In vitro hemodynamics of fabric composite membrane for cardiac valve prosthesis replacement.

This study aimed to investigate the hemodynamics of a novel fabric composite that can be used as a substitute for bovine pericardium. The structure is composed of ultrahigh molecular weight polyethylene (UHMWPE) fabric coated with thermoplastic polyurethane (TPU) membranes on both sides. In vitro experiments were carried out on two composite valve samples with different specifications and a bovine pericardial one with the same dimension and structure. Hemodynamic properties including the effective orifice area (EOA) and regurgitant fraction (RF) were obtained and compared through pulsatile-flow testing in a pulse duplicator. Using the particle image velocimetry (PIV) technique, frames of the downstream velocity field in the aortic valve chamber were captured during cardiac cycles. Then, the field of Reynolds shear stress (RSS), viscous shear stress (VSS), and turbulent kinetic energy (TKE) at peak systole were calculated. A fluid-structure interaction (FSI) model has also been used to verify the pulsatile-flow testing. Compared with the bovine pericardial valve, composite valves have nosuperiority regarding EOA and RF due to their slightly higher rigidity. However, shear stresses of composite valves were lower than those of the bovine pericardial valve indicating more stable blood flows, which means that composite leaflets have the potential to reduce the risks of thrombosis and hemolysis induced by the mechanical contact between the blood flow and leaflets of valve prostheses.

Mechanical behaviors of high-strength fabric composite membrane designed for cardiac valve prosthesis replacement.

Bovine pericardium has been commonly used as leaflets in cardiac valve prosthesis replacement for decades because of its good short-term hemocompatibility and hemodynamic performance. However, fatigue, abrasion, permanent deformation, calcification, and many other failure modes have been reported as well. The degradation of the performance will have a serious impact on the function of valve prostheses, posing a risk to the patient's health. This study aimed to introduce a flexible fabric composite with better mechanical performance such that it can be employed as a substitute material for bioprosthetic valve leaflets. This composite has a multilayered thin film structure made of ultrahigh molecular weight polyethylene (UHMWPE) fabric and thermoplastic polyurethane (TPU) membranes. The mechanical properties of three specifications with different design parameters were tested. The tensile strength, shear behavior, tear resistance, and bending stiffness of the composites were characterized and compared to those of bovine pericardium. A constitutive model was also established to describe the composites' mechanical behaviors and predict their strength. According to the results of the tests, the composite could maintain a flexible bending stiffness with high in-plane tensile strength and tear strength. Therefore, bioprosthetic valve made of this substitute material can withstand harsher loads in the blood flow environment than those made of bovine pericardium. Moreover, all these test results and constitutive models can be used in future research to evaluate hemodynamic performance and clinical applications of fabric composite valve prostheses.

Association between SLICC/ACR damage index and outcomes for lupus patients after cardiac valve surgery.

Systemic lupus erythematosus (SLE) is associated with multi-organ damage including cardiac valve, which may need valvular operation. However, methods for outcome prediction and prosthetic valve selection are unclear in SLE patients undergoing cardiac valve surgery. Twenty-five SLE patients receiving valvular operation in a single institute between 2002 and 2020 were enrolled. Systemic Lupus International Collaborative Clinics/American College of Rheumatology Damage Index (SLICC/ACR damage index, SDI) was applied to evaluate the damage severity. Clinical outcomes were compared between patients with different SDI. The hospital survival rate was 88%, and long-term survival rate was 59.5% and 40.2% at 5 and 10 years. The median SDI was 4 (interquartile range 3-6) in our study, patients were then grouped into higher SDI (defined as SDI ≥ 5, n = 11) and lower SDI group (defined as SDI < 5, n = 14). The in-hospital survival rate (72.2% vs 100%, P = 0.074) and 5-year survival rate (18.2% vs 92.9%, P < 0.001) were lower in higher SDI group, compared to lower SDI group. SDI score was associated with long-term outcome for SLE patients receiving cardiac valve surgery. SDI ≥ 5 was associated with very poor long-term outcomes. This finding implicates that xenograft might be a reasonable choice for SLE patients with SDI ≥ 5.

[Knowledge about warfarin treatment in patients with atrial fibrillation or mechanical prosthetic valves]. / Conocimientos acerca del tratamiento con warfarina en pacientes con fibrilación auricular o portadores de válvulas protésicas mecánicas.

Objective: To determine the degree of knowledge about warfarin treatment in patients with atrial fibrillation or with mechanical prosthetic valves. Materials and methods: Descriptive, observational, cross-sectional study. The OAK test was applied to all adult patients with a diagnosis of atrial fibrillation or with mechanical prosthetic valves treated with warfarin, who attended the hematology consultation from May 17 to November 10, 2022, at the "Instituto Nacional Cardiovascular Carlos Alberto Peschiera Carrillo". Results: A total of 150 patients participated, 64% were male, with a mean age of 60.3 ± 15 years, 45.3% with a diagnosis of atrial fibrillation and 54.7% with mechanical prosthetic valves. The mean OAK test score was 44.4% (8.4/19), only 6% (n=9) achieved a satisfactory score ≥75.0%, the percentage of correct answers according to dimensions was: 68 % in forms of use, 39.3% in interactions and complications and 41.1% in INR control. A 40.7% did not understand the meaning of the term INR and 81.3% did not know their optimal values. Conclusions: The patient's degree of knowledge about warfarin treatment was inadequate; both in its use, interactions and complications. Considering that it is a difficult drug to use, due to its narrow therapeutic window and its multiple interactions, inadequate knowledge of its use may contribute to inappropriate anticoagulation.

Complications of TAVR From an Anesthesia Perspective.

Description Transcatheter aortic valve replacement (TAVR) has become the predominant technique for aortic valve replacement in the United States. Initially approved for high surgical risk patients, TAVR is now approved for most patients requiring valve therapy, including younger, lower-risk patients. The procedure is ideally performed in a hybrid operating room equipped with fluoroscopic equipment and transesophageal echocardiogram (TEE) imaging that can be viewed simultaneously by the operating team. The operating room should also be equipped to allow initiation of cardiopulmonary bypass, if necessary. Cardiac anesthesia teams are often involved with the management of these patients. This mini-review is designed to summarize potential complications that anesthesiologists may contend with during TAVR.

[Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves]. / Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas / Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value (SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.