International Journal of Artificial Organs最新文献

Globally, heart disease (HD) persists as a major contributor to mortality rates, requiring accurate and efficient diagnostic models. While machine learning has shown promise in early detection, challenges such as missing data, class imbalance, suboptimal feature selection, and inefficient hyperparameter tuning hinder predictive accuracy and reliability. Many existing models fail to effectively preprocess medical datasets, leading to biased and computationally expensive predictions. To address these issues, this study proposes a strong hybrid framework for HD prediction. The Balanced Imputation-Normalization Framework incorporates K-Nearest Neighbors (KNN) imputation, StandardScaler normalization, and the Synthetic Minority Oversampling Technique (SMOTE). KNN imputation effectively handles missing data, ensuring reliable representation, while StandardScaler normalization standardizes feature values to enhance model stability. SMOTE is applied to address class imbalance, synthetic samples are generated to augment the minority class. Feature selection is optimized using the Hungarian algorithm, which systematically selects the most relevant attributes while reducing redundancy. Additionally, Bayesian optimization fine-tunes hyperparameters to improve classification performance. For prediction, an ensemble learning approach combines Random Forest (RF), Decision Tree (DT), K-Nearest Neighbors (KNN), Naïve Bayes (NB), and Extreme Gradient Boosting (XGBoost). The Voting Ensemble aggregates predictions using hard and soft voting mechanisms, improving robustness and generalization. Experimental results on benchmark heart disease datasets demonstrate that XGBoost attained a peak accuracy of 96.43%, with subsequent results from the Voting Ensemble at 95.66%, significantly outperforming traditional models and demonstrating that ensemble learning effectively improves accuracy and reduces computational complexity.

Introduction: Renal replacement therapy efficiently eliminates cefepime. A published in vitro study concluded to minimal adsorption of cefepime in a polysulfone derived filter. We aimed at assessing cefepime adsorption in filters used in critically ill patients.

Methods: Two filters were used, ST™150 and AV™1000. Adsorption was assessed in two modes, including diafiltration and filtration set to flow rates of from 2.5 to 1 L/h, respectively. Routes of elimination were assessed using NeckEpur^® method for 6-h session duration.

Results: The mean initial concentration in the 5-L central compartment (CC) in the 10 sessions was 47.7 ± 2.9 mg/L. Using the diafiltration mode, the mean adsorption rates in the ST™150 and AV™1000 were 1.3 ± 2.3% and 19.7 ± 1.2% (n = 3), respectively. Using the filtration mode at 1 L/h, the mean adsorption rates in the ST™150 and AV™1000 were 1.7% (n = 2) and 18.5% (n = 2), respectively.

Conclusion: ST™150 filter sequestrated very limited quantities of cefepime. In the diafiltration and filtration modes, AV™1000 sequestered cefepime at about 19%. The adsorption rate seems independent of the flow rate. Further studies would be needed to assess, in particular, the clinical relevance of these results in adults as well as drug adsorption in the pediatric population.

Achieving optimal unloading in patients with left ventricular assist devices (LVADs) is associated with improved outcomes but remains unattainable in some cases. We retrospectively reviewed 33 patients with a HeartMate 3 LVAD who underwent speed optimization with concomitant echocardiography and right heart catheterization for inadequate left ventricular (LV) unloading between January 2016 and December 2023. Patients were stratified based on left ventricular transmural pressure (LVTMP) into two groups: LVTMP ⩽7 mmHg and LVTMP >7 mmHg using a median split approach. Pulmonary capillary wedge pressure (PCWP) decreased in both groups with increased LVAD speed; however, the mean PCWP change per 100 rpm was significantly smaller in patients with LVTMP ⩽7 mmHg (-0.50 vs -0.99 mmHg per 100 rpm, p = 0.003). Comparative analysis demonstrated LVTMP's superiority over established RV markers, with the strongest interaction effect for predicting speed optimization response. Changes in cardiac output were similar between the two groups. In univariate analysis, multiple hemodynamic parameters were significantly associated with reduced LVTMP, including right atrial pressure (OR = 1.27, p = 0.036), TPG (OR = 1.25, p = 0.037), DPG (OR = 1.69, p = 0.012), and PAPi (OR = 0.35, p = 0.019).LVTMP, as a surrogate for true LV preload, particularly in the context of RV failure, may offer predictive value for the success or failure of LV unloading with LVAD speed optimization.

Background: Mitral transcatheter edge-to-edge repair (M-TEER) has improved outcomes in selected patients with secondary mitral regurgitation (MR). However, patients can experience progressive heart failure (HF), subsequently requiring durable mechanical support with left ventricular assist devices (LVAD). Optimal management strategies for M-TEER devices during LVAD implantation remain unclear.

Methods: This retrospective multicenter study included consecutive patients who underwent LVAD implantation following prior M-TEER for secondary MR at three tertiary Italian centers (2012-2022). Patients were categorized based on clip management during LVAD surgery: surgical removal, retention with elevated residual mitral gradient (⩾5 mmHg), or retention with normal gradient (<5 mmHg). The primary endpoint was a composite of all-cause mortality or HF hospitalization.

Results: A total of 28 patients were included, with a median age of 64 years; 86% were male. Median interval from M-TEER to LVAD implantation was 378 days. Clip removal was performed in 5 patients (18%), while 23 (82%) retained the clip (3 with elevated and 20 with normal gradients). MR improved significantly post-LVAD implantation in all groups. In-hospital mortality was 11%, higher (40%) in patients undergoing clip removal. At a median follow-up of 35 months, the composite endpoint occurred in 63% of patients without significant differences between groups (p = 0.60).

Conclusions: LVAD implantation following M-TEER therapy is feasible, with acceptable perioperative and mid-term outcomes. Retaining the clip is safe, particularly if residual MV gradients are low.

Background: The ideal dialysate potassium concentration for patients with hyperkalemia undergoing maintenance hemodialysis is debated. While low-potassium dialysate enhances potassium removal, a steep serum-todialysate potassium gradient may provoke arrhythmias. This study aimed to assess the efficacy of a two-phase dialysate potassium profiling strategy.

Materials and methods: Patients aged 18-60 years with end-stage renal disease and predialysis hyperkalemia were randomized into two groups for twice-weekly hemodialysis. Group A received 2 mEq/L potassium dialysate for the first hour, followed by 0 mEq/L for the next 3 h. Group B received a constant 2 mEq/L potassium dialysate throughout the 4-h session. Serum potassium was measured pre-dialysis and hourly during the session. Patients were monitored for cardiac arrhythmias.

Results: Of 145 patients screened, 60 were enrolled (30 per group). The majority were male (66.7% in Group A and 56.7% in Group B), with over 50% having diabetes and 85% hypertension, indicating high cardiovascular risk. Predialysis potassium levels were similar (6.00 ± 0.3 mEq/L in Group A vs 5.98 ± 0.34 mEq/L in Group B). Group A achieved significantly lower post-dialysis potassium levels (3.48 ± 0.22 mEq/L) than Group B (3.72 ± 0.42 mEq/L; p = 0.008). One case of ventricular ectopy was observed in each group, both managed conservatively.

Conclusion: Two-phase dialysate potassium profiling effectively lowers serum potassium more than a fixed approach, without a significant increase in arrhythmic events, supporting its use in managing hyperkalemia in hemodialysis patients.

Forty five years morbidly obese male with prosthetic mitral and aortic valve referred to our hospital with dengue shock syndrome. He had recurrent ventricular arrhythmias required multiple shock and short cycle of cardiopulmonary resuscitation (CPR). He was supported with high dose vasopressors and mechanical ventilation. Two-dimensional Echocardiography showed severe left ventricular (LV) dysfunction with left ventricular ejection fraction (LVEF) 8%-10% and mild increase in the gradient across aortic and mitral valve however there was no para-valvular leak or vegetations. Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) was initiated along with continuous renal replacement therapy (CRRT) using Oxiris^® filter in view of persistent ventricular arrhythmia, acute kidney injury (AKI) Grade 3 and severe acute hepatic dysfunction. The major concerns were severe myocardial dysfunction and malignant arrhythmias with impending cardiac arrest warranting the need for VA ECMO support while prosthetic valves especially aortic, uncertainty regarding myocardial dysfunction whether pre-existing or dengue induced and severe dysfunction of other organs were challenges for decision to initiate ECMO. This case describes successful ECMO management and challenges due to prosthetic valve as well as pre-existing severe myocardial dysfunction and concurrent other organ dysfunction.

Objective: This study aims to evaluate the clinical and demographic factors influencing the restoration of sinus rhythm and postoperative outcomes in patients undergoing bipolar radiofrequency ablation (RFA) concomitant with mitral valve surgery. By analyzing the associations between rhythm outcomes, mortality, and patient characteristics, this study seeks to identify predictors of ablation success and provide valuable insights into optimizing treatment strategies for atrial fibrillation in this high-risk patient population.

Methods: Demographic and clinical characteristics of the patients were analyzed. Postoperative electrocardiography (ECG) findings during the first year after surgery were used to classify patients into two groups: those who achieved sinus rhythm (SR) and those who remained in atrial fibrillation (AF). Additionally, patients were categorized into survivors and non-survivors within the first postoperative year for statistical comparisons.

Results: The overall rate of sinus rhythm (SR) restoration within the first year after radiofrequency (RF) ablation was 70.2% (n = 85). When comparing patients who achieved SR with those who remained in atrial fibrillation (AF) postoperatively, the AF group exhibited significantly larger preoperative ascending aortic diameters, left atrial diameters, and interventricular septal thicknesses, along with lower ejection fractions on transthoracic echocardiography (TTE) (p = <0.001, 0.015, 0.012, and 0.024, respectively).

Conclusions: Radiofrequency ablation is a safe and effective method for maintaining long-term sinus rhythm, with no additional complications. It is associated with a low risk of morbidity and thromboembolic complications.

Purpose: To date, there are no effective therapeutic strategies for hepatocellular carcinoma (HCC). Traditionally, researches on HCC were carried out using hepatocellular carcinoma cells, organoids, and animal models. However, these models cannot accurately replicate the pathophysiological conditions underlying the onset and progression of human HCC. Therefore, more effective disease models are needed to study HCC.

Methods: Ten disease livers from HCC patients who underwent transplantation were subjected to normothermic machine perfusion (NMP) via the hepatic artery and portal vein in vitro. Perfusion parameters, blood gas levels, and contrast-enhanced ultrasound (CEUS) were continuously monitored to assess alterations in tumor activity. RNA sequencing (RNA-seq) and next-generation sequencing (NGS) of circulating tumor DNA (ctDNA) were employed to assess the preservation of hepatic tissue integrity and tumor mutational profiles during in vitro perfusion. Oxaliplatin +5-FU was used to conduct the liver cancer treatment research.

Results: Normothermic machine perfusion successfully maintained liver survival for 92 h in vitro. Contrast-enhanced ultrasound can be used to assess alterations in tumor and liver activity during normothermic machine perfusion. The sequencing analysis revealed that normothermic machine perfusion (NMP) effectively preserved hepatic tissue integrity while retaining tumor genomic stability. The normothermic machine perfusion model of HCC can be used for the study of anti-cancer therapy.

Conclusions: Contrast-enhanced ultrasound can monitor alterations in tumor and liver activity, while normothermic machine perfusion can sustain the long-term survival of the liver in vitro, thus maintaining normal tumor characteristics. Therefore, this model provides a novel approach for studying tumor therapy.

Background: High shear rate and non-physiological turbulent flow caused by bileaflet mechanical heart valves (BMHVs) lead to platelet activation and adhesion, which can cause rapid thrombus growth and severe consequences.

Methods: This study employed computational modeling to analyze the effect of surface texture on flow field around the BMHVs. The textures' positional, geometric, and dimensional parameters were optimized based on flow field analysis. The textured BMHVs were then implanted in sheep for 6 months, with pyrolytic carbon BMHVs serving as the control group.

Results: The textured BMHVs significantly reduced high-velocity, low-velocity, high turbulent shear stress, and high shear rate regions in the flow field. Post-implantation, the experimental groups with textured BMHVs exhibited lower levels of platelet activation and neither the intrinsic nor extrinsic coagulation cascade reactions were activated in the sheep. Detailed observations revealed an absence of erythrocyte or platelet adhesion within the grooved texture regions, with minimal adhesion at the peripheral edges of the textured areas.

Conclusion: The optimized surface textures on BMHVs effectively reduce adverse flow conditions and platelet activation, potentially decreasing the need for anticoagulant therapy and minimizing the associated bleeding risks. These findings are crucial for enhancing the long-term safety and efficacy of BMHV implantation.