Histopathological evaluation of coronary thrombi in patients with ST-segment elevation myocardial infarction

ABSTRACTBackgroundPrimary percutaneous coronary intervention (primary PCI) is the preferred reperfusion method in patients with ST-segment elevation myocardial infarction (STEMI). Manual aspiration thrombectomy has been increasingly used and enables the analysis of thrombus aspirates.MethodsConsecutive patients undergoing primary PCI were enrolled from December 2009 to June 2011. Clinical, laboratory and angiographic data were prospectively collected and entered in a dedicated database. The decision to perform thromboaspiration was left to the discretion of the operators. One hundred and twelve samples of thrombi were collected, stored in 10% formalin-fixed paraffin, stained with hematoxylin-eosin and analyzed by light microscopy. On histopathological evaluation, the thrombi were classified as recent thrombi or lysed/organized thrombi.ResultsRecent thrombi were identified in 68 patients (61%) and lysed/organized thrombi in 44 patients (39%). Patients with recent thrombi had higher red blood cell infiltration (P=0.03). There were no other statistically significant differences identified for clinical, angiographic, laboratory or clinical outcomes between the two study groups.ConclusionsIn patients with STEMI undergoing primary PCI, two-thirds of thrombus aspirates showed histopathological features of recent thrombi. There were no significant associations between these characteristics and clinical, laboratory and angiographic data in this contemporary sample representative of the real world