Artificial organs最新文献

Introduction: A substantial proportion of patients receiving left ventricular assist devices (LVADs) present with pre-existing atrial fibrillation (AF). However, the prognostic significance of AF-particularly regarding overall survival and ventricular arrhythmias (VAs)-remains unclear.

Methods: Patients included were those from the multicenter ASSIST-ICD observational study. The association between AF and the primary endpoint of all-cause mortality was evaluated using a 1:1 propensity score-matched cohort. Secondary outcomes included cardiovascular and non-cardiac mortality, bleeding, stroke, pump thrombosis, and the occurrence of early (≤ 30 days post-implant) and late VAs.

Results: Among 652 LVAD recipients, 286 patients (43.9%) had a history of AF before LVAD implantation, with a median follow-up of 9.1 months (2.5-22.1). AF patients were older, with higher rates of dilated cardiomyopathy, a history of VAs, and longer heart failure duration. After matching, AF was not associated with higher mortality (HR 0.93 [0.69-1.26]). AF subtype (paroxysmal, persistent, permanent) had no impact on mortality. There were no significant differences in cardiovascular/non-cardiac mortality, bleeding, ischemic stroke, pump thrombosis, or early VAs. However, AF was linked to a higher incidence of late VAs.

Conclusion: In this large multicenter study, AF before LVAD implantation was not associated with increased risks of mortality, bleeding, stroke, or pump thrombosis, but was linked to a higher incidence of late VAs. These findings, based on earlier-generation devices, should be interpreted cautiously given the recent adoption of the HeartMate 3, offering improved hemocompatibility. Further studies are needed to identify LVAD patients where AF carries clinical significance and guide optimal management.

Background: Myofascial pain syndrome (MPS) originates from myofascial trigger points (MTPs)- hypersensitive nodules commonly found in the trapezius muscle (TM) that cause pain and functional limitations. While transcutaneous electrical nerve stimulation (TENS) is a conventional treatment, a novel approach combining electrical muscle stimulation (EMS) with active stretching (AS) has recently been developed (EMS + AS).

Methods: EMS electrodes were placed transversely across muscle fibers to induce localized contractions and thus greater stretch of MTP-containing regions compared to AS alone. EMS plays a role similar to a therapist's hand in passive stretching in that it provides resistance force. Forty-one participants with MTPs in the TM received single sessions of EMS + AS, sham stimulation (SS) + AS, and TENS. Each session included three 10-s stimulations with 10-s rest intervals. Pain intensity (PI), pressure pain threshold (PPT), and surface electromyography (sEMG) for maximal voluntary contraction (%MVC) amplitude analysis of TM function improvement were the three outcome measures used to assess treatment effectiveness. To evaluate the immediate effects of short-duration treatments with EMS + AS compared to SS + AS and TENS. All three treatments were applied in a randomized order.

Results: EMS + AS showed significant improvements in PI and PPT (t₍₄₀₎ = -6.01 and t₍₄₀₎ = 5.38, p < 0.001, respectively). EMS + AS showed a small sEMG activity during TM function improvement of 0.49 ± 0.056 %MVC at post-treatment, normalized to pre-treatment values. Compared to SS + AS and TENS, EMS + AS significantly increased PPT changes (F_(2,120) = 13.442, p < 0.001); however, there were no significant differences in PI or mean %MVC.

Conclusions: This study demonstrates that EMS generates a local contraction instead of a full contraction for a muscle. EMS's effect is related to the aim of mimicking passive stretching performed by the therapist's hand. Ultimately, EMS + AS has the potential to be an effective approach for alleviating MPS symptoms.

Background: Normothermic machine perfusion (NMP) is increasingly used to assess liver grafts before transplantation. While viability assessment of the hepatocellular compartment has been widely adopted, viability assessment of the biliary compartment remains controversial due to the lack of reliable markers. Glutathione (GSH) plays a key role in bile formation and may serve as a marker for biliary viability. Thus, the present study aimed to investigate the suitability of GSH as a potential marker for biliary viability assessment during NMP.

Methods: Between 2018 and 2021, livers undergoing NMP were included in the study. Bile samples were collected at 1 h, 6 h, and at the end of NMP, and then analyzed using enzyme-linked immunosorbent assay (ELISA). Results were correlated with perfusion parameters and clinical outcomes.

Results: 56 livers underwent NMP during the study period, of which 41 were successfully transplanted (73.2%). Within 1 year after transplantation, 19 patients (46.3%) developed biliary complications. 1-year patient survival was 80.5% and 1-year graft survival (death-censored) was 94.6%. The GSH in transplanted livers showed a significant increase over time (Hour 1: 25.9 ± 31.2 μM vs. End: 108.7 ± 95.3 μM, p < 0.001) and significant inverse correlation with the occurrence of biliary complications after transplantation (p < 0.05). GSH concentration at the first hour measurement was significantly lower in livers that were deemed non-transplantable (11.2 μM vs. 25.9 μM, p = 0.006).

Conclusions: Our data show an increase of GSH in bile during liver ex situ NMP. We found a negative correlation between GSH concentration and the development of biliary complications, suggesting GSH as a new marker for biliary viability assessment.

Background: Patients undergoing hemodialysis (HD) face a significantly elevated risk of cardiovascular mortality, with sudden events during treatment posing a critical threat to survival. These risks are particularly pronounced in high-risk populations, such as patients recovering from cardiovascular surgery or those being treated for sepsis. Therefore, the development of effective preventive strategies is essential for improving patient outcomes. This study aimed to develop a machine learning model that uses pretreatment patient characteristics to predict sudden adverse events during HD and within 24 h after treatment in high-risk inpatients at acute care hospitals.

Methods: His retrospective study analyzed data from 739 patients who underwent HD at Hirosaki University Hospital between 2018 and 2021. Sudden events were defined as fatal arrhythmia, refractory intradialytic hypotension, or respiratory arrest. A logistic regression model was constructed using backward stepwise selection from 51 patient characteristics (demographic data, clinical parameters, laboratory data, and HD-related information).

Results: Among the 739 patients, 17 (2.3%) experienced sudden events. The model identified 23 pre-HD covariates and achieved an area under the receiver operating characteristic curve (AUC) of 0.889. Key covariates included emergency hospitalization (present in 71% of patients with sudden events), recent surgery (76%), shorter HD history, elevated pre-HD heart rate, lower serum albumin levels, and higher C-reactive protein concentrations.

Conclusions: Our model enables the early identification of high-risk inpatients receiving hemodialysis using pre-dialysis data, thereby supporting timely clinical interventions, optimized resource allocation, and improved patient safety.

Background: Heart transplantation is curative for advanced heart failure; however, the limited availability of suitable donor organs makes mechanical circulatory support devices a crucial alternative. BiVACOR's total artificial heart (TAH) is a new device that provides full replacement of the organic failing heart to support systemic and pulmonary circulation using a single, magnetically levitated centrifugal rotor. The aim of this study was to assess the in vitro hemocompatibility of the TAH operating in either continuous flow (CF) or pulsatile flow (PF) mode.

Methods: Cattle blood was circulated in an in vitro blood loop at 5 L/min against 100 mmHg for 6 h using the TAH in CF (n = 6) or PF (n = 6), which were compared with a reference pump (CentriMag; n = 6). Blood analysis included hematology, plasma free-hemoglobin, and von Willebrand factor (vWF) multimers.

Results: The normalized indexes of hemolysis were 0.004 ± 0.003 g/100 L for CF, 0.004 ± 0.003 g/100 L for PF, and 0.003 ± 0.002 g/100 L for reference. Basic hematology and vWF multimers were affected in a linear manner, but did not vary between flow regimes or devices.

Conclusions: BiVACOR's TAH operated in a manner requisite of complete heart support, generated comparable in vitro blood compatibility to the clinically approved reference pump, as evidenced by hematological parameters and vWF analyses. The presence of a large pulse pressure did not impact hemocompatibility, which is a positive sign for future applications.

Background: To assess hemolysis potential, blood pump developers frequently perform in vitro testing in accordance with the ASTM F1841 standard. However, options in test parameters such as blood species, anticoagulant, and blood collection and preparation methods can lead to inconsistent hemolysis results.

Methods: To improve in vitro hemolysis test sensitivity and characterize the impact of species and hematocrit (HCT) on flow-induced hemolysis, a pressure-driven, single-pass micro-nozzle test system with short blood exposure times was developed. To compare different blood species, porcine, bovine, ovine, and human blood pools were adjusted to 35% HCT, and 2.7 mL blood aliquots were pneumatically injected at different flow rates through two converging nozzle tips with diameters of 250 and 410 μm. Plasma-free hemoglobin (pfHb) concentration was measured to assess hemolysis after passing through the nozzle tip model. Additionally, porcine blood was tested at 25%, 35%, and 45% HCT using the 410 μm nozzle.

Results: Using a single blood source, the repeatability for a single nozzle and reproducibility based on five separate nozzles were characterized. Results for the nozzles were consistent, with coefficients of variation of 0.5% for flow rate and less than 16% for pfHb levels. Hemolysis increased markedly with flow rate for all species, with pfHb levels being lowest for ovine and bovine blood and highest for human blood. Additionally, hemolysis increased non-linearly with increasing HCT.

Conclusion: The nozzle tip model can be used to examine other blood factors that impact hemolysis and to support and advance computational fluid dynamics hemolysis simulations.

Background: Current guidelines recommend immediate surgical repair for post-infarct ventricular septal rupture (VSR); however, mortality remains exceedingly high. We sought to report outcomes following delayed surgical management bridged with microaxial support.

Methods: A comprehensive literature search yielded 42 case reports/series comprising 78 patients who were initiated on microaxial support following the diagnosis of post-infarct VSR. Patient-level data were extracted and analyzed according to survival status.

Results: Overall, 78% (54/69) of patients were male, and the median age was 69 [IQR: 60-74] years, with no difference in age between survivors and non-survivors. Those who survived were significantly less likely to have a history of prior cardiac surgery than non-survivors [3% (1/30) vs. 43% (3/7), p = 0.016], and less likely to have undergone percutaneous coronary intervention at the time of presentation [41% (22/54) vs. 69% (11/16), p = 0.049]. There were no significant differences in culprit vessel (p = 0.875), VSR size (p = 1), or VSR location (p = 0.253). Those who survived had a significantly higher median Qp/Qs ratio than non-survivors [3.0 [2.3-3.8] vs. 2.1 [1.9-2.3], p = 0.038]. Patients were successfully bridged to definitive surgical management in 76% (59/78) of cases at a median time of 8 [5-14] days following microaxial support placement. The 30-day/in-hospital mortality rate was 22% (17/78), and the overall mortality rate was 27% (21/78).

Conclusion: Microaxial devices can safely and feasibly provide the necessary support to allow for a successful delayed repair in hemodynamically unstable patients following post-infarct VSR.