Direct Oral Anticoagulants Versus Vitamin K Antagonists for the Treatment of Left Ventricular Thrombi-Insights from a Swiss Multicenter Registry.

Current guidelines recommend vitamin K antagonists (VKAs) for the treatment of a left ventricular thrombus (LVT). However, direct oral anticoagulants (DOACs) show superior safety and efficacy compared with VKAs in most thromboembolic disorders. Nevertheless, DOACs remain poorly investigated for the treatment of LVT. To describe the thrombus resolution rate and clinical efficacy of DOACs versus VKAs in patients with LVT, we analyzed consecutive patients with confirmed LVT from a multicenter echocardiography database. Echocardiograms and clinical end points were evaluated independently. The thrombus resolution rate and clinical outcomes were compared according to the underlying anticoagulation regimen. In total, 101 patients were included (17.8% women, mean age 63.3 ± 13.2 years), 50.5% had recently experienced a myocardial infarction. The mean left ventricular ejection fraction was 36.6 ± 12.2%. DOACs versus VKAs were used in 48 and 53 patients, respectively. The median follow-up was 26.6 (interquartile range 11.8;41.2) months. Among patients receiving VKAs compared with DOACs, the thrombus resolved more rapidly within the first month in those taking VKAs (p = 0.049). No differences were seen between the 2 groups with respect to major bleedings, strokes, and other thromboembolic events. In each group, LVT recurred in 3 of the subjects (a total of 6) after discontinuation of anticoagulation. In conclusion, DOACs appear to be a safe and effective alternative to VKAs for the treatment of LVTs, but the rate of thrombus dissolution within 1 month after initiation of anticoagulation appears to be higher with VKAs. A sufficiently powered randomized trial is required to definitively define the role of DOACs in the treatment of LVT.

Temperature Analyses in Fused Filament Fabrication: From Filament Entering the Hot-End to the Printed Parts.

This article analyzes temperature fields and their variations in fused filament fabrication (FFF) from the filament entering the hot-end to the printed parts, aiming at a deeper understanding of the thermal process of this additive manufacturing technology. A standard E3D print head assembly was mounted on a robot arm for printing. A stable filament feeding region was determined with an upper limit in the volume flow rate at different nozzle temperatures. Within the limit, the steady-state temperature fields inside the hot-end were studied by a computational fluid dynamics model. Simulations indicated that the temperature became less homogeneous at higher flow rates, leading to a lower extrudate temperature at the nozzle outlet. These outlet temperatures were analyzed, validated, and used as input to simulate temperature variations in printed parts with a self-developed open-access numerical model. An interlayer time similarity rule was found in printing single-walled geometries, which specifies temperature similarities at the same interlayer time. The findings provide new insights into FFF processes, pointing out opportunities for improved production efficiency and scalability to large-scale manufacturing.

A study on the efficacy of AFO stiffness prescriptions.

PURPOSE: Ankle foot orthosis (AFO) stiffness is a key characteristic that determines how much support or restraint an AFO can provide. Thus, the goal of the current study is twofold: (1) to quantify AFO prescriptions for a group of patients; (2) to evaluate what impact these AFO have on the push-off phase. METHOD: Six patients were included in the study. Three patients were prescribed an AFO for ankle support and three patients were prescribed an AFO for ankle and knee support. Two types of AFO - a traditional polypropylene AFO (AFOPP) and a novel carbon-selective laser sintered polyamide AFO (AFOPA), were produced for each patient. AFO ankle stiffness was measured in a dedicated test rig. Gait analysis was performed under shod and orthotic conditions. RESULTS: Patient mass normalized AFOPP stiffness for ankle support ranged from 0.042 to 0.069 N·m·deg-1·kg-1, while for ankle and knee support it ranged from 0.081 to 0.127 N·m·deg-1·kg-1. On the group level, the ankle range of motion and mean ankle velocity in the push-off phase significantly decreased in both orthotic conditions, while peak ankle push-off power decreased non-significantly. Accordingly, on the group level, no significant improvements in walking speed were observed. However, after patient differentiation into good and bad responders it was found that in good responders peak ankle push-off power tended to be preserved and walking speed tended to increase. CONCLUSIONS: Quantification of AFO stiffness may help to understand why certain orthotic interventions are successful (unsuccessful) and ultimately lead to better AFO prescriptions. Implications for rehabilitation AFO ankle stiffness is key characteristic that determines how much support or restraint an AFO can provide. In a typical clinical setting, AFO ankle stiffness is not quantified. AFO has to meet individual patient's biomechanical needs. More objective AFO prescription and more controlled AFO production methods are needed to increase AFO success rate.