ASAIO Journal最新文献

Accurate activity classification is essential for the advancement of closed-loop control for left ventricular assist devices (LVADs), as it provides necessary feedback to adapt device operation to the patient's current state. Therefore, this study aims at using deep neural networks (DNNs) to precisely classify activity for these patients. Recordings from 13 LVAD patients were analyzed, including heart rate, LVAD flow, and accelerometer data, classifying activities into six states: active, inactive, lying, sitting, standing, and walking. Both binary and multiclass classifiers have been trained to distinguish between active and inactive states and to discriminate the remaining categories. The models were refined by testing several architectures, including recurrent and convolutional layers, optimized via hyperparameter search. Results demonstrate that integrating LVAD flow, heart rate, and accelerometer data leads to the highest accuracy in both binary and multiclass classification. The optimal architectures featured two and three bidirectional long short-term memory layers for binary and multiclass classifications, respectively, achieving accuracies of 91% and 84%. In this study, the potential of DNNs has been proven for providing a robust method for activity classification that is vital for the effective closed-loop control of medical devices in cardiac care.

Calcium channel blocker (CCB) toxicity presents a significant mortality risk, highlighting the need for effective treatment strategies such as extracorporeal membrane oxygenation (ECMO). This study analyzes Extracorporeal Life Support Organization (ELSO) registry data to determine the mortality rate in adults treated with ECMO for CCB toxicity and identifies clinical predictors of mortality. A retrospective analysis of the ELSO registry from January 2016 to April 2023 was conducted, focusing on adults diagnosed with CCB toxicity (ICD-10 T46.1) who received ECMO. Data collected included patient demographics, ECMO details (mode, duration, type), pre-ECMO clinical indicators (pH, lactate levels, cardiac arrest incidence), and in-hospital mortality. The analysis employed descriptive statistics to profile the patient population, with independent t-tests and chi-square tests comparing survivors to nonsurvivors. Logistic regression identified mortality predictors, integrating multiple imputations to remedy missing data, thus ensuring the analysis's integrity. The mortality rate for ECMO-treated CCB toxicity was 40.6%. Severe acidosis and the need for pre-ECMO renal replacement therapy were identified as key predictors of mortality. Further research is needed to determine if early ECMO initiation before a significant pH drop improves outcomes.

Advancements in left ventricular assist device (LVAD) technologies have significantly lowered morbidity and mortality in patients with end-stage heart disease; however, they still carry significant risks. Though infrequent, intraabdominal injury during driveline tunneling can be catastrophic. Laparoscopic visualization can reduce these risks, especially benefiting patients with lower body mass indexes and thin abdominal walls. We present two cases of laparoscopic driveline tunneling. The laparoscopic procedure begins poststernotomy and preheparin administration to mitigate bleeding risks. Supraumbilical port placement is performed for optimal direct visualization of the abdominal space for accurate driveline tunneling. It involves careful management of insufflation pressure to prevent hemodynamic collapse by restricting venous return. This approach ensures that the driveline is positioned correctly without injury to any intraabdominal structures.

Mechanical circulatory support (MCS) as a bridge to lung transplant is an infrequent but accepted pathway in patients who have refractory end-stage pulmonary failure. The American Association of Thoracic Surgeons Expert Consensus Guidelines, published in 2023, recommends venovenous (VV) extracorporeal membrane oxygenation (ECMO) as the initial configuration for those patients who have failed conventional medical therapy, including mechanical ventilation, while waiting for lung transplantation and needing MCS. Alternatively, venoarterial (VA) ECMO can be used in patients with acute right ventricular failure, hemodynamic instability, or refractory respiratory failure. With the advancement in percutaneous venopulmonary (VP) ECMO cannulation techniques, this option is becoming an attractive configuration as bridge to lung transplantation. This configuration enhances stability of the right ventricle, prevents recirculation with direct introduction of pulmonary artery oxygenation, and promotes hemodynamic stability during mobility, rehabilitation, and sedation-weaning trials before lung transplantation. Here, we present a case series of eight percutaneous VP ECMO as bridge to lung transplant with all patients mobilized, awake, and successfully transplanted with survival to hospital discharge.

Oxidative stress occurs during ex-situ heart perfusion (ESHP) and may negatively affect functional preservation of the heart. We sought to assess the status of key antioxidant enzymes during ESHP, and the effects of augmenting these antioxidants on the attenuation of oxidative stress and improvement of myocardial and endothelial preservation in ESHP. Porcine hearts were perfused for 6 hours with oxygen-derived free-radical scavengers polyethylene glycol (PEG)-catalase or PEG-superoxide dismutase (SOD) or with naive perfusate (control). The oxidative stress-related modifications were determined in the myocardium and coronary vasculature, and contractile function, injury, and endothelial integrity were compared between the groups. The activity of key antioxidant enzymes decreased and adding catalase and SOD restored the enzyme activity. Cardiac function and endothelial integrity were preserved better with restored catalase activity. Catalase and SOD both decreased myocardial injury and catalase reduced ROS production and oxidative modification of proteins in the myocardium and coronary vasculature. The activity of antioxidant enzymes decrease in ESHP. Catalase may improve the preservation of cardiac function and endothelial integrity during ESHP. While catalase and SOD may both exert cardioprotective effects, unbalanced SOD and catalase activity may paradoxically increase the production of reactive species during ESHP.