Prevalence of donor-transmitted atherosclerosis—Clinical utility of intracoronary ultrasound early after heart transplantation. A single-center study

AbstractIntroductionCoronary allograft vasculopathy (CAV) is one of the main factors limiting long-term survival following orthotopic heart transplantation (HTx). Whether or not and, if so, how donor-transmitted atherosclerosis (DCA) affects the post-transplant course of the allograft recipient is still unclear. Conventional coronary angiography is a moderately accurate technique for DCA detection as it will reveal only the more gross morphological lesions. By contrast, intravascular ultrasound (IVUS) has been shown to be a much more sensitive technique for CAV and DCA detection. In our study we sought to determine the prevalence of DCA in our HTx patient population and identify main risk factors of DCA based on donor characteristics.Patients and methodsWe performed a retrospective analysis of data of 119 patients (92 men, 27 women) undergoing transplantation in our center from August 2006 through September 2012, who had survived their first post-transplant month and had coronary angiography and IVUS.ResultsDCA was present in 39 patients, and not documented in 80 patients. The main risk factors for DCA included donor age, cigarette smoking, and hypertension; the other parameters were not shown to be statistically significant. In-hospital mortality was low in both groups (DCA positive and DCA negative), with one patient dying in either group. One-year mortality rates post-HTx were likewise almost identical in both groups (15.4% and 15% in DCA positive and negative, respectively).ConclusionThe prevalence of DCA in our patients was 32.8%, with major risk factors for DCA including donor age, cigarette smoking, and hypertension. As age seems to be the strongest predictor, coronary angiography should be a routine examination in individuals aged over 40 years; the examination should be considered in younger individuals with a cluster of several of risk factors. The 1-year survival in this selected patient population was identical in both groups, the implication being that the diagnosis of DCA had no effect on 1-year survival post-HTx

Minimally invasive implantation of left ventricular assist device HeartWare HVAD

AbstractIntroductionLong-term left ventricular assist devices are nowadays part of standard therapy for patients in terminal phase of heart failure. Lower invasiveness of implantation might have the potential to enhance results of these high risk patients. The aim of this study is to introduce our minimally invasive approach to the implantation of left ventricular assist device of the latest generation HeartWare ventricle assist device (HVAD) and our initial experience with this method.MethodsIn our department we implanted HVAD between November 2013 and November 2014 in 8 patients as a bridge to heart transplantation. All patients were male with average age 59.5±6.4 years. Basic diseases were dilated cardiomyopathy in 6 patients (75%), ischemic cardiomyopathy in 2 patients (25%). The mean value of left ventricular ejection fraction was 10±3.6%, right ventricular ejection fraction was 35±5.6%. Access to the left ventricular apex was reached by left-sided thoracotomy of approximately 8cm. To access the ascending aorta we used upper J ministernotomy.ResultsMinimally invasive implantation was successfully done in all patients. In one patient closure of foramen ovale was simultaneously performed. Most patients (75%) were extubated on the first postoperative day. In one case, a failure of the right ventricle occurred with the need for temporary right-sided circulatory support device Centrimag. No patient died, four patients have successfully undergone heart transplantation, other are followed on an outpatient basis.ConclusionMinimally invasive implantation of left ventricular assist device HeartWare HVAD is safely feasible. After a very good initial experience with this technique it has become the method of choice in our department

In-situ X-ray Differential Micro-tomography for Investigation of Water-weakening in Quasi-brittle Materials Subjected to Four-point Bending

Several methods, including X-ray radiography, have been developed for the investigation of the characteristics of water-saturated quasi-brittle materials. Here, the water content is one of the most important factors influencing their strength and fracture properties, in particular, as regards to porous building materials. However, the research concentrated on the three-dimensional fracture propagation characteristics is still significantly limited due to the problems encountered with the instrumentation requirements and the size effect. In this paper, we study the influence of the water content in a natural quasi-brittle material on its mechanical characteristics and fracture development during in-situ four-point bending by employing high-resolution X-ray differential micro-tomography. The cylindrical samples with a chevron notch were loaded using an in-house designed four-point bending loading device with the vertical orientation of the sample. The in-house designed modular micro-CT scanner was used for the visualisation of the specimen’s behaviour during the loading experiments. Several tomographic scans were performed throughout the force-displacement diagrams of the samples. The reconstructed 3D images were processed using an in-house developed differential tomography and digital volume correlation algorithms. The apparent reduction in the ultimate strength was observed due to the moisture content. The crack growth process in the water-saturated specimens was identified to be different in comparison with the dry specimens

FeOx/Al2O3 katalyzátory pro vysokoteplotní rozklad N2O za podmínek oxidace NH3 ve výrobnách kyseliny dusičné

The catalytic activity of a series of FeOx/Al2O3 prepared under various conditions was evaluated for high temperature decomposition of N2O (HT-deN(2)O) in a complex gas mixture produced by oxidation of ammonia. Thus the relevant step in the industrial nitric acid production process was simulated. The catalyst stability during long-term exposure (12 days) to reaction conditions relevant to HT-deN(2)O was studied. Both fresh and aged FeOx/Al2O3 exhibited more than 90% conversion of N2O in the 750-900 degrees C temperature range. Structural analysis showed that the prepared FeOx/Al2O3 catalysts contained various proportions of , and alumina phases and up to four individual iron species. In the and Al2O3 phases, well stabilized Fe(iii) in T-d or O-h coordination was identified as the active species in HT-deN(2)O.Katalytická aktivita série katalyzátorů FeOx/Al2O3 připravených za různých podmínek byla testována pro vysokoteplotní rozklad N2O (HT-deN2O) v komplexní směsi vznijkající při spalování amoniaku, čímž byly simulovány podmínky z výroben kyseliny dusičné. Byla studována stabilita katalyzátorů během dlouhodobé (12 dní) zátěže. Jak čerstvě připravené, tak i zestárlé katalyzátory vykazovaly více než 90% konverzi N2O v teplotním rozsahu 750-900 °C. Strukturní analýza ukázala, že FeOx/Al2O3 katalyzátory obsahovaly různá množství δ, θ a α aluminy a až 4 druhy iontu železa. Ve formách δ a θ Al2O3 je dobře stabilůizováno Fe(III) v Td nebo Oh koordinaci, které bylo identifikováno jako aktivní centrum v HT-deN2O

Comparison of bicuspidization and Ross procedure in the treatment of unicuspid aortic valve disease in adults - Insight from the AVIATOR registry.

BACKGROUND: Unicuspid aortic valve (UAV) is the second most common underlying cause of aortic valve dysfunction in young adults after the bicuspid valve. The valve may be replaced (for example by pulmonary autograft) or repaired using the bicuspidization technique. The aim of our study was to compare short- and mid-term outcomes of Ross procedure with bicuspidization in patients with severe UAV dysfunction. METHODS: This was a multi-center retrospective observational cohort study comparing data from two dedicated Ross centers in the Czech Republic with bicuspidization outcomes provided by AVIATOR registry. As for the Ross group, only the patients with UAV were included. Primary endpoint was mid-term freedom from reintervention. Secondary endpoints were mid-term freedom from major adverse events, endocarditis and pacemaker implantation. RESULTS: Throughout the study period, 114 patients underwent the Ross procedure (years 2009-2020) and 126 patients underwent bicuspidization (years 2006-2019). The bicuspidization group was significantly younger and presented with a higher degree of dyspnea, a lower degree of aortic valve stenosis and more often with pure regurgitation. The primary endpoint occurred more frequently in the bicuspidization group than in the Ross group - 77.9 vs. 97.9 % at 5 years and 68.4 vs. 75.2 % at 10 years (p < 0.001). There was no difference in secondary endpoints. CONCLUSION: Ross procedure might offer a significantly lower mid-term risk of reintervention than bicuspidization in patients with UAV. Both procedures have comparable survival and risk of other short- and mid-term complications postoperatively

Serum transferrin as a biomarker of hepatocyte nuclear factor 4 alpha activity and hepatocyte function in liver diseases

International audienceBackground: Serum transferrin levels represent an independent predictor of mortality in patients with liver failure. Hepatocyte nuclear factor 4 alpha (HNF4α) is a master regulator of hepatocyte functions. The aim of this study was to explore whether serum transferrin reflects HNF4α activity. Methods: Factors regulating transferrin expression in alcoholic hepatitis (AH) were assessed via transcriptomic/ methylomic analysis as well as chromatin immunoprecipitation coupled to DNA sequencing. The findings were corroborated in primary hepatocytes. Serum and liver samples from 40 patients with advanced liver disease of multiple etiologies were also studied. Results: In patients with advanced liver disease, serum transferrin levels correlated with hepatic transferrin expression (r = 0.51, p = 0.01). Immunohistochemical and biochemical tests confirmed reduced HNF4α and transferrin protein levels in individuals with cirrhosis. In AH, hepatic gene-gene correlation analysis in liver transcriptome revealed an enrichment of HNF4α signature in transferrin-correlated transcriptome while transforming growth factor beta 1 (TGFβ1), tumor necrosis factor α (TNFα), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) negatively associated with transferrin signature. A key regulatory region in transferrin promoter was hypermethylated in patients with AH. In primary hepatocytes, treatment with TGFβ1 or the HNF4α inhibitor BI6015 suppressed transferrin production, while exposure to TNFα, IL-1β, and IL-6 had no effect. The correlation between hepatic HNF4A and transferrin mRNA levels was also seen in advanced liver disease. Conclusions: Serum transferrin levels constitute a prognostic and mechanistic biomarker. Consequently, they may serve as a surrogate of impaired hepatic HNF4α signaling and liver failure

Left atrial appendage occlusion during cardiac surgery to prevent stroke

BACKGROUND Surgical occlusion of the left atrial appendage has been hypothesized to prevent ischemic stroke in patients with atrial fibrillation, but this has not been proved. The procedure can be performed during cardiac surgery undertaken for other reasons. METHODS We conducted a multicenter, randomized trial involving participants with atrial fibrillation and a CHA2DS2-VASc score of at least 2 (on a scale from 0 to 9, with higher scores indicating greater risk of stroke) who were scheduled to undergo cardiac surgery for another indication. The participants were randomly assigned to undergo or not undergo occlusion of the left atrial appendage during surgery; all the participants were expected to receive usual care, including oral anticoagulation, during follow-up. The primary outcome was the occurrence of ischemic stroke (including transient ischemic attack with positive neuroimaging) or systemic embolism. The participants, research personnel, and primary care physicians (other than the surgeons) were unaware of the trial-group assignments. RESULTS The primary analysis population included 2379 participants in the occlusion group and 2391 in the no-occlusion group, with a mean age of 71 years and a mean CHA2DS2-VASc score of 4.2. The participants were followed for a mean of 3.8 years. A total of 92.1% of the participants received the assigned procedure, and at 3 years, 76.8% of the participants continued to receive oral anticoagulation. Stroke or systemic embolism occurred in 114 participants (4.8%) in the occlusion group and in 168 (7.0%) in the no-occlusion group (hazard ratio, 0.67; 95% confidence interval, 0.53 to 0.85; P=0.001). The incidence of perioperative bleeding, heart failure, or death did not differ significantly between the trial groups. CONCLUSIONS Among participants with atrial fibrillation who had undergone cardiac surgery, most of whom continued to receive ongoing antithrombotic therapy, the risk of ischemic stroke or systemic embolism was lower with concomitant left atrial appendage occlusion performed during the surgery than without it