Infective endocarditis (IE) is a serious infection of the inner surface of heart, resulting from minor lesions in the endocardium. The damage induces a healing reaction, which leads to recruitment of fibrin and immune cells. This sterile healing vegetation can be colonized during temporary bacteremia, inducing IE. We have previously established a novel in vitro IE model using a simulated IE vegetation (IEV) model produced from whole venous blood, on which we achieved stable bacterial colonization after 24 h. The bacteria were organized in biofilm aggregates and displayed increased tolerance toward antibiotics. In this current study, we aimed at further characterizing the time course of biofilm formation and the impact on antibiotic tolerance development. We found that a Staphylococcus aureus reference strain, as well as three clinical IE isolates formed biofilms on the IEV after 6 h. When treatment was initiated immediately after infection, the antibiotic effect was significantly higher than when treatment was started after the biofilm was allowed to mature. We could follow the biofilm development microscopically by visualizing growing bacterial aggregates on the IEV. The findings indicate that mature, antibiotic‐tolerant biofilms can be formed in our model already after 6 h, accelerating the screening for optimal treatment strategies for IE.

Background/Introduction The general atrial fibrillation/flutter (AF) population is well explored and described, but there is sparse data on temporal changes in the incidence, AF-readmission rates, and practice patterns in patients with AF under 65 years of age from unselected cohorts. Purpose To investigate temporal changes, AF readmission rates, and practice patterns in patients under 65 years of age with first-time AF diagnosed between 2000–2018. Methods Using Danish nationwide registries, we identified patients >18 years and <65 years with a first-time AF-diagnosis from 2000–2018. The cohort was categorized according to calendar periods; 2000–2002, 2003–2006, 2007–2010, 2011–2014 and 2015–2018. Incidence rate (IR) of AF per 100,000 person years (PY), AF-readmission, and practice patterns of medical treatment, electrical cardioversion, and catheter ablation was investigated in the first year following AF-diagnosis. Results In this study 60,917 patients were included; 8,150 patients (13.4%) in 2000–2002, 11,898 (19.5%) in 2003–2006, 13,560 (22.3%) in 2007–2010, 14,167 (23.3%) in 2011–2014 and 13,142 (21.6%) in 2015–2018. No major differences were seen in patient characteristics according to calendar period. A stepwise increase, as seen in the Table, in the crude IR of AF per 100,000 PY was observed across calendar periods, except for 2015–2018 (Crude IR [95% CI]: 2000–2002: 78.7 [77.0; 80.4], 2003–2006: 86.3 [84.7; 87.8], 2007–2010: 97.9 [96.3; 99.6], 2011–2014: 102.3 [100.7; 104.0], 2015–2018: 93.6 [92.0; 95.2], while no difference in AF readmission was identified (AF-readmissions: 2000–2002: 32.7%, 2003–2006: 31.1%, 2007–2010: 32.2%, 2011–2014: 32.1% and 2015–2018: 31.7%), as seen in the Figure, right panel. In the first year following AF-diagnosis, the cumulative incidence of catheter ablation increased stepwise from 1.2% in 2000–2002 to 7.6% in 2015–2018 and electrical cardioversion from 2.0% in 2000–2002 to 8.7% in 2015–2018 (Figure, left panel). Treatment with oral anticoagulant therapy (OAC) increased from 28.5% in 2000–2002 to 47.8% in 2015–2018, while there was no change in treatment with rhythm or rate medication therapy. Conclusion From 2000–2018, we found an increase in the incidence of atrial fibrillation/flutter (AF) in patients <65 years from 78.7/100,000 person years (PY) to 93.6/100,000 PY and an increase in the use of catheter ablation, electrical cardioversion and OAC in the first year following first-time AF-diagnosis. AF readmission rates were stable over calendar periods. Funding Acknowledgement Type of funding sources: None.

Introduction: Hidradenocarcinomas are very rare and aggressive soft-tissue tumors, originated from sweat gland cells, which are located most frequently in head and neck, being their appearance at the extremities rare. This kind of tumor usually appears de novo and very few cases have been reported until now of appearance over benign lesions such as hidradenomas. Malignancy progression rate of hidradenomas is unknown, and this benign lesion has clinical and histopathological characteristics in common with hidradenocarcinomas that could lead to misdiagnosis. Hidradenocarcinomas have a very poor survival rate; therefore, an early diagnosis is essential for a better prognosis, and that is the reason why hidradenomas should be widely excised from the beginning, instead of performing marginal resections of this lesions that could lead to an aggressive recurrence. Case Presentation: Here is a case report of a 27-year-old woman diagnosed with a hidradenocarcinoma over a previously excised hidradenoma in the right foot. The diagnosis was made after right pelvic and inguinal lymphadenopathies appeared few months after a new small asymptomatic lump appeared at the same place in the sole of the right foot were the excised hidradenoma five years before was located. Lymph node biopsy was performed, with histopathological diagnosis of hidradenocarcinoma metastasis. Surgical local wide excision of the lump at the foot and lymphadenectomies was performed. Histopathological analysis of the samples confirmed the diagnosis of hidradenocarcinoma. The patient later received adjuvant radiotherapy and after one year there are no signs of disease recurrence. Conclusion: Many questions remain uncertain about the management and treatment of hidradenocarcinomas due to the rarity of this type of tumor. Although targeted molecular therapies have shown promising results, more studies in this field are necessary. An early diagnosis and differentiation from its benign counterparts that allow local control of the disease before spreading is essential to improve survival rates.