Thrombus architecture is influenced by the antiplatelet loading treatment in patients with acute myocardial infarction.

BACKGROUND: Intracoronary thrombus formation is a main cause of acute myocardial infarction triggered by platelet activation. However, there are no data on the impact of different treatment strategies with antiplatelet agents before percutaneous coronary intervention (PCI) on histological characteristics of thrombus formation. OBJECTIVE: In this study, we investigate the impact of preinterventional administration of the P2Y12-inhibitors clopidogrel and prasugrel on thrombus composition, highlighting significant changes associated with the antiplatelet pre-treatment. METHODS: We prospectively enrolled 104 consecutive patients with ST-segment elevation myocardial infarction (STEMI) undergoing immediate PCI and thrombus aspiration by immunohistochemical staining along with RNA-sequencing employing Nanostring analysis. Fifty-two patients were treated with either prasugrel loading (60 mg) or clopidogrel loading (600 mg) prior to PCI, respectively. RESULTS: In Patients with STEMI, intracoronary thrombus architecture was significantly altered between patients pre-treated with prasugrel when compared to clopidogrel. Fibrin content of thrombi was significantly decreased (41.8 % versus 66.7 %, p = 0.009) after pre-treatment with prasugrel compared to clopidogrel. Furthermore, levels of MPO positive cells in intracoronary thrombi were significantly decreased in patients with prasugrel pre-treatment (90.5 versus 201.1, p = 0.014) indicating an association of antiplatelet pre-treatment and the inflammatory responses during thrombus formation. Most strikingly, we observed significant differences among both pre-treatment groups regarding altered RNA expression and signaling pathways of thrombo-inflammatory processes within the thrombotic material, which were independently associated with antiplatelet strategies. CONCLUSIONS: Our study elucidates the impact of antiplatelet pre-treatment on thrombus remodeling and architecture, thereby lowering the risk of recurrent adverse cardiovascular events in prasugrel-treated patients.

Massive haemoptysis in an intravenous drug user with infective tricuspid valve endocarditis.

Major causes of morbidity in intravenous drug users are infections. In infective endocarditis, the tricuspid valve is mainly involved. Masses can cause septic embolisms and, in rare cases, they are associated with mycotic aneurysms of pulmonary arteries that lead to severe haemorrhage. We report the case of a young woman with a history of intravenous drug abuse and prolonged infective tricuspid valve endocarditis. Initially, echocardiography showed large masses on the anterior leaflet of the tricuspid valve and severe tricuspid regurgitation; blood cultures revealed staphylococcus and streptococcus species. Eight months after initial diagnosis, she presented with severe haemoptysis and fever. CT revealed a ruptured mycotic aneurysm of the right pulmonary artery. Lobectomy was performed immediately. Postoperatively, the patient fully recovered. After continued antibiotic treatment, follow-up examinations showed negative echocardiographic findings and blood cultures results.