the setting of EC-PELLA (ECMO+Impella) is unknown. Outcomes of high Impella 5.5 flow in the setting of EC-PELLA support were reviewed (N = 7). EC-PELLA was successfully explanted in 6 patients (bridge-to-transplant, N = 1; bridge-to-recovery, N = 5). The median duration of EC-PELLA support in explanted patients was 6 days. Survival at discharge was 71.4% (5 patients). In terms of device-related events, either VA-ECMO or Impella-related complications were not experienced. The median performance level of Impella 5.5 was P5 at the time of starting EC-PELLA support and then increased with time up to the median of P8 with increment of the Impella flow, and index (L/min/m2 ). The percentage of Impella flow per total EC- PELLA flow reached 50% after 48 h of support. The vasoactive-inotropic score and serum lactate level improved after institution of EC-PELLA support as well as the pulmonary artery pressures and central venous pressure. In conclusion, a high pump flow from Impella 5.5 with partial VA-ECMO support in the setting of EC-PELLA provided great support with favorable survival and device-related complications rate.

Role of MicroRNA in Heart Transplant.

The need for noninvasive biomarkers for diagnostic, prognostic, and therapeutic purposes is increasingly being recognized in the field of heart transplantation. MicroRNAs are a class of novel biomarkers that control gene expression and influence cellular functions, including differentiation, proliferation, and functional regulation of the immune system. They can be detected in the serum, plasma, and urine and may serve as early noninvasive biomarkers for various disease processes. Despite significant advances in heart transplantation, challenges remain in the short and long term with early graft injury and dysfunction, both cellular and antibody-mediated rejection, infections of varying types and severity, and cardiac allograft vasculopathy, which require an interventional approach for diagnosis and management. In this article, we review the current knowledge on the role of microRNAs in heart transplantation and its related complications and discuss their potential impact in future strategies to manage heart transplantation.

Survival With Continuous Outpatient Intravenous Inotrope Therapy in the Modern Era.

BACKGROUND: To describe baseline characteristics and outcomes in the largest known registry of advanced heart failure (HF) patients receiving continuous outpatient intravenous inotrope therapy. Studies evaluating the use of outpatient inotropes for palliation or as a bridge to advanced therapies were performed before current guideline directed medical and device therapy (GDMDT). There are limited data on the modern experience using outpatient inotrope (OI) therapy. STUDY QUESTION: We aimed to study current use and outcomes of OI. STUDY DESIGN: Retrospective database analysis. MEASURES AND OUTCOMES: From 2015 to 2017, 1540 advanced HF patients in a largess nationwide registry received OI with either milrinone or dobutamine. Baseline characteristics of 1149 patients data were retrospectively reviewed. Unadjusted Kaplan-Meier survival estimates censored at the time of transplant or mechanical circulatory support were reported. RESULTS: Of 1149 patients, more patients were treated with milrinone than dobutamine (64.6% vs. 35.4%). Regardless of the indication for OI, estimated 1 and 2-years survival was 61.8% and 41.6%, respectively. Milrinone use was associated with a greater 1-year survival than dobutamine (70.7% vs. 46.2%, P < 0.0001). The superiority of milrinone over dobutamine extended to all indications for OI, including bridge to transplant (85.9% vs. 71.3%, P < 0.0001), bridge to mechanical support (91.4% vs. 71%, P = 0.001), and palliation (73.6% vs. 63.3%, P < 0.001). After adjusting for indication, age, gender and weight, milrinone was associated with lower mortality than dobutamine (HR 0.50, 95% CI 0.39-0.64, P < 0.0001). CONCLUSIONS: In the largest dataset of HF patients receiving OI, survival on OI for palliation in the current era of GDMDT is significantly higher than previously reported. Compared with dobutamine, milrinone was associated with improved survival in all cohorts.

Mineralocorticoid Receptor Antagonist Use in Heart Failure With Reduced Ejection Fraction and End-Stage Renal Disease Patients on Dialysis: A Literature Review.

Mineralocorticoid receptor antagonists (MRAs) are known to have a proven mortality benefit in heart failure with reduced ejection fraction (HFrEF) without kidney disease. As patients with end-stage renal disease (ESRD) requiring either peritoneal dialysis or hemodialysis were excluded in clinical trials of HFrEF, the data are scant on the appropriate use of MRAs in this population. The unknown efficacy, along with concerns of adverse effects such as hyperkalemia, has limited the willingness of clinicians to consider using MRAs in these patients. However, it is unclear whether the risk of hyperkalemia is present if a patient is oliguric or anuric. Current guidelines recommend against the use of MRAs in patients with chronic kidney disease, but do not address the use of MRAs in patients requiring dialysis. This article will review the epidemiology of heart failure in ESRD, the pathophysiological derangements of the renin-angiotensin-aldosterone system in patients with kidney disease, and the results from case series and trials of the use of MRAs in ESRD with HFrEF. Although limited to several small trials using MRAs in peritoneal and hemodialysis patients with or without HFrEF, the current literature appears to show the potential for clinical benefits with little risk.

Peripartum Cardiomyopathy Incidence, Risk Factors, Diagnostic Criteria, Pathophysiology, and Treatment Options.

Peripartum cardiomyopathy is a rare and a severe form of heart failure that affects women during pregnancy or shortly after delivery. Risk factors include advanced age, race, multiparity, multifetal pregnancy, socioeconomic disparity, and medical comorbidities including systemic hypertension, diabetes, asthma, and anemia. Peripartum cardiomyopathy is associated with increased morbidity and mortality, as well as a detrimental long-term impact on quality of life. Its etiology is not clear, although it is thought to be a combined effect of a hyperdynamic fluid state associated with pregnancy, hormonal changes unique to gestation, and a genetic predisposition. There is no current expert consensus on an optimal treatment regimen. This article will provide a comprehensive review and update on this important disease state.

Use of levosimendan in acute and advanced heart failure: short review on available real-world data.

Published data have shown potential advantages of levosimendan in the management of acute decompensated heart failure and advanced heart failure when standard medical therapies threaten hemodynamics and organ perfusion are unable to alleviate clinical symptoms. Levosimendan distinguishes itself from other catecholaminergic inotropes by its three mechanisms of action: positive inotropy, vasodilation, and cardioprotection. In addition, its pharmacokinetics allow for a longer duration of action from the metabolite OR1896 allowing for further cardiovascular therapeutic effects for several days, even after discontinuation of the parent drug.

Advanced Heart Failure Management and Transplantation.

Hypertrophic cardiomyopathy is a genetic heart disease with heterogeneous clinical features, including progression to advanced heart failure. The development of these symptoms can be related to outflow obstruction but in some patients reflects an underlying process of fibrosis and progressive ventricular dysfunction. For patients with end-stage disease, traditional heart failure therapies have not proved beneficial. As such, more advanced therapies, such as left ventricular assist device or cardiac transplantation, should be considered for these patients. Although left ventricular assist device support is used infrequently due to the restrictive physiology underlying hypertrophic cardiomyopathy, transplant represents an effective treatment, with encouraging long-term outcome data.

Diagnosis, Treatment, and Management of Orthotopic Liver Transplant Candidates With Portopulmonary Hypertension.

Portopulmonary hypertension (POPH) is seen in 5-8% of orthotopic liver transplantation (OLT) candidates and has significant implications for clinical outcomes. POPH is characterized by vasoconstriction and remodeling of the pulmonary vasculature. It is exacerbated by the hyperdynamic circulation that is common in advanced liver disease. Screening all OLT candidates with transthoracic echocardiography to assess pulmonary pressures and right ventricular function is crucial, as clinical symptoms alone are not reliable. Any significant right ventricular dysfunction or dilatation along with an elevation in estimated pulmonary pressures usually triggers further investigation with right heart catheterization. The mainstays of therapy of POPH are vasodilators that are used in pulmonary arterial hypertension. They include monotherapy or combination therapy with prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors/guanylate cyclase stimulator. Limited evidence from smaller studies and case series suggests that a timely diagnosis of POPH and the early initiation of treatment improve patient outcomes, whether or not OLT is ultimately undertaken. Given the historically high perioperative mortality rate of more than 35%, POPH remains a contraindication to OLT unless it is treated and responsive to vasodilator therapy. We review the current literature and International Liver Transplant Society practice guidelines (2016) for the latest in understanding POPH, its pathogenesis, diagnosis, modern pharmacological treatment, indications, and contraindications for OLT, as well as perioperative management.

Management of pulmonary hypertension from left heart disease in candidates for orthotopic heart transplantation.

Pulmonary hypertension in left heart disease (PH-LHD) commonly complicates prolonged heart failure (HF). When advanced, the PH becomes fixed or out of proportion and is associated with increased morbidity and mortality in patients undergoing orthotopic heart transplant (OHT). To date, the only recommended treatment of out of proportion PH is the treatment of the underlying HF by reducing the pulmonary capillary wedge pressure (PCWP) with medications and often along with use of mechanical circulatory support. Medical therapies typically used in the treatment of World Health Organization (WHO) group 1 pulmonary arterial hypertension (PAH) have been employed off-label in the setting of PH-LHD with varying efficacy and often negative outcomes. We will discuss the current standard of care including treating HF and use of mechanical circulatory support. In addition, we will review the studies published to date assessing the efficacy and safety of PAH medications in patients with PH-LHD being considered for OHT.

Left Ventricular Assist Device in Older Adults.

Left ventricular assist devices (LVADs) are an effective therapy for a growing and aging population in the background of limited donor supply. Selecting the proper patient involves assessment of indications, risk factors, scores for overall outcomes, assessment for right ventricular failure, and optimal timing of implantation. LVAD complications have a 5% to 10% perioperative mortality and complications of bleeding, thrombosis, stroke, infection, right ventricular failure, and device failure. As LVAD engineering technology evolves, so will the risk-prediction scores. Hence, more large-scale prospective data from multicenters will continually be required to aid in patient selection, reduce complications, and improve long-term outcomes.