AN OUTBREAK OF EXTENSIVELY DRUG-RESISTANT ACINETOBACTER BAUMANNII IN A BELGIAN TERTIARY BURN WOUND CENTER.

The burn intensive care unit (ICU) of the Queen Astrid Military Hospital experienced an outbreak with an extensively drug-resistant Acinetobacter baumannii (XDR-Ab) strain, which began when all burn wound patients from all over Belgium were sent there as part of the national COVID-19 action plan. The purpose of this study is to report on the investigation and strategies that were implemented to contain the outbreak. Between October 2020 and May 2021, five of the 72 patients admitted to the ICU met the acute outbreak case definition (attack rate 7%). Their median age was 46 years and their median total body surface area burned was 39%. All patients developed at least one XDR-Ab infection, with in total three pulmonary, three bloodstream and five burn wound infections. One patient died. All XDR-Ab isolates were only susceptible to colistin. Whole genome sequencing of the isolates from the first two patients revealed an identical A. baumannii ST2 genotype, suggesting an outbreak. XDR-Ab-positive patients were cohorted with dedicated staff. The infection control team intensified its training on hand hygiene, excreta management and bio-cleaning procedures. Concurrently, 30 environmental samples were collected, which proved negative for XDR-Ab. Spatio-temporal associations were found for all XDR-Ab-positive patients, suggesting cross-transmission via staff's hands. We describe an XDR-Ab outbreak in a burn ICU over a seven-month period, in a context of increased workload. This series underlines the importance of a correct staff-to-patient ratio, especially in outbreak situations.

L'unité de soins intensifs (USI) pour brûlés de l'Hôpital Militaire Reine Astrid a connu une épidémie avec une souche d'Acinetobacter baumannii extrêmement résistante aux antibiotiques (XDR-Ab), qui a commencé pendant la période où tous les patients brûlés de Belgique y étaient référés à la suite du plan national COVID-19. Le but de cette étude est de décrire l'enquête épidémiologique et les stratégies utilisées pour contenir l'épidémie. Entre octobre 2020 et mai 2021, cinq des 72 patients admis à l'USI ont répondu à la définition de cas (taux d'attaque 7%). L'âge médian était de 46 ans, la surface corporelle brûlée médiane de 39%. Tous les patients ont développé au moins une infection par XDR-Ab : trois pneumonies, trois bactériémies et cinq infections de brûlures. Un patient est décédé. Tous les isolats XDR-Ab n'étaient sensibles qu'à la colistine. Le séquençage du génome entier des isolats des deux premiers patients a révélé un génotype identique d'A. baumannii ST2, suggérant une épidémie. Les patients XDR-Ab positifs ont été cohortés avec du personnel dédié. L'équipe d'hygiène hospitalière a intensifié sa formation sur l'hygiène des mains, la gestion des excréta et les procédures de bio-nettoyage. Simultanément, 30 échantillons environnementaux ont été collectés, qui étaient négatifs pour XDR-Ab. Des liens spatio-temporels ont été trouvés pour tous les patients XDR-Ab positifs, suggérant une transmission croisée manuportée. Nous décrivons une épidémie de XDR-Ab dans une USI pour brûlés sur une période de sept mois, dans un contexte de charge de travail accrue. Cette série souligne l'importance d'un ratio personnel-patients approprié, en particulier dans les situations d'épidémie.

Prognostic value of temporal patterns of left atrial reservoir strain in patients with heart failure with reduced ejection fraction.

BACKGROUND: We investigated whether repeatedly measured left atrial reservoir strain (LASr) in heart failure with reduced ejection fraction (HFrEF) patients provides incremental prognostic value over a single baseline LASr value, and whether temporal patterns of LASr provide incremental prognostic value over temporal patterns of other echocardiographic markers and NT-proBNP. METHODS: In this prospective observational study, 153 patients underwent 6-monthly echocardiography, during a median follow-up of 2.5 years. Speckle tracking echocardiography was used to measure LASr. Hazard ratios (HRs) were calculated for LASr from Cox models (baseline) and joint models (repeated measurements). The primary endpoint (PEP) comprised HF hospitalization, left ventricular assist device, heart transplantation, and cardiovascular death. RESULTS: Mean age was 58 ± 11 years, 76% were men, 82% were in NYHA class I/II, mean LASr was 20.9% ± 11.3%, and mean LVEF was 29% ± 10%. PEP was reached by 50 patients. Baseline and repeated measurements of LASr (HR per SD change (95% CI) 0.20 (0.10-0.41) and (0.13 (0.10-0.29), respectively) were both significantly associated with the PEP, independent of both baseline and repeated measurements of other echo-parameters and NT-proBNP. Although LASr was persistently lower over time in patients with PEP, temporal trajectories did not diverge in patients with versus without the PEP as the PEP approached. CONCLUSION: LASr was associated with adverse events in HFrEF patients, independent of baseline and repeated other echo-parameters and NT-proBNP. Temporal trajectories of LASr showed decreased but stable values in patients with the PEP, and do not provide incremental prognostic value for clinical practice compared to single measurements of LASr.

Five-year prognostic significance of global longitudinal strain in individuals with a hypertrophic cardiomyopathy gene mutation without hypertrophic changes.

BACKGROUND: Previous studies have reported that global longitudinal strain (GLS) is reduced in patients with hypertrophic cardiomyopathy (HCM) while left ventricular ejection fraction (LVEF) is normal. Our aim was to assess GLS in individuals with HCM mutations without hypertrophic changes and to determine its prognostic value for the development of HCM. METHODS AND RESULTS: This retrospective case-control and cohort study included 120 HCM mutation carriers and 110 controls. GLS and LVEF were assessed with Tomtec Imaging software. Age, gender, and body surface area were similar in mutation carriers and controls. Compared to controls, mutation carriers had a higher maximal wall thickness (9 ± 2 vs 8 ± 2 mm, p < 0.001), higher LVEF (60 ± 5 vs 58 ± 4%, p < 0.001) and higher GLS (-21.4 ± 2.3% vs -20.3 ± 2.2%, p < 0.001). The GLS difference was observed in the mid-left ventricle (-21.5 ± 2.5% vs -19.9 ± 2.5%, p < 0.001) and the apex (-24.1 ± 3.5% vs -22.1 ± 3.4%, p < 0.001), but not in the base of the left ventricle (-20.0 ± 3.3% vs -20.0 ± 2.6%, p = 0.9). Echocardiographic follow-up was performed in 80 mutation carriers. During 5.6 ± 2.9 years' follow-up, 13 (16%) mutation carriers developed HCM. Cox regression analysis showed age (hazard ratio (HR) 1.08, p = 0.01), pathological Q wave (HR 8.56; p = 0.01), and maximal wall thickness (HR 1.94; p = 0.01) to be independent predictors of the development of HCM. GLS was not predictive of the development of HCM (HR 0.78, p = 0.07). CONCLUSION: GLS is increased in HCM mutation carriers without hypertrophic changes. GLS was of no clear prognostic value for the development of HCM during follow-up, in contrast to age, pathological Q waves and maximal wall thickness.

Hemophagocytic lymphohistiocytosis associated to Haemophilus parainfluenzae endocarditis- a case report.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe and potentially fatal syndrome that is characterized by increased proliferation and activation of benign macrophages with hemophagocytosis throughout the reticuloendothelial system. This syndrome is classified as primary (genetic) or secondary when acquired in the context of infections (usually viral), malignancies, rheumatologic and metabolic diseases. CASE SUMMARY: We report a case of HLH complicating a Haemophilus parainfluenzae mitral valve endocarditis and resolving under antibiotic and surgical treatment alone. We also review other case reports of infective endocarditis associated with HLH. CONCLUSION: The syndrome is probably underdiagnosed. To our knowledge, this is the first report of a HLH syndrome associated with H. parainfluenzae endocarditis.

Acute coronary syndrome and platypnoea-orthodeoxia with thoracic and interauricular septal aneurysms.

OBJECTIVE: Platypnea-orthodeoxia is a rare syndrome characterized by dyspnea induced by the upright position and relieved by supine position and an arterial deoxygenation increased by the upright position which improves during recumbency. Several anatomical factors that can alter the atrial anatomy and facilitate shunting through an interatrial defect have been related to this syndrome. In many cases, this syndrome has been associated with patent foramen ovale (PFO) and right-to-left shunt. Rarely platypnea-orthodeoxia syndrome has been described associated with an aortic and with an interauricular septal aneurysm too. CASE PRESENTATION: We present a case of platypnea-orthodeoxia syndrome in a 85-year-old woman with patent foramen ovale, interauricular septal aneurysm and ascending aortic aneurysms who was admitted for an acute coronary syndrome which could be of embolic origin and was responsible for ventricular fibrillation during the transfer to the hospital. PFO closure was performed by percutaneous device and right coronary artery obstruction was treated by transluminal angioplasty and stenting.

P1138Cardiac shear wave velocity in healthy individuals.

BACKGROUND: The closure of the valves generates shear waves in the heart walls. The propagation velocity of shear waves relates to stiffness. This could potentially be used to estimate the stiffness of the myocardium, with huge potential implications in pathologies characterized by a deterioration of the diastolic properties of the left ventricle. In an earlier phantom study we already validated shear wave tracking with a clinical ultrasound system in cardiac mode. PURPOSE: In this study we aimed to measure the shear waves velocity in normal individuals. METHODS: 12 healthy volunteers, mean age=37±10, 33% females, were investigated using a clinical scanner (Philips iE33), equipped with a S5-1 probe, using a clinical tissue Doppler (TDI) application. ECG and phonocardiogram (PCG) were synchronously recorded. We achieved a TDI frame rate of >500Hz by carefully tuning normal system settings. Data were processed offline in Philips Qlab 8 to extract tissue velocity along a virtual M-mode line in the basal third of the interventricular septum, in parasternal long axis view. This tissue velocity showed a propagating wave pattern after closure of the valves. The slope of the wave front velocity in a space-time panel was measured to obtain the shear wave propagation velocity. The velocity of the shear waves induced by the closure of the mitral valve (1st heart sound) and aortic valve (2nd heart sound) was averaged over 4 heartbeats for every subject. RESULTS: Shear waves were visible after each closure of the heart valves, synchronous to the heart sounds. The figure shows one heart cycle of a subject, with the mean velocity along a virtual M-mode line in the upper panel, synchronous to the ECG signal (green line) and phonocardiogram (yellow line) in the lower panel. The slope of the shear waves is marked with dotted lines and the onset of the heart sounds with white lines. In our healthy volunteer group the mean velocity of the shear wave induced by mitral valve closure was 4.8±0.7m/s, standard error of 0.14 m/s. The mean velocity after aortic valve closure was 3.4±0.5m/s, standard error of 0.09 m/s. We consistently found that for any subject the velocity after mitral valve closure was higher than after aortic valve closure. CONCLUSION: The velocity of the shear waves generated by the closure of the heart valves can be measured in normal individuals using a clinical TDI application. The shear wave induced after mitral valve closure was consistently faster than after aortic valve closure. Abstract P1138 Figure.Abstract P1138 Figure.

[Management of atrial fibrillation in 2011]. / Prise en charge de la fibrillation auriculaire en 2011.

Some new guidelines have been published by European (2010) and American (2011) Societies of Cardiology regarding to the management of atrial fibrillation, the most frequent arrhythmia affecting from 1 to 2% of the global population. In this article we summarize and analyse the new aspects of these guidelines in which the different types of atrial fibrillation are redefined, as well as new criterias for the indication of oral anticoagulation and bleeding risk. New antiarrhythmic and anticoagulant molecules also appear in these guidelines, and there is growing evidence for the use of catheter ablation.