Cellularity and structure of fresh human coronary thrombectomy specimens; presence of cells with markers of progenitor cells.

Acute coronary syndromes and acute myocardial infarctions are often related to plaque rupture and the formation of thrombi at the site of the rupture. We examined fresh coronary thrombectomy specimens from patients with acute coronary syndromes and assessed their structure and cellularity. The thrombectomy specimens consisted of platelets, erythrocytes and inflammatory cells. Several specimens contained multiple cholesterol crystals. Culture of thrombectomy specimens yielded cells growing in various patterns depending on the culture medium used. Culture in serum-free stem cell enrichment medium yielded cells with features of endothelial progenitor cells which survived in culture for a year. Immunohistochemical analysis of the thrombi revealed cells positive for CD34, cells positive for CD15 and cells positive for desmin in situ, whereas cultured cell from thrombi was desmin positive but pancytokeratin negative. Cells cultured in endothelial cell medium were von Willebrand factor positive. The content of coronary thrombectomy specimens is heterogeneous and consists of blood cells but also possibly cells from the vascular wall and cholesterol crystals. The culture of cells contained in the specimens yielded multiplying cells, some of which demonstrated features of haematopoietic progenitor cells and which differentiated into various cell-types.

Angiosarcoma in a pregnant woman presenting with pericardial tamponade--a case report and review of the literature.

Although asymptomatic pericardial effusions are relatively common in pregnancy, their true incidence is not known. Symptomatic effusions are, however, rare in pregnancy. The authors present a rare case of pericardial tamponade complicating pregnancy with resulting diagnosis of angiosarcoma. They review the literature involving pericardial disease in pregnancy and discuss important issues in management and include a discussion of angiosarcoma.

Hemorrhagic pheochromocytoma associated with systemic corticosteroid therapy and presenting as myocardial infarction with severe hypertension.

Pheochromocytomas classically present with paroxysms of hypertension and adrenergic symptoms including headaches, palpitations, tremor, and anxiety. However, these tumors can be clinically silent and occasionally present only when catecholamine release is up-regulated by exogenous stimuli. In addition, the clinical presentation of pheochromocytoma can mimic a number of more common medical conditions, including migraine headaches, cardiac arrhythmias, and myocardial infarction, making diagnosis difficult. In this report, we present the case of a young woman who, while receiving oral corticosteroid therapy for presumed migraine headaches, suffered a myocardial infarction and ultimately hemorrhaged into a previously undiagnosed pheochromocytoma. Our patient exhibited severe, labile hypertension after the administration of iv beta-blockade for presumed myocardial ischemia, raising our initial clinical suspicion for pheochromocytoma. In this paper we review some of the key clinical issues related to this complex case, including steroid-induced stimulation of catecholamine synthesis and release, the role of pheochromocytoma in myocardial ischemia and electrocardiographic changes, and the rare complication of tumor hemorrhage. We then briefly review the essential diagnostic and management strategies for this rare but potentially lethal tumor, with specific emphasis on pheochromocytoma-related cardiovascular emergencies and the surgical management of tumor hemorrhage.

Comparison of coronary artery specific leukocyte-platelet conjugate formation in unstable versus stable angina pectoris.

This study evaluates transcoronary changes in neutrophil and platelet activation and conjugate formation in patients with angina pectoris secondary to coronary artery disease. We examined parameters of neutrophil and platelet activation as well as the neutrophil-platelet conjugate formation in patients who underwent diagnostic coronary angiography. Thirty-nine patients with chest pain referred for cardiac catheterization were studied (23 patients with unstable angina pectoris [UAP] and 16 with stable angina pectoris [SAP]). Before coronary angiography, blood samples were obtained simultaneously from the aortic root and coronary sinus to assess leukocyte (CD11b) and platelet (CD62P) activation and leukocyte-platelet conjugates. There was a 94% increase in CD62-expressing platelets from the aorta to the coronary sinus in patients with UAP compared with a 49% increase in patients with SAP. The percentage of neutrophil-platelet conjugates increased by 22% in patients with UAP compared with a 16% decrease in those with SAP (p <0.01). In contrast, monocyte-platelet binding across the coronary bed increased to a similar degree in both groups. This study demonstrates an increase in neutrophil-platelet conjugates across the coronary circulation in UAP, compatible with a higher activation state in both cell types.