Early versus late cardiac magnetic resonance in the diagnosis of myocardial infarction with non-obstructive coronary arteries.

INTRODUCTION AND OBJECTIVES: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for about 10% of all acute myocardial infarctions (AMI). Therapeutic strategies and prognosis depend on the underlying etiology, and a multimodal approach is essential. The objectives of this study were to characterize the group of patients diagnosed with MINOCA and to valuate the diagnostic yield of cardiovascular magnetic resonance (CMR). METHODS: This was a retrospective, observational, and analytical study, including 516 patients admitted for a non-ST-elevation MI and with no significant coronary disease on coronary angiography between January 2016 and September 2021. RESULTS: After the inclusion criteria, 163 patients remained of the 516 admitted to the study. They were divided into four groups based on the CMR results: MINOCA (n=51), Takotsubo syndrome (n=37), myocarditis (n=33), and without diagnosis (n=42). Most patients diagnosed with MINOCA were female with a mean age of 61.06±13.83 years. CMR identified the diagnosis in 74.2% of patients admitted for suspected acute MI, in which coronary angiography showed the absence of significant obstructions. The median time between hospital admission and CMR was significantly shorter in the groups that had a diagnosis compared with the group with no diagnosis (p=0.038), with a significant increase in diagnostic profitability if CMR was performed up to 14 days after admission (p=0.022). There were no deaths of cardiovascular etiology during the follow-up period. CONCLUSIONS: CMR was fundamental as it identified the diagnosis in three out of four patients; it should be performed in the first 14 days.

A Case of a Large Malignant Pericardial Effusion on Computed Tomography Without Electrocardiographic Gating.

A 67-year-old female was admitted due to dyspnea. A computed tomography (CT) disclosed a suspicious pulmonary mass and a pericardial effusion. A transthoracic echocardiogram confirmed a large-volume circumferential pericardial effusion. A pericardiocentesis was performed, and the cytological and histochemical studies later confirmed the diagnosis of pulmonary adenocarcinoma. This case report highlights the casualty of having found a cardiac tamponade through a CT not synchronized with an electrocardiogram.

Unveiling an Unusual Cause of Cardiac Tamponade.

This case presents a 48-year-old woman initially diagnosed with an ostium secundum atrial septal defect (ASD) at the age of 36. Twelve years post-intervention, she presented to the emergency department with cardiac tamponade. This case highlights the importance of maintaining prolonged follow-up for individuals undergoing percutaneous ASD closure, given the possibility of potentially fatal late complications of ASD occlusion devices.

Vaccine-induced immune thrombocytopaenia and thrombosis (VITT) after COVID-19 vaccination.

COVID-19 represents a global health emergency, causing significant morbidity and mortality. Multiple vaccines have been distributed worldwide to control the spread of this pandemic. Several reports of thrombosis and thrombocytopaenia have been described after vaccination. These have been termed vaccine-induced immune thrombocytopaenia and thrombosis (VITT). We report a fatal case of VITT after receiving the first dose of Ad26.COV2.S vaccine. A man in his 30s developed thrombocytopaenia, massive haemoperitoneum due to spleen rupture and extensive portal and femoral vein thrombosis. The patient rapidly developed multiple organ failure and died. We attributed this condition to the vaccine due to the temporal relationship, presence of thrombosis and thrombocytopaenia, high levels of platelet factor 4 antibodies and exclusion of other diagnoses. Healthcare providers should be aware of such rare but fatal complications of COVID-19 immunisation, as early diagnosis of VITT may improve prognosis by allowing timely appropriate treatment.

Breast Cancer Stem Cell Membrane Biomarkers: Therapy Targeting and Clinical Implications.

Breast cancer is the most common malignancy affecting women worldwide. Importantly, there have been significant improvements in prevention, early diagnosis, and treatment options, which resulted in a significant decrease in breast cancer mortality rates. Nevertheless, the high rates of incidence combined with therapy resistance result in cancer relapse and metastasis, which still contributes to unacceptably high mortality of breast cancer patients. In this context, a small subpopulation of highly tumourigenic cancer cells within the tumour bulk, commonly designated as breast cancer stem cells (BCSCs), have been suggested as key elements in therapy resistance, which are responsible for breast cancer relapses and distant metastasis. Thus, improvements in BCSC-targeting therapies are crucial to tackling the metastatic progression and might allow therapy resistance to be overcome. However, the design of effective and specific BCSC-targeting therapies has been challenging since there is a lack of specific biomarkers for BCSCs, and the most common clinical approaches are designed for commonly altered BCSCs signalling pathways. Therefore, the search for a new class of BCSC biomarkers, such as the expression of membrane proteins with cancer stem cell potential, is an area of clinical relevance, once membrane proteins are accessible on the cell surface and easily recognized by specific antibodies. Here, we discuss the significance of BCSC membrane biomarkers as potential prognostic and therapeutic targets, reviewing the CSC-targeting therapies under clinical trials for breast cancer.

BR-BCSC Signature: The Cancer Stem Cell Profile Enriched in Brain Metastases that Predicts a Worse Prognosis in Lymph Node-Positive Breast Cancer.

Brain metastases remain an unmet clinical need in breast oncology, being frequently found in HER2-overexpressing and triple-negative carcinomas. These tumors were reported to be highly cancer stem-like cell-enriched, suggesting that brain metastases probably arise by the seeding of cancer cells with stem features. Accordingly, we found that brain-tropic breast cancer cells show increased stem cell activity and tumorigenic capacity in the chick embryo choriallantoic membrane when compared to the parental cell line. These observations were supported by a significant increase in their stem cell frequency and by the enrichment for the breast cancer stem cell (BCSC) phenotype CD44+CD24-/low. Based on this data, the expression of BCSC markers (CD44, CD49f, P-cadherin, EpCAM, and ALDH1) was determined and found to be significantly enriched in breast cancer brain metastases when compared to primary tumors. Therefore, a brain (BR)-BCSC signature was defined (3-5 BCSC markers), which showed to be associated with decreased brain metastases-free and overall survival. Interestingly, this signature significantly predicted a worse prognosis in lymph node-positive patients, acting as an independent prognostic factor. Thus, an enrichment of a BCSC signature was found in brain metastases, which can be used as a new prognostic factor in clinically challenging breast cancer patients.

The Chick Chorioallantoic Membrane Model: A New In Vivo Tool to Evaluate Breast Cancer Stem Cell Activity.

The high plasticity of cancer stem-like cells (CSCs) allows them to differentiate and proliferate, specifically when xenotransplanted subcutaneously into immunocompromised mice. CSCs are highly tumorigenic, even when inoculated in small numbers. Thus, in vivo limiting dilution assays (LDA) in mice are the current gold standard method to evaluate CSC enrichment and activity. The chick embryo chorioallantoic membrane (CAM) is a low cost, naturally immune-incompetent and reproducible model widely used to evaluate the spontaneous growth of human tumor cells. Here, we established a CAM-LDA assay able to rapidly reproduce tumor specificities-in particular, the ability of the small population of CSCs to form tumors. We used a panel of organotropic metastatic breast cancer cells, which show an enrichment in a stem cell gene signature, enhanced CD44+/CD24-/low cell surface expression and increased mammosphere-forming efficiency (MFE). The size of CAM-xenografted tumors correlate with the number of inoculated cancer cells, following mice xenograft growth pattern. CAM and mice tumors are histologically comparable, displaying both breast CSC markers CD44 and CD49f. Therefore, we propose a new tool for studying CSC prevalence and function-the chick CAM-LDA-a model with easy handling, accessibility, rapid growth and the absence of ethical and regulatory constraints.