Background: The frozen elephant trunk (FET) procedure remains an increasingly popular approach to address complex multi-segmental aortic pathologies, owing to their ability to promote false lumen thrombosis and reduce the need for second-stage operations. While the short-term outcomes of such procedures have been shown to be acceptable, much less is known regarding long-term outcomes. This systematic review evaluates long-term outcomes of the FET procedure.Methods: Studies with at least 12 months follow-up data on FETs were identified in four electronic databases. All studies were reviewed by two independent researchers and relevant data extracted. Long-term outcomes, including overall survival, freedom from reintervention, and freedom from aortic events, were evaluated using patient data recreated from digitized Kaplan-Meier curves.Results: Thirty-seven studies with 4,178 patients were identified. The majority of the studies focused solely on acute dissections. Average follow-up was 3.2 years. Overall survival at 1-, 3-, and 5-year was 89.6%, 85.2%, and 82.0%, respectively. Freedom from reintervention at the same timepoints were 93.9%, 89.3%, and 86.8%, respectively. Mortality, permanent neurological deficit and spinal cord injury were 10.2%, 7.7%, and 6.5%, respectively.Conclusions: Survival after the FET procedure is favorable, though ongoing close serial monitoring is essential to assess for the need for further reintervention. Larger multi-institutional registries are required to provide more robust evidence to better elucidate the patient cohort that would most benefit from the FET.

Background: Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the build-up of acidic metabolites results in decreased intracellular and extracellular pH that can reach as low as 6.0-6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly impacts cardiac function. Methods: We used genetic and pharmacological methods to investigate the role of acid sensing ion channel 1a (ASIC1a) in cardiac IRI at the cellular and whole organ level. Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as well as ex vivo and in vivo models of IRI were used to test the efficacy of ASIC1a inhibitors as pre- and post-conditioning therapeutic agents. Results: Analysis of human complex trait genetics indicate that variants in the ASIC1 genetic locus are significantly associated with cardiac and cerebrovascular ischemic injuries. Using hiPSC-CMs in vitro and murine ex vivo heart models, we demonstrate that genetic ablation of ASIC1a improves cardiomyocyte viability after acute IRI. Therapeutic blockade of ASIC1a using specific and potent pharmacological inhibitors recapitulates this cardioprotective effect. We used an in vivo model of myocardial infarction (MI) and two models of ex vivo donor heart procurement and storage as clinical models to show that ASIC1a inhibition improves post-IRI cardiac viability. Use of ASIC1a inhibitors as pre- or post-conditioning agents provided equivalent cardioprotection to benchmark drugs, including the sodium-hydrogen exchange inhibitor zoniporide. At the cellular and whole organ level, we show that acute exposure to ASIC1a inhibitors has no impact on cardiac ion channels regulating baseline electromechanical coupling and physiological performance. Conclusions: Collectively, our data provide compelling evidence for a novel pharmacological strategy involving ASIC1a blockade as a cardioprotective therapy to improve the viability of hearts subjected to IRI.

Heart transplantation from donation after circulatory death (DCD) donors has the potential to substantially increase overall heart transplant activity. The aim of this report is to review the first 8 y of our clinical heart transplant program at St Vincent’s Hospital Sydney, to describe how our program has evolved and to report the impact that changes to our retrieval protocols have had on posttransplant outcomes. Since 2014, we have performed 74 DCD heart transplants from DCD donors utilizing a direct procurement protocol followed by normothermic machine perfusion. Changes to our retrieval protocol have resulted in a higher retrieval rate from DCD donors and fewer rejections of DCD hearts during normothermic machine perfusion. Compared with our previously reported early experience in the first 23 transplants, we have observed a significant reduction in the incidence of severe primary graft dysfunction from 35% (8/23) to 8% (4/51) in the subsequent 51 transplant recipients (P < 0.01). The only withdrawal time interval significantly associated with severe primary graft dysfunction was the asystolic warm ischemic time: 15 (12–17) versus 13 (11–14) min (P < 0.05). One- and 5-y survival of DCD heart transplant recipients was 94% and 88%, comparable to that of a contemporary cohort of donation after brain death recipients: 87 and 81% (P-value was not significant). In conclusion, heart transplantation from DCD donors has become a major contributor to our overall transplant activity accounting for almost 30% of all transplants performed by our program in the last 2 y, with similar DCD and donation after brain death outcomes.

Background: Frailty is prevalent in patients with heart failure (HF) and associated with increased morbidity and mortality. Hence, there has been increased interest in the reversibility of frailty following treatment with medication or surgery. This systematic review aimed to assess the reversibility of frailty in patients with HF before and after surgical interventions aimed at treating the underlying cause of HF. It also aimed to assess the efficacy of cardiac rehabilitation and prehabilitation in reversing or preventing frailty in patients with HF. Methods and Results:Searches of PubMed, MEDLINE and Academic Search Ultimate identified studies with HF patients undergoing interventions to reverse frailty. Titles, abstracts and full texts were screened for eligibility based on the PRISMA guidelines and using predefined inclusion/exclusion criteria in relation to participants, intervention, control, outcome and study design. In total, 14 studies were included: 3 assessed the effect of surgery, 7 assessed the effect of rehabilitation programs, 2 assessed the effect of a prehabilitation program and 2 assessed the effect of program interruptions on HF patients.Conclusions: Overall, it was found that frailty is at least partially reversible and potentially preventable in patients with HF. Interruption of rehabilitation programs resulted in deterioration of the frailty status. Future research should focus on the role of prehabilitation in mitigating frailty prior to surgical intervention.

Purpose of Review Recent advances in donor heart preservation have allowed the utilization of hearts that would typically be discarded due to prolonged ischemic times or donation via the circulatory death pathway. This review will discuss recent advances in donor heart preservation including optimization of machine perfusion technologies and future strategies of potential benefit for the donor heart and transplant outcomes. Recent Findings Improvements in organ preservation strategies have enabled retrieval of donor hearts that were not ideal for static cold storage. Machine perfusion (normothermic and hypothermic) and normothermic regional perfusion have ultimately expanded the donor pool for adult heart transplantation. Xenotransplantation has also incorporated machine perfusion for porcine donor heart preservation. Summary Traditional static cold storage is feasible for non-complex donors and transplants. Machine perfusion has enabled increased donor heart utilization however optimal preservation strategies are dependent on the donor criteria, predicted ischemic times and surgical complexity.

OBJECTIVES Right ventricular failure after left ventricular assist device (LVAD) insertion is associated with significant mortality and morbidity. Mechanical support options include right ventricular assist devices, venoarterial extracorporeal membrane oxygenation (ECMO) and venopulmonary artery ECMO, the latter often involving central cannulation. We sought to evaluate the feasibility and early outcomes of a truly percutaneous venopulmonary artery (pVPA) ECMO strategy, with the potential advantage of bedside removal once weaned. METHODS Data from a single tertiary centre were reviewed retrospectively from January 2014 to January 2019. During this time, 54 patients underwent LVAD insertion, with 19 requiring mechanical support for right ventricular failure. Among them, 10 patients received pVPA ECMO. Implantation of the pVPA ECMO was performed under transoesophageal echocardiography and fluoroscopy guidance, with an inflow cannula placed in the right atrium via the right femoral vein and an outflow cannula placed in the left pulmonary artery (PA) via the right internal jugular vein. RESULTS Cannula insertion was 100% successful with no need for repositioning. Eight patients (80%) were able to be successfully weaned (at the bedside); 6 were discharged from the hospital and there were no cases of early sepsis, mediastinitis or thromboembolism. At follow-up, 5 patients had received transplants (50%), with 1 on LVAD support as destination therapy (10%). Survival was 60 ± 15% and 50 ± 16% at 6 and 12 months, respectively. CONCLUSIONS pVPA ECMO is 100% technically feasible and is an efficient method for temporary right ventricular support after LVAD insertion with the advantage of simple bedside removal and avoidance of a PA graft remnant in the chest cavity.

BackgroundAcute renal failure (ARF) is the most common major complication following cardiac surgery for acute aortic syndrome (AAS) and worsens the postoperative prognosis. Our aim was to establish a machine learning prediction model for ARF occurrence in AAS patients.MethodsWe included AAS patient data from nine medical centers (n = 1,637) and analyzed the incidence of ARF and the risk factors for postoperative ARF. We used data from six medical centers to compare the performance of four machine learning models and performed internal validation to identify AAS patients who developed postoperative ARF. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to compare the performance of the predictive models. We compared the performance of the optimal machine learning prediction model with that of traditional prediction models. Data from three medical centers were used for external validation.ResultsThe eXtreme Gradient Boosting (XGBoost) algorithm performed best in the internal validation process (AUC = 0.82), which was better than both the logistic regression (LR) prediction model (AUC = 0.77, p &lt; 0.001) and the traditional scoring systems. Upon external validation, the XGBoost prediction model (AUC =0.81) also performed better than both the LR prediction model (AUC = 0.75, p = 0.03) and the traditional scoring systems. We created an online application based on the XGBoost prediction model.ConclusionsWe have developed a machine learning model that has better predictive performance than traditional LR prediction models as well as other existing risk scoring systems for postoperative ARF. This model can be utilized to provide early warnings when high-risk patients are found, enabling clinicians to take prompt measures.

Multiple AV reoperations carry an acceptable risk of early postoperative mortality, particularly for isolated valve replacements of SVD.